Quote:
Originally Posted by rsmurano
If you are going to do anything in your attic, I would spray the attic roof with foam insulation. It might cost you $20,000 but we’ll worth it. We built a custom 5500sq ft home in GA using all spray foam insulation, walls and attic. When you walk in the attic, it looked like an igloo, but the attic was 70 degrees all year round, and that’s with 100 degree humid days or 15 degree nights. It is also a sealed attic meaning no vents for builders gap that allow bugs in. It was cheaper to heat and cool this house (5500 sq ft, 3 heat pumps) than our current TV house
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You are talking about a totally different house design. Your description indicates that you are actually cooling the attic space with your HVAC system. I have seen this done once in NC but the home used geothermal wells to supply water as the heating/cooling heat resource for their heat pumps. This is more efficient since the groundwater is typically 55 to 65 F year round and makes heat pumps use less energy than using ambient air. However, geothermal wells need to be permitted and cost money. In TV with our small lots, geothermal wells may not be practical.
In the case I mentioned they had an entire room dedicated to the HVAC condensers and geothermal water heat exchangers etc. Perhaps in Florida the equipment could be located outside since winterization is less of an issue, but you may need some equipment covers etc. that may need ARC approval.
None-the-less, spending 20,000$ for spray foam plus some more for geothermal wells and geothermal HVAC takes a very long time to recover your investment.
If your previous house used geothermal wells as the heat source/ heat rejection pool, I suspect that your lower heating/cooling costs are due to the geothermal water temperatures and not to the spray insulation.