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Solar Hot Water Kits

Check With Local Installers

If you are interested in installing a solar water heating system, one thing you should do is talk to any local businesses that do this kind of work, and see if they will  work with you on providing a kit of parts at a good price.   In our area, one of the very good local solar installers is happy to work with DIYers, and provides good prices.

List of Kits

AmericanSolarTechnics Closed Loop Solar Water Heating System Specifically Designed for DIY Attractive price
www.americansolartechnics.com
Description: This is a new solar water heating system kit that was designed from the ground up of do-it-yourself installations.  The collectors are small and easy to handle and install.  It uses a PV powered pump, so no 120VAC wiring is required to install the system. The total price for a kit including nearly everything needed is $2750 -- the lowest of any of the kits on this page. Freeze protection is provided by anti-freeze -- which is actually included in the kit. Tom Gocze who founded AmericaSolarTechnics is a long time friend of BuildItSolar and has been producing solar products for decades.  This is his cut at a system that gets the cost of a solar water heating system down to a level that offers a good return on your investment.

Solar Heat Exchanger Manufacturing
Simple Drainback Systems
www.solarheatexchangemanufacturing.com
Description: This is a unique design in which the single large drain back tank is used for heat storage only.  The pump circulates tank water through the collectors when there is sun, and the collector water drains back to the tank at night.  Incoming potable water makes  a single  pass through a finned copper coil heat exchanger that is immersed in the drainback tank.   The design ends up being very similar to our $1K homemade system.  I suppose I'm prejudiced, but I like the simplicity and low part count of this design.

The next three entries are packaged systems from AET -- AET provides a helpful page that summaries the types of systems they offer...

altE Store
Alternate Energy Technologies LLC Closed Loop Solar Hot water Systems Drainback Freeze Protection & AC Backup
www.altestore.com/store/Packaged-Systems/Climate-freezes-Closed-Loop-Systems/...
Description: This is a traditional drainback solar water heating system.  The system uses a separate 10 gallon drainback tank that the collectors drain back to for freeze protection.   When sun is on the collector, a  pump circulates water through the collector, then through a heat exchanger wrapped around the solar storage tank, heating water in the tank.  When sun goes off the collector, the collector water drains back to the 10 gallon drainback tank for freeze protection.

altE Store
Alternate Energy Technologies LLC Closed Loop Solar Hot water Systems AC or PV Powered Systems
www.altestore.com/store/Packaged-Systems/Climate-freezes-Closed-Loop...
Description: This is a traditional closed loop system that uses antifreeze for freeze protection.  When the sun is out, the pump circulates antifreeze through the collectors and then to a heat exchanger that wraps the solar storage tank.  Various tank and collector sizes are offered. A PV powered option is also offered.

altE Store
ALTERNATE ENERGY TECHNOLOGIES LLC OPEN LOOP SOLAR HOT WATER SYSTEM
www.altestore.com/store/Packaged-Systems/Climates-are-mild-Open-Loop...
Description: This is an open loop system in which potable water from the solar storage tank is circulated directly through the collectors.   It is a simple and cheaper system with fewer parts, but is for non-freezing climates only. Very limited freeze protection is provided by circulating tank fluid through the collectors when freezing temperatures are reached, and by A dribble valve. A variation in with PV powered pumps is also offered for essentially the same price.

Heliatos
Heliatos Solar Water Heating System Kit
shop.heliatos.com/main.sc
Description: This is a very simple and easy to install system that uses a set of 2 by 2 ft collectors that hook together easily. It connects to your existing hot water heater via a provided fitting that connects to the hot water tank in place of the boiler drain that is on the tank now. A small, PV powered pump is used to circulated water directly from the your hot water tank, through the collector, and back to the hot water tank.  The PV panel acts as the controller, so there is no separate controller, and the only wiring is to connect the PV panel to the pump. Seems like this is about as simple as a system can get. Cautions might be:  NO FREEZE PROTECTION -- this is for non-freezing climates only, the entire system runs under full house water pressure, long term scaling may be an issue if your water has high mineral content, efficiency of using your existing hot water tank. You can buy kits with up to 8 panels, which would provide the equivalent of one 4 by 8 ft collector -- a small system.

Rheem
Solaraide Passive Solar System Series
www.rheem.com/product/Solar-Water-Heaters-Solaraide-Passive-Solar-System
Description: A roof mounted thermosyphon integrated tank and collector unit.  Simple thermosyphon system means that no pump or controller are needed.  Not for freezing climates. Its important to read the manual carefully before ordering, as there are some limitations that will effect some installations. A backup heating element is included in tank -- requires 240VAC circuit to roof. Tank and collector mount on roof -- weight needs to be considered.

Rheem
Solpak closed loop systems
www.rheem.com/product/solar-water-heaters-solpak
Description: This is a traditional closed loop system.  Antifreeze is pumped through the collectors and then to a double wall heat exchanger in a solar heated water storage tank.  Several sizes of collectors and tanks are offered. A number of variations in collector arrangements and tanks are offered.

Radiantec
Radiantec Solar Packages
www.radiantsolar.com/solar_packages_and_pricing.php#solar_packages
Description: Radiantec is known more for solar space heating than for solar water heating, but they do offer some solar water heating packages. This is a closed loop system with antifreeze for freeze protection.  The systems have options for heating things other than domestic water (floors, spas, heat dump,...) Radiantec has a reputation for being interested in DIY business and providing support to DIY installations.

Solar Direct
AET ProPack Solar
http://shop.solardirect.com/product_info.php?manufacturers_id=&products_id=1080
Description: This is a drainback system that combines the drainback tank, two pumps, and heat exchanger into a Energy Labs "ProPak" unit (#3 on diagram to right).  A heat exchanger and pump in the ProPak transfer heat from the drainback tank to a separate solar storage tank. I think that when the system is bought as a kit, the tank and ProPak unit come pre-plumbed and wired. This looks like a relatively straight forward system to install as some of the work has been done with the pre plumbing/wiring of the ProPak to tank.  PEX can be used for most of the plumbing. The pumps in the ProPak are sized for a large collector area and up to a 35 ft lift from tank to collectors -- so, they will be bigger than ideal for systems with smaller collector areas and lower lifts.

SunEarth

SunEarth offers several solar water heating systems -- including closed loop, drainback, thermosyphon, and batch.  I was not able to find a place that I could buy these systems, so have decided not to put any detail in for now. 

Parts Usually Not Provided in Kits

The following stuff is often not provided.

- pipe, fittings and insulation for plumbing runs from tank to collector

- Extra wire for collector temperature sensor

- Roof penetration/sealing materials

- pipe and valving for connecting the solar heated tank into your existing hot water tank.

- Thermometers and gages needed to monitor temperatures, pressures, and flows (sometimes provided, but often not)

- Wiring to provide outlets for pumps and controls.

- Collector mounting hardware

Other Approaches

Here is a quick review of other ways to get to a solar water heating system.

Build from scratch

Of course you can build the whole system from scratch.  This is easier than it sounds, and its possible to get a very good and reliable system that performs better than most commercial systems for about $1000.  The system can be sized to your exact needs, and it is easy and cheap to oversize it a bit to make sure you get a good solar fraction.  

If you go this route, you will not qualify for the federal tax credit, but you may still qualify for state or other rebates.  For example, my system cost $1000 out of pocket, and qualified for the Montana $500 tax credit -- so, the net cost was only $500.

See the Solar Water Heating page for many examples...

Build from scratch, but use commercial collectors

In this approach, you build the system yourself as in the "Build from scratch" case, but instead of making collectors, you buy commercial collectors that are SRCC certified.  If you do this, you will be eligible for the federal 30% tax credit.

Make your own kit

There is nothing magic about the kits listed above -- they consist of a selection of standard, off the the shelf parts.  You can put together your own selection of parts to make up your own "kit".  This may have some advantages in terms of finding good prices and/or avoiding some shipping.  But, on this approach,  you take on the responsibility for making sure the set of components you pick is compatible with each other and with your site.  There is enough information on Build-It-Solar to allow you to do a good job on the design -- I'd start in the Basics section of the Solar Water Heating page...

The $1K solar water heater kit

This is a kit of parts I selected that you can buy off the shelf:

- Collector --$1070 --  buy one 4 ft by 10 ft flat plate collector from any number of good brand (heliodyne, AET, SunEarth, ...)
   This would be something to shop around for locally and online. 
   Make sure the collector is compatible with   a drain back system -- ie that it uses the header and risers design.

- Tank     American Solartechnics Softank  -- $485 --  120 gallon, insulated Softank

- Heat Exchanger  -- $120  -- 300 ft coil of 3/4 PEX

- Controller  -- SHEM 32  differential controller  $100 (or one of the several here... for even less)

- Pump -- Grundfos 15-58  -- $70

Total about $1845

So, this would be a system like the kits listed above where you install off the shelf components, and do not have to make the collector or tank yourself.

This system is simple and would be relatively easy to install using the $1k instructions...   It would be a reliable, four season, cold climate system with good performance.  And, it would qualify for the federal 30% tax credit.

On the downside, you would have to deal with multiple suppliers and shipping.

I picked one set of components. There are many possibilities.  Do some shopping around.  Email me if you have questions or ideas.

Another interesting possibility would be to use an unglazed pool heating collector instead of the traditional glazed copper collector -- this would make the system somewhat like the Fafco Sungrabber system described just below (only better).

The Fafco/Sungrabber System

Fafco makes a solar water heating system based on their un-glazed pool heating collectors -- described to some extent here...

It seems like this system would be ideal for DIY installation -- its a simple drainback system with few components that all ships in a small box.  But, unfortunately they do not offer it for DIY installation -- you might bug them about that!

There are dealers that install the system, and you might be able to work something out with them to sell the package to you without installation.

May be available here?  http://www.siliconsolar.com/hot2o-solar-hot-water-heater-kit--for-electric-heaters-p-17967.html

Gary February 21, 2012, February 22, 2012