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Comment by Bob Campbell on May 12, 2012 at 9:03am

We are certainly dealing with different problems.    

My Summer temperatures range from 70 at night to 110 during the day.

I built a heavily insulated indoor grow room with South facing windows to control the temperature.  What surprises me is how little supplemental light I need.  Basically I only need to extend the hours during the Winter. 

Our Winter months range from 20 to 70.  Even with all this insulation keeping 1000 gallons and 23 sq ft of grow bed at 75 degrees costs me about $2.50 per day.

Good luck with your project.   When July comes around I will be wishing I lived in Washington too.

We ask ourselves every Summer "Why do we live in Chico, CA?"

Comment by Rick Stillwagon on May 11, 2012 at 8:28pm

Here in Washington we get the least amount of clear sun than the entire rest of the US.  So, we have to rely on the diffused light that comes from all directions when overcast.  If I left the North side unglazed, I would have heavy shadows 9 months out of the year.  So for light gain here, an all glass house is best, but for the heat loss.  So far for our climate this design has worked best.  We get about a dozen days or so over 80 degrees, our temps here in the summer average in the high 60s and 70s.  Heating is the primary issue for most of the year depending on what you want to grow and the species of fish you want to raise.  Now I am working on root zone heating with water tubes and keeping the FT and sump heated.  Air temp is secondary and accomplished through the radiant heat and heat exchanger from the pellet stove,  This also helps to keep humidity way down due to the dry heat provided by the pellet stove.  I should have my heating costs down to about $2 a day this winter.  Last winter it ran between $5 & 8$ a day due to the inefficiency of the ancient stove I was using. 

Comment by Bob Campbell on May 11, 2012 at 6:07pm

The problem with green houses is over heating and freezing.

I assume the Cyan line is glazing.   My advice would be not to glaze the North side or North Roof.   Very little light gain and a lot of insulation lost. 

If you live in a dry climate include evaporative cooling. 

The sides and North wall should be insulated as heavily as you can afford.  I was talking to a guy who packed R30 fiberglass into 6".  He is a contractor and it really amazed me that he thought he was gaining R30.   Tighter is not better.

Forget the side window, unless cute is important.

Place the fan as close to the peak as possible.   Squirrel cage fans move the most air.  Stone or brick walls are good for thermal mass and will help even the temperature swings. Water barrels are even better, but thermal mass is not as effective as insulation in controlling the environment and water barrels take up a lot of space.