We are finding that the house holds heat well. In winter that is a good thing. In summer, it is more difficult to cool the house. It gets cool at night in Colorado. The humidity can go up at night too. After blowing cooler air into the house all night through two open windows with all windows open the house still retains a lot of heat.
Night cooling
During the day with all the windows closed and two people working inside, the temperatures get high, although not as high as outside.We may be creating the heat ourselves.
You must also consider internal heat gain, both latent and sensible, from people, appliances, electronics, bathing, cooking, cleaning, laundry, etc. While the house may be superinsulated to retard heat gain or loss due to outdoor conditions, the structure is also retarding heat loss from internal sources. http://hvac-talk.com/vbb/showthread.php?139357-Night-cooling-of-super-insulated-home
So with these high temperatures we get uncomfortable while working inside.
Daytime temperature
I tried to connect the evaporative cooler that I used with the old windows, but after examining the new windows closely, I realized that the screws holding the windows were tightly connected and awkward to remove and I didn’t want to strip a screw in the new expensive windows just to put in an old cooler. So I gave up.
The small indoor evaporative cooler that I bought does not do much to cool the large living area so I moved it to the bedroom where it does an admirable job getting the temps down to about 73 but adding humidity to the room even with the opposite window open all the way. The humidity makes the cooling feel clammy which I never noticed with the larger window cooler.
So these efforts got me back to the radiant cooling study. I had planned to use a chiller to cool the water in the radiant loops and the storage tank that was installed for the fireplace boiler. I examined the pipes in the utility room and realized that I could run well water through the radiant pipe and out the drain, like when the system is being flushed. This leaves the storage tank out of the system completely.
I got out the FLIR camera to test the idea. This is the floor in the living room at about 2 PM.
Living Room Floor about 76 degrees
I opened one radiant valve and its drain and water began to flow through the loop. After 30 minutes I began to see some cooling in the radiant pipes.
Well water starting to cool floor
So cool water will cool some of the thermal mass maybe enough to retain that cold throughout the day. I didn’t want gallons of fresh water running into the septic tank so I closed the valve at this point.
Ideally I would figure out how to use an evaporator for the mini-split air conditioner to chill the water with the heat producing condenser outside. But that is a large project that I don’t have time for right now. If we can use the water that would run through the radiant pipes outside in the garden, it might be OK to just use our well water.
There can be an issue with condensation, however, the solution to that is to only run cool water when the humidity in the room is lower than the dew point.
In most commercial buildings, protecting against the risk of condensation can be quite simple. The coolest point in the fluid’s path through the radiant circuit is, by definition, the entering water temperature at the supply header of a radiant cooling manifold. Therefore, it makes the most sense to monitor and control the system from this point. Ensuring the entering water temperature is never lower than 1.6 C (3 F) above dew point effectively mitigates condensation. http://www.constructionspecifier.com/being-radiant-planning-in-slab-hydronic-heating-and-cooling
The easiest way to pump the well water used by the radiant cooling system outside to the garden is to use a sump pump and a collection tub. So I have one on order to try this new radiant cooling idea. And I’m wondering if the chillers I tried last summer would have worked if I had not tried to cool the whole storage tank but just the water in the loops instead.