Solar DIY Space Heating Projects

Plans for a wide variety of solar space heating projects you can build.

Solar space heating can be 25 or more times more cost effective than solar electric (PV) systems, and the systems are excellent DIY projects.  Payback for these low cost solar heating systems can be as little as one year.

Directory for this page:

Information on pumps, heat exchangers, heat storage tanks, controllers, pipe insulation, backdraft dampers and other components for solar space heating systems here...


More ideas on homemade Solar Space Heating ...

Report Broken Links ...

Basics and Guides
Solar Site Survey ...


Before you embark on any of the solar projects listed below, you MUST do a solar site survey.
This will ensure that you actually get enough sun on your collector to make it worthwhile.
It only takes an hour, its fun, its easy and you will learn something about how the sun moves.      Solar Site Survey...
Solar Heating and You (pdf)

Energy Efficiency and Renewable Energy Clearinghouse


A high level (but useful) introduction to solar space heating concepts.   Includes solar flat plate collectors, and sunspaces. 
Includes an interesting and easy experiment you can perform using an existing window and some cardboard.
A good intro for adults and kids.
Passive Solar Energy Book (to download)

Bruce Anderson and Malcolm Wells

The first two chapters provide some solar space heating basics, the other chapters provide details on direct gain, sunspaces, ...


A great book covering passive solar basics, passive solar design, and building of passive solar heating and cooling projects such as solar rooms, solar windows, solar walls, and solar thermosyphon collectors.

A free download thanks to the authors.

Solarizing Your Present Home -- Practical Solar Heating Systems You Can Build, edited by Joe Carter, Rodale Press, 1981

Out of print, but readily available at libraries and online used book places .

A good book covering a range of possibilities for retrofitting solar space heating to your home.  The 670 page book covers a large number of projects in good detail.

More information...
Out of print, but readily available at libraries or online used book places.

Solar Livestock Housing Handbook,
MWPS-23, Iowa State University


This 90 page page book goes through a solar 101 course, and then goes on to cover the design and sizing of several types of solar collectors, and then gives fairly detailed descriptions of 11 solar collector examples. 
While it primarily addresses AG applications of solar, many of the ideas are interesting and and potentially applicable to other solar heating situations. 

(Thanks to Greg for re-finding this book)

Thermal Storage Wall Design Manual
Alex Wilson 
New Mexico Solar Energy Association

Thermal Storage Wall Design Manual

The New Mexico Solar Energy Association website ..

This 43 page booklet on thermal storage wall design and construction provides a full design procedure for Trombe and Water Walls, and a great deal of how-to build material as well.  Measured performance is provided for several actual thermal storage walls.  While some of the material is a bit out of date, it is a very valuable and practical resource.

I feel like I had a small part in this, in that I found a copy of this booklet in our local library, and scanned it in so that the NMSEA could put it online.  This book is part of the NMSEA technical library.  Their technical library is very extensive, and they are trying to work out a way to get more of it online -- you might give them some encouragement in this direction, or volunteer to help them!  More info here:
Pump and Plumbing Sizing for Solar Water or Space Heating System

Details on solar pump/pipe sizing...

This page covers the details of sizing the pump and the plumbing for a solar space or water heating system so that the system efficiently transfers heat from the collector to the storage tank without being excessively large.

Details on solar pump/pipe sizing...

Solar Thermal Resources
Florida Solar Education Center

FSEC Solar Thermal Resources Pages (very good):

FSEC's main page on solar water heating...

Good detailed section on system installation including collector mounting, plumbing, tank, ...

The Solar Thermal Manual provides a good description of the various types of solar water heating systems, as well detailed sections on installation and troubleshooting -- lots of detailed how-to.  Very useful.

Also, good Installation Pictorials for the entire solar water heating installation.

How Much Collector Area Do I Need To Heat My House?

Or, Estimating Solar Heating Fraction

Details ...

This is a question I get asked a lot.  Its a tough question that depends on many things, but here is a method that you can use to get a pretty good idea what your solar faction is likely to be for your collector array...

Its fairly lengthy to use, but not difficult.

Side by side performance testing of several DIY solar air heating collector designs...

solar air collector testingTwo of us did independent side by side testing of several common air collector designs during the winter of 2010 - 2011.  While IIR of solar collector test consider the results tentative and hope to do more this winter, I think the results are useful and somewhat surprising.
Bottom line is that the simplest construction collector (the screen absorber) is also the most efficient of those tested -- a happy surprise.  Details here...
Passive Space Heating
Solar Barn/Workshop


Jan 2012: Major update -- new testing on: efficiency & vent size, recommended design refinements, commercial version, maintenance record...

Dec 2006: This project is the cover story in Mother Earth News Dec/Jan 2006/7 issue and was in the Oct/Nov 2005 issue of Home Power Magazine.

A simple, low cost thermosyphon solar space heater for a garage, barn, or workshop (or maybe for a more finished space with some changes). 

On a dollars per BTU of output, this collector is about 25 times more cost effective than a popular commercial solar air heating collector.  At current propane prices, the project has a one year payback.

The lack of fan and controller makes the collector easier to build and more reliable. 

A Lare Shop Thermosyphon Solar Air Heating Collector...


large thermosyphon solar shop heating collectorThis is Ivan's very nice thermosyphon solar air heating collector that heats his shop.

It is 6 ft high and 40 ft wide for a total of 240 sqft.

This is a thermosyphon collector, so it needs no fans or controllers or electricity -- very simple and quite efficient.

Lots of good detail on the build and lots of interesting ideas in Ivan's design.

Rob's Thermosyphon Solar Heater ...



This is similar to the thermosyphon collector described above, but used for home heating rather than shop heating.

It fits into the house very nicely both inside and outside.

All the details ...

Thanks to Rob for providing this.

Garage/Workshop Sunspace  --  Full Details ...


The Home Power Magazine article on this project is now available here as a download


NEW!    Fred's solar shop doors get written up in the paper:

Home Power Magazine article -- issue 117 Feb/Mar 07.

This is a simple way to turn your garage into a delightful solar heated and lighted workshop or studio.

My all-time favorite Do-It-Yourself solar project!


An Alternative to Building Your Own Doors:  Here is a variation on this scheme suggested by Ed that uses commercially available doors instead to the home made doors .   Details ...


Another alternative from Scott:

"I had a tent company sew a giant clear vinyl curtain to cover my garage door. Put a zipper on both sides, and can roll it up when not needed. Cost me $200 total. Works great as my garage faces south."
Pictures and details...

Adding a Window as a Solar Collector

Plans for solar window

A plan excerpted from the book "Passive Solar Energy", Anderson and Wells

Adding a window to a south wall makes a very effective and efficient solar collector.
These plans show a way to add a window to a south wall using very simple window framing -- much less expensive than adding a commercial window.
Thermosyphoning Air Collector

Plans for Thermosyphoning Air Collector

A plan excerpted from the book "Passive Solar Energy", Anderson and Wells


This is a very simple and cost effective solar heater which can be retrofitted to an existing house, or used in new construction.

It uses natural convection -- no blowers, ducts, or controllers needed.

Solar Wall (or Trombe Wall)

Plans for Solar Wall

A plan excerpted from the book "Passive Solar Energy", Anderson and Wells


The solar wall or Trombe wall is a simple way to provide solar heating from a south facing masonry wall.

The wall stores heat and releases it gradually late in the day.

A Water Wall Solar Design Manual (2 MB pdf)
David Bainbridge
Marshall Goldsmith School of Management

More information on Water Walls from David ...


Water walls offer cost effective, efficient, and aesthetically pleasing thermal storage for passive solar heating systems.  This design manual covers many types of water walls, and shows how they can be used in solar designs to provide thermal mass.

David is also the author of this fine book on batch water heaters

A Passive Solar Space Heater For Home Use,
Worcester Polytechnic Institute



Note that there are 3 collectors on this page, this description applies to the bottom one -- "A Passive Solar Space Heater for Home Use"

This solar space heater takes advantage of existing windows to avoid cutting holes in your house.  You could probably do it on a rental.  Very simple -- no fans, no wiring.
It will provide more heat than the small window attached collectors below, and has a hinged cover that protects the collector in the summer, and reflects more sunlight onto the collector in the winter.  You do not want to allow the sun to shine through the glazing onto the ground (it will just lose heat to the ground) -- have something to intercept the sun in the collector space.  The glazing could be the Sunlite HP mentioned, or corrugated Polycarbonate.
Collector area makes more difference than any other parameter, so make it as big as you can -- size maters in solar collectors.
Solar Heated Ice Fishing Shack

All the details from Bob...

Solar collectors are not just for heating homes -- Bob uses this very simple and effective thermosyphon solar air heating collector to heat his ice fishing shack.

It cost almost nothing to build, and heats the insulated fishing shack very well.

All the details from Bob...

Solar window heater

A simple solar thermosyphon heater that connects directly to a window.

Maine Solar Primer "Sun Grabber"

Maine Solar Energy Association


Plans for a simple thermosyphon air collector that connects to an existing window.

Courtesy of the Main Solar Energy Association

DIY Solar Heating with the Heat Grabber, editors

Mother Earth News

Finding Mother Earth News articles...


A nice complete set of plans to build a below window solar collector.  The collector uses a small part of the bottom of an existing window for the entry and exit vents.


“TAP” The Sun – The easy, low-cost way to add solar heat to your mobile home or metal outbuilding.

Luke Elliot

Finding Mother Earth News articles... 




Mother Earth News Article, Issue 91 Jan/Feb 1985

How to article on building a Thermosyphoning Air Panel (TAP) solar collector to heat a mobile home or a metal walled building.  Sufficient detail to build the project.  This 18 sqft collector costs less than a hundred dollars in materials. 
This is a durable metal and glass construction collector, and should last the life of the building.

Maine Solar Primer Air Heater

Maine Solar Energy Association

A simple, wall mounted thermosyphon solar air collector.

Courtesy of the Maine Solar Energy Association

Solar Ventilation Wall With Heat Storage

Canada Plan Service

Download Plans pdf

A solar heating scheme for a barn or shop that integrates a thermosyphon solar collector and thermal storage into the south wall of the building.

From the Canada Plan Service:

Integrating Light Transmitting Sheets for Skylights in Roofing and Siding -- Installation Guide

From Suntuf

Details on how to integrate plastic glazing panels in roofs or walls to provide lighting and solar gain.

From the Suntuf website

Passive Solar Shop Heating

Canada Plan Service

Download Details  (pdf)

Plan (pdf)

A very simple and inexpensive solar heating scheme for shop or barn that integrates a thermosyphon collector into the south wall structure.

From the Canada Plan Service:

Solar Heating a Workshop in Madison County, Iowa,
DeSoto Solar  



This very nice project description shows a fairly large installation of DeSoto solar air collectors for shop heating.
One interesting aspect of this installation is how well the collectors are integrated with the shop wall, and how nice the collectors look from the outside and inside -- seems like this approach would work just as well in a house.
DeSoto Solar is run by Morris Dovey who can usually be found at the newsgroup.
A $1 per square foot Trombe Wall

Nick Pine

Nick's wall

This is a really simple way to turn an ordinary uninsulated masonry wall into a passive solar Trombe wall.  Costs about a buck a square foot, and no holes to punch in the wall.
Solar Heated Pig House, Murphy
Mother Earth News, May/June 1979

Finding Mother Earth News articles...

There are two MEN articles.


This is actually a pretty slick and simple 1979 solar air heating collector.  It is integrated into the barn style roof, and would be very inexpensive to build.  The increase in price over a conventional roof would be quite small -- maybe less than $1 per sqft!
Seems like it would also work well for gambrel roofs on the steep slope.
This one is used for heating a swine barn, but it could as easily be used in two legged applications.
A Crude Poly Mini-Sunspace Heater

Mini Poly Sunspace


A very simple poly sunspace for heating.
This was a quick and dirty project just to see if the idea worked at all.  It did.
Keeping the pipes from freezing when away

Full Details ...


Several methods to keep the pipes from freezing in your home or vacation home when you are away without burning fuel.

Includes plug in window solar collector/insulator panels, and a plumbing drain system, and others...
Full details...
Build a Simple Solar Heater With a Sheet of Plastic,

Finding Mother Earth News articles... 


Mother Earth New, Sep/Oct, 1976. 
This is a very simple thermosyphon solar air heater that was built for $25!

If you don't like the look of the black plastic, you could instead hand a dark shade of shade cloth, or just paint the wall and dark shade.  Substituting something like SunTuf polycarbonate glazing would eliminate the chore of replacing the glazing film every year or so.
Active Space Heating -- Water Heating Systems
The new $2K Solar Space + Water Heating System

Table of Contents for this project...

This is a very simple system you can build using simple tools, ordinary DIY skills, and local materials. This simple system provides high performance domestic water heating AND space heating.

The system is well documented with over a hundred pages of how to design and build the system for your situation.  Many other alternatives are discussed along the way.  I recommend going through this project if you are new to solar space or water heating to get a good understanding of the potential for these systems.
Tom's 330 sqft Solar Space Heating System

Full design and construction details...


Tom's other projects fine on BuildItSolar...

Tom's very well done  solar system for heating the house and domestic water heating.  This is a great project with details on design and construction of a large solar collector array, a large thermal storage tank that doubles as a work bench, integrating solar and wood boiler heat sources in the same system, a very nice heat exchanger fabricated from rigid copper pipe, and details on integrating radiant heating with solar. 

This is Tom's 3rd generation of building solar water heating collectors, and he has incorporated refinements in each generation -- the collectors are  efficient and well proven..
The Solar Shed for House Heating

Solar Shed House Heater


Solar Shed article in the Dec 2007 Mother Earth News ---------->

Some great new illustrations, diagrams, and full how-to build information.

This is the setup I use to solar heat my house.  It uses 240 sqft of solar water heating collectors mounted on a new garden shed.  Heat is stored in a 500 gallon tank that lives in the shed.  Heated water is piped to the house as required via insulated underground pipes.
Excruciating detail is provided :)
Solar Space & Water Heating System -- With Folding Collectors!

All the details...

This is a very well done space and water heating system.  It has a unique folding collector arrangement that varies collector area by season.  Kenneth is a very good craftsman, and has worked out some good new tools and techniques for building collectors.
All the details...

Serpentine Drainback Solar Space Heating Project and Design Manual...

large serpentine drain back collectorThis is a very unique solar space heating collector. The absorber covers the entire south wall right to the peak -- this is made possible by using an absorber that is plumbed with tubes in a serpentine pattern rather than they usual vertical riser pattern. The serpentine pattern allows the absorber to be fit to the entire wall area and to extend all the way up to the peak. The full wall glazing makes for a very nice looking collector.

Several other unique features on the system, including a partitioned tank for more efficiency.

The builders provide a very complete 36 page manual that details the design and build in great detail...

Large DIY Solar Space Heating System in Maine

All the details...
large solar space heating collectorThis is Steve's very nicely done solar space and water heating system.  The system uses a 28 ft wide drain back Hizer design collector.  The collector is coupled to a non-pressurized, EPDM lined heat storage tank.  The solar space heating is integrated with the regular boiler system. 
The system has several unique features including a homemade controller, and a method to recoil the PEX heat exchangers for improved heat transfer. 
Steve provides a pdf with full details on the design and build....

Solar Hot Water and Space Heating System With Integrated Boiler

All the details on Norm's space and water heating system...
solar space heating systemNorm's system uses a large homemade solar heat storage and drain back tank to provide solar space heating and domestic water heating for his home in Maine. 

The system uses a set of Norm made copper coil heat exchangers that are beautifully done.
The system integrates the solar heating with a boiler that provides the space and water heating functions when the solar water is not hot enough.
Rob's Solar Hot Water Project With Space Heating and Cooling

All the details on Rob's solar heating system...
solar water and space heating systemRob's solar water heating system provides domestic water heating and some space heating (and maybe cooling next summer). 
Its the first drain back system I know that uses the "hizer" (horizontal risers) design.  Heat transfer to the house is via a water to air heat exchanger in the furnace ducting.
Rob provides 42 pages of detail on design and construction.
Space Heating System in Vriginia solar space heating system Vriginia

This is a very nicely planned and executed solar heating project in Virginia. Lots of detail on all phases of the project with sections on planning, installation, costs, and performance.

The system is modeled after our $2K system, but with many adaptations and innovations to suit Kevin's home and climate.

A 25 page pdf explains the whole project.

All the details...

Solar Heat for My Maine Workshop
Guy Marsden

Guy's outstanding website:

How to get articles from Home Power ...

Home Power magazine article, issue 89

Excellent article on designing and building a solar radiant floor system for a detached workshop. Lots of design and construction detail. Blow-by-blow construction highs and lows also described.

South Wall Integrated Solar Space Heating System


All the details: NOTE: link not working -- leaving this here on chance Jim will let me know where it lives now.

Update Feb 2013: This is a really nice project, and very well documented.  Jim is adding material this summer on a control system with live data and an interconnection with his wood stove.  He has not turned the furnace on in 2 years. 

This is a detailed description of Jim's solar space heating system.  Jim was able to add quite a bit of solar collector area to his existing home in a very aesthetically pleasing way.  The collectors were made by Jim and friends using commercially available absorber plates.
This is a drain back system with a large, fiberglass storage tank.  Note the seasonal use of reflectors that increase collector output by about 20%.  Lots of good detail on Jim's site about the project.
Paul's House Heating -- Solar Shed

Details here...

A solar hot water heating system with capacity for future space heating. 
Collectors are mounted on new storage shed with hot water piped to house.
A well done system at a very low cost.
Details here...
Large Horizontally Oriented Water Heating Collector with a Unique Heat Storage System

All the construction and performance details...
solar space heating system This is a really nicely done water heating system from Bob and Dave.   The system uses a unique collector design in which the "risers" run horizontally instead of vertically -- for a wide, built in place collector like this, the horizontal riser arrangement saves materials and labor.
The system also has a unique heat storage vault that makes use of a bank of barrels in an insulated enclosure. 
Lots of good design, construction, and cost data...
Large Drainback System for Home and Hot Tub

Eric's site home page:

This is a very nicely designed and built system by Eric.  The system includes 320 sqft of drainback collector supplying heat for both Eric's home and hot tub.  The storage for the system is a precast underground tank that is quite cost effective.  A conventional boiler is integrated into the system for back up heating.  A very nice system explained well.
Thom's 24 X 8 Solar Space & Water Heating System



This is a nicely done and large solar system that provided both space and domestic water heating.    This is a drain back system with the storage tank located 50 ft away from the collectors in the house.  The collectors are modeled on the $1K design.
Thom put a lot of thought into this design, and provides a lot of detail. 
There is also a very good section on what to do when things don't work quite right at first.
Scott's 24X8 ft Solar Space Heating Collector

Details ...


This is Scott's very unique collector.  It is built as one single unit that is 24 ft wide by 8 ft high.  The absorber is a wide version of the PEX/aluminum collector.
The ground mount and single unit construction make for an attractive and easier to build collector.  Details ...
Ken's Large Solar Water (plus) Heating System

All the details on Ken's system...

This is a very nicely done solar water heating system that generally follows the $1K design, but includes 200 sqft of collector and a larger tank to provide excess capacity for hot tub and space heating.

Very nice workmanship, and the tank and heat exchanger show some well thought out variations that you might want to adopt.

Chad's Solar Home Heating System

Details here...


Chad uses 6 4X8ft collectors mounted on his shop to heat his home, which is 200 ft away.  The collectors are based on these copper/aluminum collectors with some refinements for Chad's situation.  The collectors pivot to allow the tilt to be adjusted.
This is a closed loop system with antifreeze for freeze protection.
Details here...
Kris's solar water and space heating system


This is Kris's very nicely done solar space and water heating system. 

Lots of details on tank and heat exchanger design.  Lots of nice clean mechanical details.

A Sustainable Solar Heated Loo


This solar heated loo shows how simple a solar space heating system (with heat storage) can be. The IBC heat storage tank both stores heat and distributes it to the "room". Its a simple drain back system with a PV driven pump -- only one moving part (the pump) in the whole system.

a solar heated looThis is Michaels very nice solar heated loo. It uses the Arbor Loo design, but adds a simple solar space heating system to help out on those solar heated loo diagramcold mornings.

The Arbor design saves thousands of gallons of water a year, and provides valuable compost.

The solar heating system is simple and compact drainback using an IBC container for the heat storage and heat distribution.
All the details...

Solar Water Heating Using a Unique Master and Slave Collector Design

Full details Gordon's new solar water heating system...

Note: This is a solar domestic water heating system, but I include it here because the Khanh collector design could also be used for space heating.

Gordon's deep energy retrofit of a schoolhouse into a very low energy use home...

This is a very unique solar water heating system with several innovative features:
- It uses a Khanh Master/Slave collector to improve collector performance.
- The storage tank uses a low profile galvanized metal livestock tank.
- The heat exchanger is multiple coils of small diameter copper pipe in parallel.

Gordon also shows how a drain back system can be adapted to a difficult situation.
Full construction detials...

Near Zero Energy Solar Upgrade of a New Mexico Home


All the details on Greg's design and build...

solar zero energy home

This is Greg's solar heated remodel in NM.  The combination of improvements to the homes' thermal envelope coupled with aSolar heat storage tank solar space heating system with lots of heat storage make this a zero energy home for space and water heating.  When the  planned PV array is completed, it will be a full net zero energy home.

All the details on Greg's design and build...

Solar Collectors on Shipping Container Direct to Slab Heating

Details on the project...

Their newer site has a bit more...


shipping container solarIn this project, a bank of site built solar water heating collectors are mounted on a salvage shipping container.

An interesting thing about the project is that the hot water generated by the collectors is run directly to pex tubing to heat a slab in a nearby building. There is no storage -- the slab is the storage.

The site is hard to find the posts of interest, but the two links to left should get you started. The posts are labeled "Solar Sundays Part XX" where XX goes from I to IX.

Low Cost Solar House Heating

Chester Johnson and Joel Chinkes


How to get articles from Home Power ...

Home Power Magazine article, issue 59

Very good article on a solar hydronic heating system.  Home made solar collectors of a unique design heat water to circulate in a radiant floor heating system.  Good construction detail.  Very simple system.   Very cost effective.

DIY Combination Solar Water and Home Heating System
Renew Magazine Article

Article (260  pdf)

Article from Renew Magazine, Issue 80

Interesting article on a very large and completely home built solar collector and storage system.

The Thomason Trickle Collector



Dr. Harry Thomason invented the simple solar collector that heats water by trickling it down the channels of a corrugated roof under glazing.  This very simple collector is used in a number of residential and commercial building.  He also invented an number of other solar heating and cooling concepts. 
These descriptions of Dr. Thomason's patents and related articles provide quite a bit of design information.
(thanks to Nick Pine for providing these) Solar Heating System

The main page provides access to quite a bit of interesting solar material.

NEW: Update on the  sand bed storage system:

This is an interesting active solar heating system that uses 400 sqft of solar water collectors to circulate solar heated fluid through a 100 ton sand bed below the house floor.
A fairly detailed description of the system is provided. 

Hydronic Heating for Low Energy Houses,
John Siegenthaler,



A very good and very detailed 167 page presentation of heating systems for energy efficient homes.

Extensive discussion and details on various hydronic heat distribution systems and heat sources (including solar).

Hydronic Heating on Renewable Energy
Rod Hyatt

How to get articles from Home Power ...

Another good general article on radiant heating:

Home Power Magazine article, issue 79

Very good article on implementing a hydronic radiant floor heating system in an off grid house using PV powered pumps. Lots of detail on installation of the hydronic heating system.

Radiant Floor Company




Lots of good installation and design detail on this site.
Radiantec -- radiant floor heating systems 

Installation manuals:

Info Library:


Radiantec provides a several useful manuals on the design and installation of radiant floor heating systems, including systems with solar heat sources.
The Library provides quite a bit of material on solar heating fundamentals, papers, ...
Manual of Modern Hydronics,

Sections 1-4... (pdf)
Sections 5-8... (pdf)
Sections 9-12... (pdf)
Appendix... (pdf)
Components... (pdf)


Very good manual on designing and installing hydronic heating systems.  Does not include any information on solar as a heat source, so look to the other refs listed in the section for that, but solar works well as a heat source for radiant floor heating.

This manual used to be available at the Ipex/Warmrite site, but no more, so I'm temporarily providing copies here.  If you know of an "official" source, please let me know.


This is a software package from WattsRadiant for designing radiant floors.


Calculators: radiant heat sizing, heat loss...

Borst Engineering and Construction provides a number of calculators that are helpful for designing radiant floor heating systems.

They are a small engineering consulting and analysis business -- "We are do-it-yourselfers (DIY) at heart and we support like-minded people"

Radiant Floor Retrofit Details

Radiant Floor Company

The Details Page:

Heat Sources:

The Radiant Floor Company provides some nice detail on several ways to install  a radiant floor either in new construction or as a retrofit.  Good pictures.

Radiant floor heating works well with solar because it can make use of relatively low temperature hot water that solar systems produce more efficiently. 
I would be more careful about insulation issues than they are in places.

Infloor Radiant Heat Downloads

Infloor's download page includes some useful information for doing solar radiant floors.

Including, A fairly detailed 68 page radiant floor design manual.
Green From the Ground Up,
Jim McKnight, Mark Klein & Laura Lee,
Home Power magazine issue 122

How to get articles from Home Power ...

Description of a home that combines an efficient envelope, solar passive heating, solar hot water, masonry heater, and solar electricity to produce a very efficient and green home.
The radiant floor heating system can accept heat from solar, the masonry heater, or a gas boiler via a shared heat storage tank.
Insulation Under Radiant Slabs ... (pdf) (this pdf has gone away)

Another test of slab insulation...



Good article on under slab insulation for radiant heated floors.

Compares three types of insulation to no insulation.
Rigid foam insulations do well, but the bubble pack style of insulation is worthless.

Double Play -- An Experimental Solar Heating and Cooling System
Steve Baer

How to get articles from Home Power ...

and the Zomeworks site
Search the Zomeworks site for "Double Play"

Roof Integrated Solar Absorbers
Home Power magazine article, issue 102

This innovative system uses unglazed collectors that are integrated with the roof structure and a unique thermal storage system to provide solar thermal heating in the winter and radiation cooling in the summer. Amazing!

The pdf report provides detailed performance measurements from the FSEC & NREL.

This scheme is perhaps a bit on the bleeding edge, but it seems promising to me, and might be good for the adventurous.

Hot Water Floor Heating for Barns Design Guide

Canada Plan Service

Design Guide For Hot Water Floor Heating (pdf)


This guide is intended for the design of hot water floor heating systems for barns, but has design information that may be useful for workshops etc.

From the Canada Plan Service:

Making or Buying Collector Fins
How to make collector fins and evaluate collector fin designs

How to make and evaluate collector fin designs...

This article covers the various ways people have worked out for making the heat absorbing fins for collectors, fin performance, and some construction tips.

How to make and evaluate collector fin designs...

The next 4 Entries from the Experimental Section.

The first 2 are collectors that I developed for my home solar water heating system.
The 3rd entry is for the MTD (Modified Trickle Down) collector being developed by John Canivan and Richard Heiliger.
The 4 th is a design developed by Scott Davis that uses CPVC for the absorber -- a very easy build.
While I would still consider them experimental, I think they are pretty solid as long as you stay within the limits that are detailed.
I think all three of these have very good potential for inexpensive, high performance, long lived solar heating collectors.

A $6/sqft solar collector using Copper tubing and Aluminum fins

Full Details ...


This collector is an offshoot of the collector just below.  It uses the same scheme to transfer heat from the aluminum fin to the heat transfer tubing, but copper is used instead of PEX for the tubing.  This adds a modest amount to the cost per sqft, but provides performance that is quite close to all copper commercial collectors.

This is a cut at a solar water heating collector that offers a combination of high performance with a low cost per sqft, and an easy build.
See what you think!

The fin to tube thermal connection is similar to the collector above, but copper is used for the tubing instead of PEX.  This provides performance within 4% of an all copper collector in an easy to build package.

Extensive build, testing, and performance information is provided...


A $4/sqft solar collector using PEX tubing and Aluminum Fins

Full Details...


There has been a lot of interest in a collector that uses PEX tubing rather than copper to convey the heat transfer fluid.  Here is a cut a collector that does this -- with careful attention to the PEX/fin joint, it can perform surprisingly well. 

This is a cut at a solar water heating collector that uses PEX tubing instead of copper to convey the heat transfer fluid.   The fins are aluminum, and a lot of effort was put into attaining a good thermal bond between the PEX and aluminum.  Testing indicates that the collector performs at 84% of and all copper commercial collector at about 1/7th the price.

Extensive build, testing, and performance information is provided...

Comparing the Performance of Two DIY Solar Water Heating Collectors -- CPVC vs Copper


All the details on CPVC collector performance test...

cpvc solar collector testI did a side by side test of  Scott's new design cpvc solar collectorof the CPVC/aluminum collector comparing it to the  copper/aluminum collector. 
The performance of the CPVC collector was good, and I think that this CPVC design offers another option for DIY solar collectors.

The CPVC collector is easy to build and would make a good first solar project. 

All the details on CPVC collector performance test...
Modified Trickle Down Collector (MTD)

Richard Heiliger's detailed descriptions of the two versions of MTD collectors he built ...







John Canivans website with more MTD information ...

These are two new versions of the Thomason Trickle Down Collector from Richard Heiliger.
They use less expensive materials, are easier to build, and are likely to be more efficient.


Version 1: This design uses all plastic internals with a metal frame.  The emphasis is on low cost and ease of construction with good durability.

Version 2 This design uses all metal construction with a felt coated metal absorber, and a metal frame.  The emphasis for this design is on high durability and long life. 

Both designs are well thought out, perform well, and are described with great "how-to" detail (more than 80 pages of construction detail all told).

Full descriptions ...

Active Space Heating -- Air Heating Systems
Solar Air Heating Systems

Steve Kornher with Andy Zaugg

Download this book


This is a fine book on designing and building solar air collectors and solar air heating systems of many types.  Very good on design, very good on construction.  Covers both active and passive air collectors.  Highly recommended.
Solar Air Heating Collector Performance Tests -- Which DIY Collector Design is Most Efficient?

All the details on DIY solar air heating collector comparisons...

Construction details for the screen collector -- the best performer...
solar air heating collector side by side testsThis is a full winters worth of side by side testing of several DIY solar air heating collector tests.downspout solar air heating collector

Scott and I did independent testing of several designs, with each design tested side by side with the same baseline collector.
The surprising outcome was that the simplest and cheapest design did very well.

Model-TEA Solar Heating System - Construction Manual, Peter L. Temple, Jennifer A. Adams


Full details ...


TEA solar diy collectorThis 1980 book describes a solar air heating system using a solar air heating collector.  The collector is integrated into the roof or wall, and can be quite large -- up to several hundred square feet.  
The design is very well thought out, and extensive testing was done on the design to assure high performance and long life.  The collectors are: simple in construction, use commonly available materials and tools, and look great. Integrating the collectors into the home structure saves materials and labor.  
The book covers system sizing, collector construction, heat storage  construction, and a ducting, fan and control system.  The construction drawings and instructions are very detailed and very well done.

Thanks to the Peter for allowing this material to be made available 


MOFGA Solar Air Heating Collector,
Maine Organic Farmers and Gardeners Association


This solar air heating collector utilizes the full south wall of the building.  The collector air flow path is horizontal across the full wall width.  There are vertical manifolds on the left and right sides.  This makes for a simple collector design with straight flow paths that are long enough for a good temperature rise, and that spread the airflow very evenly over the full absorber surface.
I think this is a good candidate for full wall collectors, and could be used for home or shop heating as a retrofit or in new construction.

The design of this collector is based on the TEA design just above.

Ken's DIY Solar Air Heating Collector -- Aluminum Soffit Absorber

All the how-to details...

Detailed how-to from Kenneth on a solar air heating collector that uses a flow through absorber made from vented aluminum soffit material.

The collector uses a metal frame and is glazed with twinwall polycarbonate glazing.


Al's hybrid solar air and water heating collector

Full Construction Details...

This is a nicely done and very interesting collector from Al.  It is primarily a fan forced air heating collector, but also includes a limited water heating capability to store some heat for night use.

A very nice looking collector.  Total cost for the 100 sqft collector was only $500.

Ron's Solar Air Heater

This is a solar air collector built to the ground rules of the book just above.

Ron even figured out a way to do this without cutting holes in the wall by making use of two existing basement windows.

The 60 sqft collector is durable metal and glass construction and was built at a very reasonable cost.

Jon's Horizontal, Screen Absorber Air Heating Collector
solar air heating collectorThis is a series of 6 short videos describing Jon's solar air heatingsolar air heating collector collector.  The collector uses a screen absorber and has a nice manifold arrangement that is aimed at  spreading the air uniformly across the collector absorber and avoiding low air circulation areas.  The circulation fan is  PV driven.  The collector also blends into the house very nicely. 
This design could be easily expanded for more heat if desired.
Solar Hot Air System Design,
Chuck Marken, Home Power Magazine issue 98, and 99

How to get articles from Home Power ...

A good two part Home Power article on designing and installing solar heating air collectors.
Solar air collectors offer a simple way to get free solar heat -- less complex and easier to build and install than solar water collectors.
60 sqft Active Wall Collector

Alain in France

This is a nice design for a wall mounted, 60 sqft, fan forced solar air collector.
Two Solar Air Heating Collectors with Absorbers from Aluminum Gutter Downspouts

Details here...


Two solar air heating collectors that use aluminum gutter downspouts as the absorber.  
One is a very low profile collector that minimizes visual impact, and the other a large collector that can be disassembled and removed for the summer. 
The aluminum downspout absorber provides an easy way to get both good flow distribution and lots of heat transfer area.
Glen and Ronny's Solar Heater Project


Homemade solar air collector using one continuous length of aluminum flex duct folded into a serpentine pattern.

A nice simple design.

Good pictures and details.

Greg's Pop-Can Solar Air Heating Collector


Full construction details on the collector...

This is Greg's very nicely done pop-can style solar air heating collector.


Greg does a very nice job on this, and provides 22 pages worth of construction detail....

Beer Can Solar Air Heating Collector


Original Hungarian version:

English Translation:


And another from Brian ...

This is a nicely done and well documented version of the alum beer can collector design -- similar to the CanSolar commercial collectors.


More about the builder and collector ...

A pretty good video on the CanSolar collector with some construction detail ...

Pop Can Collector from Sweden



A large, and very nicely built aluminum can collector from Sweden.   The builder provides a very detailed description of the construction with excellent pictures.  Lots of attention to detail and some new features.

The article is in Swedish, but the Google translation toolbar does a pretty good job, and the pictures are very good.

Brian's Pop Can Solar Heater


A nice set of picture plans for a 20 sqft pop can solar heater.

A couple notes: Don't use the polystyrene insulation shown it will melt if the collector stagnates.  Use polyisocyanurate (e.g Altals R-Board) -- most lumber yards carry some brand of polyiso.  A thermal snap switch makes an easier controller...

How to build cheap solar panel out of aluminum cans
This is a good and detailed description of a solar space heating collector built from aluminum soda pop cans.

A Design Challenge For Pop Can Collector Builders

downspout collector inletDesigning the supply and return plenums for pop can and downspout collectors so that they deliver the same airflow to each can row is challenging, and (I think) not well understood.

If you are building a pop can or downspout collector, how about taking the time to measure the flow in each can row and experimenting around with the plenum design to get to one that works well?  This is a very popular design, and working out a way to get the flow distribution right would help a lot of people.

Some thoughts on how to do this....
This $30 Solar Setup Heats a 30 X 40 Workshop for Five Hours or More Every Sunny Day, Editors

Finding Mother Earth News articles...



Mother Earth News article, Issue 48, Nov/Dec 1977 describes a very simple homemade collector for heating a shop.
The cost is kept down to almost nothing by using poly film glazing and some scrounged parts.

If you can scrounge the blower from an old furnace and find some used lumber, this collector probably takes the prize for lowest cost per square foot -- about 10 cents per sqft.  The payback period where I live is well under a month!

Building an inexpensive solar heating panel




Article from Mobile Home Repairs on building a wall mounted solar air collector with PV driven fan circulation.  Very complete How-To instructions.
Building and Installing a Solar Air Heater at Abundance Foundation,
Stephen Hren


This is a very nicely done and relatively easy to build solar air heating collector.  The collector fan is powered by a PV panel, which also acts as the controller.

Looks like they had a lot of fun building it!

The pdf file provides very clear instructions with lots of photos of the build and installation.

Greg's Solar Air Collector

Full Details ...


This is an easy and inexpensive to build solar air collector that can be built right onto a south wall.

It uses a small fan to circulate air through the collector.   Cost was about $2 per sqft.
Ganged Forced Air Solar Collectors

Pictures and Description ...


Nicely done set of home built solar air collectors with a well thought out way to join collectors.
Tim's Solar Air Heating Collector

Full Details ...

A nice, simple solar air heating collector.


Full Details ...

Solar Hot Air System Design
Chuck Marken

How to get articles from Home Power ...

Home Power magazine article, issue 98

Overview of solar air collector features, applications and pro/con.  Limited system design and sizing info.

Solar Energy Mobile Home Improvements,
Editors, 1985


 Finding Mother Earth News articles...

Mother Earth News Article, Issue 95 Sept/Oct 1985

Fairly detailed plans for a solar space heater intended for mobile homes (but probably adaptable to many situations).
Good construction diagrams.

This Old Trailer

Terry Ziegler

How to get articles from Home Power ...

Home Power Magazine article, issue 64

Very good article on adding solar space heating, water heating, a wind generator, and energy conservation features to a trailer. The solar air collector system is somewhat unique and well thought out.

28 Years of Tinkering

Steen Hansen Hviid

How to get articles from Home Power ...

Homepower Magazine article, issue 56

A report on a 70’s style active solar air collector system for a house that uses rock bin storage.  Some information on the design and construction of the system, and 30 years of experience living with the system, which is still doing well.  Also, some information on a PV and wind systems that were added later.

Experiments With Solar Air Collectors
Ralf Seip

How to get articles from Home Power ...


Home Power Magazine article, issue 72

Good detailed article on building a simple solar air collector.
Lots of data on construction and performance.

The Sol-Air Wall Mounted Air Heating Collector

Bill Kreamer,  Sol-Air Company

Download Plan pdf


Greg's detailed detailed accounting of building this Sol-Air collector with lots of pictures...

An easy to build, wall mounted solar air collector with forced air circulation.
The collector uses a flow through felt absorber to achieve high efficiency.
Greg provides a detailed description with lots of pictures on the construction of one of these Sol-Air collectors.

The combination of Bill's Kreamer's plans and Greg's pictures will make this collector construction a lot easier.
All the details...
Mike Smith's Solar Home -- 25 Years of Trouble Free Solar Heating

etails on the system...
25 year old solar heating systemThis is a super insulated house built in 1985 with a 360 sqft solar air heating collector with rock bin heat storage.

The system has been operating for 25 years with zero maintenance and is still going strong!

Details on the system...
Large Active Air Collector

Fitch Consulting...



Quite a bit of detail on a solar space heating system that uses a large active solar air collector, as well as evacuated tube collectors.  The system has saved $8500 since  since 1994, and provides about 60% of the house energy bill.
Solar Heating -- Three in One
David Sweetman

How to get articles from Home Power ...

Home Power Magazine article issue 101

Description of a solar thermal heating system in Nevada that provides some space heating, hot water heating, and spa.  Limited hands-on information.

Very large solar grain drying collector,
North Dakota State Univ -- Extension Service

Download the plan ... (pdf)


North Dakota State University -- Extension Service -- Plans download page ...



This is a very large (2000 sf!) and very cheap solar collector that is intended for grain drying.

It is not going to be of direct use to many people, but the design is very interesting and has features that might be useful in a large and cheap space heating collector.  The basic materials for this collector come in under $1 per sqft.  Its biggest problem for space heating would be that it is horizontal, but some elements of the unique design might be useful in a collector tilted for winter heat gain.

The Appalachian Solar Lumber Kiln,
Dennis Scanlin, Appalachian State University

Home Power Magazine, issue 63, Feb 1998

If the above link does not work, then here is How to get articles from Home Power ...

Note: I've included this wood drying kiln in this section because the collector design is very interesting and could be incorporated in a roof for space heating.
A well thought out design for a solar lumber drying kiln.  The article includes good design, construction, and performance detail.

The design uses a solar air heating collector with a flow through absorber.  The collector comprises the full south face of the kiln.  Air is circulated though the absorber with 3 12 VDC fans driven by a single PV panel.
(thanks to Loran for suggesting this article)
Looking for a good overwindow collector design...

an overwindow solar collectorThis is a first cut at finding a nice looking over window solar collector design that produces a worthwhile amount of home heating.

It has a ways to go, but maybe you have some suggestions to make it better? Lets hear from you.


Avoiding Odor Problems with Solar Air Heating Collectors...



Solar air heating collectors circulate room air through the collectors, so if materials used in the collector give off an odor when heated, the circulating air will carry the odor into the room.  Here is how to avoid odor problems ...
Low Thermal Mass Sunspaces for Home Space Heating (and many other things)
Low thermal mass sunspaces provide an exceptional combination of advantages:  very efficient space heating for the home they are attached to, added living space that can be used for a wide variety of purposes, a wide range of cost effective designs, and they can also look great (a plus for HOAs and spouses).

This section provides a design guide to explain what its all about, test data that documents their heating efficiency, and quite a few example low thermal mass sunspaces.

Design Guide for Low Thermal Mass Sunspaces,

This design guide covers low thermal mass sunspaces -- including:

  • What they are.
  • How and why they work well.
  • Covers the design rules for goes over the design rules.
  • Testing demonstrating the heat output and efficiency.
  • The multi-purpose space advantages and uses.
  • What they don't do well.
 Low Thermal Mass Sunspaces for Space heating

Transparent, Walk-In Enclosure Installed Along South Side of Existing House and Used to Heat the house,
William Shurcliff

Nick Pine usenet post on low thermal mass sunspaces...


low thermal mass sunspaceThe two articles listed to the left explain how low thermal mass sunspaces work, and why they are so effective for space heating.

In a nutshell, if your main goal for the sunspace is house space heating, you don't want to waste solar heat heating up mass out in the sunspace.

sunspace for space heating

sunspace heating performancesunspace temperaturesThis is a testing I did to measure the heating performance and efficiency of a low thermal mass sunspace for space heating. 

In addition, it provides temperature surveys of the space, thermal images, and some thoughts on designing for a combination of good space heating and a comfortable space to spend time in.

The sunspace performs very well as a space heater -- on par with high quality active collectors -- and you can read your paper and catch a few rays.

All the details...
Example Low Mass Sunspaces
Some examples of low thermal mass sunspaces that shows some of the huge range of  possibilities.
Mike's Low Thermal Mass, Multi Purpose Sunspace in the Colorado Mountains

Colorado low mass sunspaceThis is Mike's low thermal mass sunspace in Colorado.  It is used for a variety of purposes including heating the house, drying clothes, kids play room, drying food, and reading the paper.  In addition to all those uses, Mike is currently working on a way to integrate solar water heating into the sunspace.

An exceptional job of blending the added sunspace with the existing house. 
The variety of purposes that sunspaces can be put is what makes them exceptional -- drying clothes alone saves about 1200 KWH and 2000 lbs of CO2 a year.

Mike provides all the details on the design, build, and performance...
Nick Pine's Innovative Three Story Sunspace

All the details on Nick's sunspace...
innovative sunspaceThis is Nick's new and cutting edge three story sunspace. 

It includes a number of innovative features such as custom made DIY double glazing, an experimental mesh system to improve collection efficiency, and a unique heat distribution system.

All the details on Nick's sunspace...

Low Thermal Mass Sunspace in Minnesota,
William Sikora




Architect William Sikora describes his design for a modern and elegant sunspace for this Minnesota home.

The air distribution and control system is very simple, and designed to be maintained by the home owner with only simple tools.

Certainly a beautiful and cost effective addition to the home.

All the details on this modern, elegant sunspace...
Norman Saunders Cliff House

Cliff house by Norman Saunders (pdf)


The Cliff house designed by Norman Saunders uses a large, 2 story, low mass sunspace across the front of the house that provides 100% of the heating demand for the house all year.

The sunspace is coupled with heat storage systems in the attic and crawl space that allow the home to achieve 100% solar heating.
Instant Sunspaces  -- How cheap can a sunspace be?

Laren Corie
Download the Feb, 2005 issue


Ed's Zero Cost Sunspace ...

ESSN Journal, Feb, 2005

A good article by Laren Corie on how to build and experiment with inexpensive sunspaces.  The example used in the article cost a grand total of $22, and went together in a couple hours!

A free download.


Here is another very low cost (actually zero cost) sunspace done by Ed.   Details ...

This shows how inexpensive and easy it is to turn a porch into a sunspace that is pleasant to spend time in, and can supply some heat to the house.

Air based solar-thermal “Hot-Box” collector

Full details...


solar thermal hot box collectorMitch calls this a "Hot-Box" collector, but I think it could equally be called a mini-sunspace.

Very nicely built -- as Mitch says, its "wife approved".

Some performance estimates provided.

Note the use of the reflector to improve collection -- reflectors are particularly effective in that they increase collection area without increasing heat loss.
I would pass on the idea of adding rocks for heat storage for the reasons discussed above -- unless you have a way of insulating the glazing at night.
Heat from the Attic  -- This section covers various schemes from simple to involved for using the attic to harvest solar heat.
Using Attic Heat
Logged Attic Temperatures

Details ...



This page goes over some potential ways of using attic heat, including preheating water, space heating, a source for pre-heated dryer air, and pool heating.

It also provides long term plots of my attic temperature, which is probably typical of cold many cold northern US climates.  These give some feel for the potential.


Tim's Attic Hot Air for Space Heating Project

EcoRenovator Forum post with the details on Tim's design...

EcoRenovator Forum post with the details on the controller...
Tims heat from the attic systemThis is a project from Tim at the EcoRenovator Forum that simple blows hot air from the attic into the living space.
Tim used two bathroom vent blowers mounted up in the attic to blow hot air down a no longer in use chimney and into the kitchen.

A differential controller senses when the attic air is hotter than the house air and switches the blowers on.  A flapper prevents reverse flow.  Simple and effective.
Tim provides construction detail and some performance data.
Randy's Invisible Solar Attic Collector

Solar attic heaterRandy describes his simple system that uses the attic roof trusses and lower surface of the roof as a solar collector.  This simple system circulates livingattic heater room air through the collector and back down to the living room.  It is invisible from the street, so the HOA won't even know its there.
"Black Roof" Solar Attic Heater
From "Solar Air Heating Systems", Steve Kornher and Andy Zaugg

The Black Roof Collector



This is a very inexpensive system that uses your dark colored roof as a solar collector.  The cost is very low, and it can be installed with a weekends work.  It might supply about 15% of your heating needs.  It is not for all climates. 
This extracted from the book "Solar Air Heating Systems".
Build a Solar Attic,

This is a really interesting scheme by Rob to use the existing attic and roof for collection -- but still experimental -- so allow for some challenges if you go this way.


This is a very nice project to incorporate a solar heating collector into a home's basic roof structure.

Rob describes in detail the first stage of incorporating the collector glazing into his new roof. 
He will now experiment with various sort of collector designs behind the glazing.  Add a comment into his blog to encourage him to keep us up to date on how he is doing! 
(thanks to Erik for suggesting this link)
Greenward Ridge Vent Water Heating System


Article with a bit of detail...


A new idea for solar water heating.  An antifreeze fluid is circulated through  the attic ridge vent to pick up heat from the hot air exiting the ridge vent.  The fluid is routed through a heat exchanger that is embedded in a solar preheat water tank -- this preheats the water before it gets to the regular hot water tank.

more (including a diy alternative)...
(Thanks very much to Chris for finding this!)

Penthouse System Employing Stack of Water Filled Containers, A large Single Glazed Window, and A Collapsible 4 inch Thick Thermal Curtain...

Attic Penthouse Scheme...
And, a 2nd Penthouse Scheme...

The full book...
Shurcliff attic solar schemeA scheme from William Shurcliff's great book on innovative solar heating schemes that uses an attic "penthouse" for collecting and storing solar heat.
Solar Heat Storage in the Attic

Cliff House...
Solar storage in atticSome of the most successful solar heating designs use the attic space for heat storage using water filled containers.
This home by Norman Saunders is a classic good design that achieves 100% solar heating in a difficult climate.
Providing Fresh Ventilation Air   -- Heat Recovery Ventilators and Other Methods
For homes that have been sealed very well, some form of ventilation to bring in fresh air may be needed -- this section provides a couple ways to do this.
Note that most homes are not tight well enough for this to be a problem.
DIY Heat Recovery Ventilator...

DIY HRVThis is a set of plans published in the 80's for a Heat Recovery Ventilator made from sheets of Coroplast.
A Homemade Heat Recovery Ventilator (HRV),
David Meinert

Plans for homemade HRV... (Word Doc)
homemade HRVThis is a detailed set of plans for an HRV made from sheets of aluminum flashing.

It appears to be relatively straight forward to build, and that it is made from materials that should hold up well.

The writeup also includes some material on fans and blowers.

David tested the unit and got a heat recovery efficiency of 70% -- which is equivalent to commercial units.
Guy Marsden on Installing a Single Room Energy Recovery Vent...

Guy gives a very detailed account of installing one of the new room size Energy Recovery Ventilators that have become available at a somewhat reasonable price. And, also provides some measured performance and a mod that makes monitoring the ERV mode easier.

If you are not familar with Guy's site, have a look around -- many interesting projects.

Installing a Heat Recovery Ventilator (HRV)...

Installing HRVThis is a pretty detailed description of a DIY install of a Venmar HRV unit from the DIYChatroom site.
Book goes over HRV (and other) Heat Exchanger designs,
William Shurcliff 

Another entry on DIY HRV's from
air to air heat exchangers for house This 1980's book by William Shurcliff  covers the design of air to air heat exchangers for home use.

It also has a little material on a DIY design that uses sheets of polyethylene for the heat exchanger. I've excerpted these couple pages.

Reflectors to Improve Collector Performance
A section on reflector design, reflector performance, a reflector test rig, and examples of reflector use...

Reflectors offer a uniquely effective way to increase heat collected without increasing heat losses.

This section on reflectors provides: Reflector design tables, A simple earth-sun simulator you can use to test reflector designs, and many examples of effective use of reflectors.

See also the batch water heater section of this page for some more examples of reflectors used to improve collector performance.

An Easy to Build Earth-Sun Simulator for Optimizing Reflectors and Shadow Studies...

Earth sun simulator for reflector designThis is an earth-sun simulator you can build to test reflector designs or to understand sun and shade patterns on anything you can build a model of.

It allows you to see the sun and shadows for any location on the earth and any season and for any time of day. By rotating the turntable you can quickly play the sun over your model for a full day and see the sun and shade patterns. You can take readings on the model with a light meter and get a quantitative idea how much (for example) a reflector is increasing radiation.

Geothermal Heating
Geothermal heating uses heat directly from the ground for space or water heating -- e.g. capturing heat from a hot spring.
Geothermal Hot Tubing

Michael Hackleman

How to get articles from Home Power ...

Home Power Magazine Article, Issue 109

Article on using a geothermal hot spring as a heating source for hot tub and space heating.  The system uses a custom built heat exchanger made from copper pipe coils to transfer heat from the hot spring.

Geo-Heat Center

Technical (and not so technical) publications on Geothermal heating and heat pumps.

The Geo-Heat Center at the Oregon Institute of Technology provides a lot of information on Geothermal heating and on Geothermal Heat Pumps.
Geothermal Heat Pumps

DIY Geothermal Heat Pump + PV System - No Heat Bills!...


diy gshp plus pv installationThis is Jerry's DIY installation of a 5KW PV array AND a Ground Source Heat Pump system.

This system is a difficult and time consuming project, but ends up providing all of the energy for space heating and cooling as well as water heating, and very low emissions. All with a relatively short payback period.

A good detailed description of the design and build of this system is provided in a 26 page pdf.


EERE info on Geothermal Heat Pumps

Heat pumps come in a dazzling array of variations -- here is a place to start:

EERE on Geothermal Heat Pumps

The EERE provides some good basic information on both geothermal and air source heat pumps. 

When you look at heat pump "efficiencies" of 300% and more, please bear in mind that this does not include the inefficiency of the 30% efficient fossil fueled power plant where the electricity to run the heat pump is likely generated.  From the earth's point of view, heat pumps may not be the best pollution solution.

Other approaches such as improvements to the home's thermal envelope, a more efficient furnace, and solar heating, or a heat pump powered by PV (as in the system just above) should be considered as alternatives.

Builder Guide to Geothermal Heat Pumps

Bruce Harley

Builder's Guide to GeoThermal.pdf


Guide to planning, installing and maintaining ground source heat pumps.
Earth Energy System -- A Buyers Guide

Natural Resources Canada


A good 44 page guide on ground source heat pumps from Natural Resources Canada. 
Heat From The Earth -- A Heat Pump Primer
John Lynch

How to get articles from Home Power ...

Home Power magazine article, issue 98

A good overview of ground source heat pumps with some limited sizing and design information.

Green Building Talk ...
Provides some useful links on GSHP's that seems to be fairly even handed.  Much of the material out there on GSHPs tends to be on the optimistic (sometimes wildly optimistic) side.
Are electrically powered heat pumps good?


Do geothermal heat pumps really reduce greenhouse gases compared to a modern gas furnace?
Are there better options?
Measured performance of Geothermal Heat Pumps in actual homes

Residential Ground-Source Heat Pumps: In-Field System Performance and Energy Modeling, Puttagunta, Aldrich, Owens, amd Mantha, 2010 ...

Measured Performance of Five Residential Geothermal Systems, NREL ...



The first report is a recent report on actual performance of 3 modern residential heat pumps.

The 2nd (older) report provides actual measured performance data for 5 geothermal heat pumps installed in residences in Ohio.
Covers heating, cooling and water heating performance, including measured COP's.  The systems were carefully instrumented -- a lot of useful and interesting data is provided.

Both reports show substantial differences between brochure COPs and measured COPs.  The first report also has some very interesting observations on desuperheaters and how they should installed for good efficiency.
Some Vertical Well Geothermal Heat Pump Construction Pictures




Some pictures on installing the vertical ground loops in wells for a geothermal heat pump system, and some of the equipment room installation.
True DIY Heat Pump Projects

The Homemade Heat Pump Manifesto...


Multi part EcoRenovator blog on DIY GSHP...


These are two long (as in 22 pages) posts on completely DIY ground source heat pump projects.  The heat pump units are made from salvaged AC units.  The projects even include homemade rigs to drill the boreholes for the geo exchange loops.  Very good detail.

The EcoRenovator site and forum have some fascinating, unusual, and hard core DIY energy projects.

GS2000 Heat Pump Ground Loop Sizing Software


GS2000 is a free program offered by Natural Resources Canada to size the ground loop for ground source heat pumps.

It handles a wide variety of loop types and does horizontal loops as well as vertical boreholes. 
The inputs require a bit of work to develop, but given that improperly sized ground loops is a major cause of disappointing GSHP performance, its probably worth the effort.

More sources of GSHP information...

The Heatpump Center...

Waterfurnace (a GSHP manufacturer)....
Heat Distribution
This section covers hardware and techniques for distributing the heat from a solar heating system to a house or other building.
Design of Home Heat Distribution Systems for Solar Heating...

This is the page that covers design of the heat distribution system for our $2K Solar Space + DHW project.  Its general enough to apply to a lot of solar heating projects, and goes over the common ways of distributing heat for a solar system.

Please let me know if I missed and good schemes for distributing solar heat.
Radiant Floor Heat Distribution -- References

Solar Shed radiant floor system...

Radiant Floor Company...

Radiantec Company...

RadiantWorks from ...  (radiant floor design software)

Radiant (hydronic) floors are ideal for distributing solar heat because the operate a low temperatures, which solar systems produce more efficiently.
Hydronic Baseboard Heaters

Heat output from baseboard heaters at low temperatures...

Here is similar data for cast iron radiators...
(thanks to Tom for finding this)

Similar for modern radiators...


Conventional hot water baseboard heaters can be used to distribute heat from solar systems.  Typically solar systems produce lower temperatures than boilers, so more baseboard heater length is needed for a given heat output.  The link to the left gives heat output for SlantFin brand baseboard heaters at low temperatures.
Quite often, all that is needed is enough baseboard to distribute the collected solar heat for one sunny day, which can be quite reasonable.
Heating Edge Low Temperature Baseboard
solar baseboardThis product provides more heat per foot of baseboard at a given temperature than others, so it may work well for low temperature water applications like solar heating.
Hydronic Wall Radiator


This is a very nicely done built in hydronic wall radiator.
It works in the same way as a radiant floor, but the PEX tubes are run behind the wall sheetrock instead of under the finished floor.

Shawn describes this in a blog post on his Green Gate Guest House project blog.
Shawn estimates about 35 to 40 BTU/sqft output with 115F water.

PEX Coil Radiator This is a radiator that Richard Heiliger made from PEX tubing.  Hot water is pumped through it, and it radiates heat to the room.

It can be covered with a cloth screen for aesthetics.  PEX tubing can also be embedded in a wall behind sheetrock.


A large wall radiator project


This is a detailed description of a large wall radiator.  In this case, the builder filled in the area that the wall tubes occupy with plaster --presumably to improve heat transfer and increase thermal mass.
This is in French.  If you are French impaired (like me), the pictures are very good, and the Google translating tool does a pretty good job.

(Thanks to Walter for sending the links to these wall radiators)

Solar Heating By Wall Heater


This is another wall radiator with a good set of pictures -- the one just above is based on this one.

This one is also in French.  If you are French impaired Google translator and the good pictures are your friends.


Homemade Pipe Radiator These pictures show a radiator that is used to heat the visitors center in Dawson City, Yukon Territory -- according to the staff it does an outstanding job.

More pictures...

Water to Air Heat Exchangers



A number of suppliers make water to air heat exchangers that can be inserted in an existing hot air heating system to add solar heat.

Two example suppliers listed to left.

From the MagicAire specs, it looks like a 17 by 22 inch, 2 row unit, at 900 cfm airflow and 4 gpm water flow with a water temp of 120F would provide about 24,000 BTU per hour. 

Typical performance for a standard sort of hot water to air coil heat exchanger...

Storage Tank Radiator The thermal storage tank that stores heat for a solar heating system could be located in the living space, and act as a radiator to heat the living space.  Some form of movable insulation could be used to regulate heat output.  This sounds a bit primitive, but I suspect it would actually work quite well -- especially in cases where solar heat is supplemental to other heating (as it usually is).

Air Floor Construction for Auxiliary and Solar Convective Heat Storage and Distribution, Bill Chaleff, A.I.A., LEED A.P.

Article on construction of the Air Floor ...

Pictures of Air Floor construction ...

Bill Chaleff's blog...

solar heat distribution air floorThis is a nice simple scheme for new construction to distribute the heat from solar heated air to a living space.
The solar heated air is distributed under a concrete slab using corrugated steel decking to provide closely spaced heat distribution "ducts".  The ducts are all feed by a V shaped plenum channel that is formed right in the slab.
The article covers the pros and cons, but it seems to me that one good pro is that there is some lag between the solar air heating the floor and the release of the heat to the room, so, less chance of overheating the room in the afternoon.
Other Radiant Air Floor Options


Kachadorian hollow concrete block solar air floor...
Good excerpt from Google Books ...

Another approach...
airfloorPicture to left is  a commercial product called AirFloor that is normally used with a forced air furance, but could be used with solar heated air.

Picture to right is from James Kachadorian's book "The Passive Solar House"
Low-Cost Active Heat Storage,
Nathan Hurst and Paul Harrison,
ReNew Issue 100

Low-Cost Active Heat Storage pdf ....

The article describes a way to use a car radiator and water tank as an inexpensive way to  store heat from a greenhouse.

In most cases, when a greenhouse or sunspace heat is used to heat an attached house, hot air from the GH is blown into the house for immediate use.  This paper shows a simple way to store GH heat for use later.

This technique can be used for any water to air or air to water heat distribution situation -- e.g. plumb hot water from a solar heated storage tank to the radiator located in the space to be heated.
Car radiators turn out to be very effective water to air heat exchangers and can be had for a low price.
(thanks to Nathan for making this available)

Water to Water Heat Exchanger from PEX Coil



This is a good job of forming a 300 ft coil of 1 inch diameter PEX into a coil style heat exchanger with very uniform spacing around each coil of the PEX.



Heat Distribution from Solar Air Heating Collectors Often the heat air from a solar air heating collector can just be "dumped" directly into the living space.  If the air does not get distributed well enough, a slow moving ceiling can can be used to distribute the air.

This is one of the nice things about using air heating collectors -- the distribution can usually be quite simple.

A blower and ducts can also be used to distribute the hot air from solar air heating collectors.

Insulating Underground Pipes

See the Components Page->Pipe Insulation for info on above ground and below ground pipe insulation.
Steve Baer, Zomeworks Corporation

Reflector/Shades paper... (pdf)



A good paper by Steve Baer reviewing the use of seasonally moveable reflectors to increase solar heat gain in the winter, and reduce unwanted heat gain in the summer.
A nice mix of solar physics and practical how-to that Steve has gained in the building of many of these types of reflector systems over the years.
Keeping Snow Off Collectors
Snow accumulation on collectors In some areas, snow accumulating on collectors can be a problem.  Evacuated tube collectors tend to be worse in this regard because the snow is slow to melt off,  but, it can be a problem on any collector. 
Usual solutions include:

- Steeper tilt to shed show
- Locating panels where they can be cleaned with a long handle brush or "roof rake"
- Locating collectors on the ground where they are easily cleaned.

It should be noted that in most areas, snow accumulation is not really a problem.

Rain X to keep collectors snow free?



Chad suggests trying Rain X to keep collectors free of snow/ice.
Sounds promising to me.


Avalanche Roof Rake



Jeff reported have good luck with removing snow from roof mounted collectors with this version of a roof rake.

This version has wheels, a snow cutting blade, and trails a slippery "tail" that the snow can slide down on.
This may too rough a tool for evacuated tube collectors?

Self Cleaning Solar Collectors


This is an innovative solution to snow accumulation in cases where dead airflow areas cause snow accumulation. 

The vane added to the top of the panel directs wind flow into the dead spots.

Solar Space Heating Components

Information on pumps, tanks, heat exchangers, controllers, ...


Collector Glazing Materials
Comparison of Solar Collector Glazing Materials...



A comparison of glass, corrugated polycarbonate, sheet polycarbonate, and other potential glazing materials for DIY solar collectors.
Other Renewable Energy Heating -- Compost, Biofuels, ...

Heating with compost...

Several schemes for using the heat generated by the composting process for space heating or water heating or greenhouse heating.
Heating with biofuels ... Many schemes for using biofuels of all types for space and water heating.