Quote:
Originally Posted by Xringer
GreenHouse Mode would be very useful on sunny winter days (like today),
but in summer, some roof (heat-dump) vents would be needed,
plus some air-input vents adjacent to the ODU.
(To defeat the GreenHouse effect while trying to cool the house)! 
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Right now, the sun had made the outdoor air temperature shoot up to 40F.
So, my ASHPs are running less power, because of solar heat gain..
(Less power=less air flow over the ODU coils).
I would imagine, my proposed 32'x8'(?) greenhouse would be pretty
dang warm inside, even with a little 40F air being pulled into one end.. 
If it had double pane glass too??  Haha! |
Your ASHP runs with less power because it is a variable speed compressor moreso than less air flowing over the coils. When less capacity is needed your unit steps down. Supplying it with hotter air will allow it to put out more heat for the same amount of power which will cause it to step down to a lower the heat its making or even shut off sooner. Don't forget solar heat gain is reducing your houses need for heating too so the heat pump runs less and at less power to keep up too, at least until your wife gets warm and wants to cool off the house a bit with the open window thing.
With the air flow and solar heat production, I think double pane glass wouldn't make enough difference. If it was scrap glass that was free, sure why not, but it seems there is tons of free scrap glass on Craigslist if you search the free section for glass. I've been looking for the perfect size to mostly utilize a 4x8 sheet of plywood to create a solar air heater that pumps hot air directly into my house since I don't have an ASHP(at least not yet) but then again my furnace this winter has been running almost exclusively at night for most of December and hasn't powered on since 12/24 but it will tonight because today is a cloudy day and the low is 9 degrees, last week was much warmer though high and low for the week 49.6f and 19.4f average 31.8f but all week we got lucky with cloudless sunny days almost every day.
I'm wondering how to swing that with an ASHP in a well insulated and air sealed house, I'm not about to add loads of rocks to the house but I'm thinking to add jugs of water in the most sun exposed areas of that house to absorb the day heat and then the sun-enhanced air source heat pump efficiency could be used to heat the house with a set back opposite of what I do now with the house warmer during the day than at night? This probably won't work well for an owl like me in weather like what we've had recently but it would help when we actually get a cold December or in January when the heat actually runs during the day.