Hello all, I am new to the forum and interested in the upcoming PDC. I have a question regarding measuring thermal storage of a house. I am in the planning stages of creating a food forest and home and shop in South Phoenix.
7 years ago I was staying in the Phoenix Earthship in Taos. At 11am on a June morning I stopped for ten minutes to marvel at the airflow through the doors of the greenhouse. This Earthship has a large greenhouse with a large central opening skylight; the convection for the solar gain was impressive to experience/feel. The observation led me to thinking about using a greenhouse as a heat pump for a home in the desert.
My current plans involve a large basement under the structures, with air tubes feeding ventilation from the north side. The earth is 72 degrees at 5 feet here. The air path to ventilating the greenhouse will turn the structure into a double pass radiator of sorts for the cooled/circulating air. I also intend to reuse the excavation to make CEB walls, and wish to attempt to create a Rasta like brick/panel to insulate the outer shell. The roof will be a variation of a insulated cool roof using radiant barrier under a metal deck.
My question is how do I factor the thermal storage/temperature change of the basement, walls and floor of the structure, and calculate the r values needed on the walls to insulate for 100 degree evenings and 115-118 degree days for weeks at a time? I believe it takes about 3 months of lag time for the ground temperature to come up or down in a non insulated berm. Curious to run the math, and gather inputs on factors I might not have seen.