11/06

when i tell people i do solar thermal a living they usually start talking about solar electric with me. there not the same. solar electric or pv or photovoltaics is the new trend. its been around for a while, but not a residential scale. solar thermal however, has been around since the late 70s early 80s when carter was giving tax breaks for these systems to offset gas usage. its all about heating up water with the sun. theres a lot of variations, but ill stick to my drainback system, which keeps my gas off most of the year, this is about a $16,000 system i made for $4,000 myself. it saves me about $500 a year



the beauty of copper is in its heat exchange capabilities, being such a good conductor they are great fluid heat exchangers


1 of those 100 foot 1 inch copper coils is for my domestic hot water. before my well water goes to the water heater it passes through this coil to raise the temp from 55 to anywhere from 100 to 170, depending on the tank temperature


this tank, the one i made with wood and an epdm bladder. its insulated with 3" foam board, uses radient floor tubing for hanging the coils and various ports made from bulkheads. cold water gets pulled out of the bottom of the tank and pumps through the panels on the roof as long as the panels are 16 degrees hotter than the tank. when the differential is not met, the water drains back into this tank. thats how it gets 700 gallons up to 180 degrees


the bulkheads are real important part of this project. you have to recycle these bad boys every time you can


so the 150 degree tank water gets pumped through this coil in my forced air furnace when my thermostat calls for heat and my solar tank is hot enough (120). my blower turns on in the furnace as well as a pump from the solar tank. the gas doesnt turn on and the house is heated with hot water


skills to make this thing include carpentry, plumbing, mechanical and elecrical


heres what the tank looks like now, a big shelf


heres the thermal panels on the roof. they are on a steep angle to maximize the low winter sun when the heat is needed the most and to get the snow off


see how the panels are sloped? thats so i get drainback, or all the water back in the tank when the system isnt running. otherwise that still water would freeze and break the panels. this is also my pre photovoltaic roof


next thing i do is tear the hip out of my roof design


these roofers sucked


eventually i got a new roof without the hip in the front. that pipe is one of my supplys to the panels (i have 2, 1 for each array)


once the pv panels were up i could put the thermal ones back on. i attached unistrut with spacers (to keep water from damnin up) to my rafters every 4 feet. then the brackets for the panels could be mounted


my approach was to have all the skaters that come over to my house help me get them up and down. it worked great, its really easy to get 8 dudes to help move 10 panels no matter how drunk. once they were in this line on the backside of the roof i could put them up by myself. the roller in the previous picture helped alot


there they are, solar electric and solar thermal panels taking advantage of our massive supply of sun


the hips gone so i could have more solar space on the roof


this is that other coil that was in my drainback tank.
with a crazy surgery i took it out cuz it wasnt being used
(it was for a future idea)


i had an idea to use a burn barrel to heat my solar tank
in the basement. essentially when its cold and cloudy
for a couple days i can heat my solar tank with a fire
then i can heat my house with that stored hot water


are you two ready to get married?


ideally you want the cold water to come in at the top of the coil so it gradually
gets hotter as it gets down closer to the fire and out the bottom


the coil sits on some unistrut above the fire. as the water passs through the coil it heats up


its all set on the drainback principal like the solar above. you better have all those pipes sloped at least 1/4 inch per foot so you dont have a freeze break


the fire department has been to my house a couple of times. it sucks they waste their gas to come see me, and so far everythings been legal and no problems