I am currently trying to set up and install a solar collector system to provide radiant floor heating for my shop and the basement of my house. I thought I was on the right track but became aware that the Contractor I was working with has a number of suspect instalations that are in court.
I am looking for a solar / radiant heating consultant or contractor with experience and can back it up with references/referals.
The system is 8 – flat panels heating a 3000 gallon underground cistern. Latitude 56 degrees North. Heating a total of 2300+ sq ft.
If anyone can point me in the right direction it would be appreciated.
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Martin
My location is Peace River, Alberta, Canada
Latitude ~ 56.225 N : Longitude ~117.300 W
Thanks
Big Al,
Here's someone you might contact:
Jorg Ostrowski
Alberta Sustainable Home
9211 Scurfield Dr. NW
Calgary, Alberta T3L 1V9
Canada
403-239-1882
Fax: 403-547-2671
http://www.ecobuildings.net
[email protected]
If Mr. Ostrowski can't help you, he may be able to recommend a consultant who can.
Thanks Martin
we did a lot of solar heating in the '70's & '80's
tried water collectors , but they were too expensive and too subject to leaking
ended up with hot air collectors.... some with rock storage.... some with direct dump to the interior... some with radiant floor heating
...the radiant floor heating used "Air-floor" steel forms.... pretty neat... i think the technology dates from the '20's
and the concept comes from the romans
http://www.airfloor.com/
anyways... the collectors involve a base of Thermoply ( TM )
a double 2x3 maze.... a 1/3 hp blower
galvanized absorber plate... and single glazed low iron glass.... typically 4x10
the radiant floor system is still running in a commercial condo downtown since '85
and our house is still being heated with a 10 x 36 array , since '86.... same blower.... zero maintenance in both cases
I've heard nothing but good things about Jorg. A friend of mine who knows him thinks he's a genius.
won't work you are so under sized for that far north
Solarvet
So How do I calculate an appropriate size of the system?
WHo can I contact that will help me out?
Thanks
Sizing solar heat for northern location.
Doing it entirely solar is going to be tough.
Sunlight at the equater at high noon runs about 1200 W/m2.
At noon in Peace River on the winter solstice, figure on about 500 W/m2, and that is at right angles to the sun.
Given that the sun is only 10 degrees above the horizon (90 - Latitude - axial tilt of earth = 90 - 56 - 23)
So you only get 500W for maybe 4 hours. Call it 2000 watt hours/square meter.
Suppose your shop is 2000 square feet, has 12 foot walls and is 40 x 50 feet. Insulate the roof to R50 and the walls to R30.
Roof heat loss = 2000/50 = 40 BTU/degree/hour
Wall heat loss = 180 x 12 = 2160 sqaure feet. divide by 30 = 72 BTU/degree/hour.
Bitter winter day. -40 outside, 60 F inside. = 100 F degree temperature differential.
72+40 = 112. times 100 degrees = 11200 BTU/hour. This ignores fresh air, leaks around doors etc. Realistically, double that.
Call it 20,000 BTU per hour.
= 480,000 BTU/day
Now, a watt hour is about 3.4 BTU. So dividing 480,000 by 3.4 = 140,000 watt hours, or 140 kilowatt hours.
So by this calc, you need about 70 square meters of collector surface -- about 700 square feet.
Worst case of coldest day and shortest day.
Expensive.
However there's a better way to do it.
Your south wall is 50 feet x 12 feet = 600 square feet. Strip the sideing off it. Put tarpaper on it, and another layer of 2x4 studding on it. Cover in horticultural grade clear poly ethelene. Put a second layer of 2x2 over this, running horizontally first on 2 foot spacing, then filling in beween on the joists. Add a second layer of poly. Fasten with battens. The poly will last about 3-6 years so you will be redoing this now and then.
The top ends of the 2x4's don't run all the way to the roof. Periodically you put a hole in the insulated wall, and mount a fan there. Similarly at the bottom end there is a way for cold floor air to enter the bottom of the sun cavity.
Whenever the sun shines, the air in the cavity gets hot. When the temp in the cavity is higher than the floor temp, the fans come on. Article in Mother Earth News about a guy in Montana who did this. It's not a complete answer -- his shop was workable from about 10 a.m. to about 4 p.m. in winter.
Thermostats can be salvaged out of old furnaces. So can the fans.
Method two.
Build a greenhouse extending teh end of the shop. In the winter, (no one uses a greenhouse as a greenhouse in the winter) hang a sheet of black plastic from the peak inside so all that low running sunlight hits the black plastic.
Put a big fan connecting the peak of the greenhouse with the shop, and open the door between the two.
In February, partition the greenhouse. Use one part for raising plants to sell, use yourself, use the rest for heating the shop. As the season gets milder, and your shop needs decrease, the partition moves and your plants get transplanted to bigger containers. At night, the warm mass of the shop can keep the plants from freezing.
Method three. Put in a big wood stove and be done with it.
Hi,
This is a method to use to estimate the solar fraction you can get based on heat loss, collector area, location etc.
It takes a bit of work to go through, but nothing difficult:
http://www.builditsolar.com/References/HowMuch/HowMuch.htm
I can tell you up front that 100% solar heated homes or shops are very unusual. It takes a very very good thermal envelope coupled with a lot of collector area coupled with a descent sun. Its better (Ithink) to think of solar as a way to cut your heat bill, and it can be quite effective at that -- but going 100% solar with no backup conventional heat is very hard.
Also agee with Mike that for many applications solar air heating collectors are simpler and cheaper. They don't easily provide for storing heat, but for a typically insulated building in a cold climate with a reasonable (or even pretty large) amount of collector, the building thermal mass will store enough heat. As an example, this is my $350, 160 sqft solar air heating shop heater: http://www.builditsolar.com/Projects/SpaceHeating/solar_barn_project.htm
Gary