Need help with options on solar heat

[d3ejmz]

Hi there,

Been reading the group for a while. George at utterpower turned me on to it.

I have a dilemma.

I have 8 4x8 solar panels of unknown make, but they appear to be of high quality.

I also have a building of about 12,000 sq. ft. that I want to heat with said panels, and provide DHW as well.

The main part of the building is a long section 100ft x 60ft with the 100 feet facing south Woohoo!

We are heating a slab for this section and probably will want to use hot-water modines for the other section of the building.

My questions are:

1. how do i wade through the morass of information concerning circulators, thermostats, mixing valves, storage tanks, heat exchangers, etc? I mean is there a repository of info concerning what people have found to work and what does not work?
   
2. has anyone done something like this and would care to share their experience/advice?
   
   

Thanks very much

Jim

[BrianK]

If I can help u i will i am no genius about things, but I got 2 4x8 solar waterheating panels with all the parts. I also have the instruction book that came with it. So if u would like u could e-mail me mrohiofats(at)aol.com or i can try to post info here.

 .

[d3ejmz]

Thanks! I'll mail you off-list...

Jim

[GaryGary]

Hi,

Probably the best way to use water heated by solar collectors for space heating is with a radiant floor (ie slab with embedded PEX tubing).  This allows you to heat with water that is relatively cool (say compared to radiators) -- solar panels are  more efficient (produce more heat) when used at low temperatures.  

These are some good links on designing and building a solar radiant floor:

http://www.builditsolar.com/Projects/SpaceHeating/Space_Heating.htm#Active

The very first article by Guy Marsden is a very detailed description of his solar radiant floor system.  The HouseNeeds site has a variety of radiant floor solar heating diagrams with various kinds of backup heat.

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It sounds like you are thinking of mounting the collectors on the south wall?

The vertical wall mount is good for winter space heating, because the sun is low.  If your climate is such that there is frequently snow on the ground, then you get an extra bonus with the wall mount from the reflection off the snow.  For year round heating of water for showers etc., mounting the collectors at an tilt angle about equal to your latitude provides the best year round performance.  But, with that much collector area, you would still get a lot of hot water in the summer with the panels mounted vertially -- just make sure the roof overhang does not shade the panels in the summer.

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You have lots and lots of square footage, and unless you live in a mild climate the 8 collectors are not likely to be enough to provide a large fraction of your heat.  Have you thought about using some of that south wall for some simple thermosyphon air collectors?  These are cheap (as little as $2 persqft), and provide a lot of heat.

This is the one I built for my shop:

http://www.builditsolar.com/Projects/SpaceHeating/solar_barn_project.htm

You can also incoroporate direct gain windows in the south wall.  These would be just as effective in collecting solar energy as commercial collectors are.  But, they should have some form of insulation at night, or the losses are large.  The nice thing about the windows is that you get lots of light.  There are a few on my space heating page:

http://www.builditsolar.com/Projects/SpaceHeating/Space_Heating.htm

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If you want to check out those panels before you install them, here are some things to look for:

http://www.builditsolar.com/Projects/WaterHeating/UsedCollectors.htm

Gary

[d3ejmz]

Thanks for your response, Gary.

   Yes, indeed we are planning a radiant floor with PEX tubing. We've been doing these for years and it has ALWAYS saved us big. The only reason we aren't putting  radiant floors in the front section of the building is that there is a large basement underneath and wood floors over that. Radiant floors are a future project due to cost. For the pressroom, they are a necessity. I would never try to run a print shop on the ground floor of any building unless it had a radiant floor.

   We are planning to mount the panels on the roof, which is about a 2:1 pitch. Thanks again for the links and helpful input.

Sincerely,

Jim Farley

[d3ejmz]

OOps I was mistaken about the size of the building...

it's 45x200 on the main section, not 60x100 as i said before. somehow i got two of our buildings mixed up in my head. we have a woodshop that is 60x100..

Jim