ChristianPatriot
Grandmaster
+3 on building envelope first. We are 2 years into our Insulated Concrete Form (ICF) home. 2 story on a basement with an attached garage. 2400 sq ft living space, over 1200 sqft [mostly] unfinished, unheated basement. We choose zoned radiant floor heat (including the garage) with a forced air air conditioning. We were on the fence between this & using a mini-split for ac, but choose forced for air circulation/filtration.
All radiant floor heat components are drinking water certified, so we are able to use an "open loop" setup where the floor heat & domestic hot water are sourced from the same high efficiency water heater (Westinghouse 80 gallon, 97% efficiency 25 kbtu - 76 kbtu). I have plans to install a wood burning stove in the garage with a hot water loop to preheat water to the hot water heater. We originally intended to put the wood burner in the basement, but after 2 years of living here, I think that even the smallest wood stove down there would run us out of the house. The basement stays a consistent 65 degrees even without heat.
ICF homes are by design tight 12" thick wall sandwich (3" polystyrene form, 6" steel reinforced concrete, 3" polystyrene) that are tight due to the monolithic concrete pour. When factoring in little air movement through the walls, I have heard wall r-value ratings as high as R-65. Radiant floor heat provides consistent heat where you want it - at your feet. The second floor of our home is where all of the bedrooms are & we keep it set @ 65. A little cool when going to bed, but at least 3 of the 6 generally wake up in the middle of the night sweating because of the nature of the heat.
We have a family of 6, use LP gas for everything except our stove (water heater, dryer, cooktop, gas grill) and our average LP usage is around 900 gallons (2 fills/year). I installed the radiant heat system (hot water heater, pumps, controls, etc), my builder installed the radiant floor heat tubes; if I recall correctly, total HVAC cost (radiant system plus AC) was around $25,000.
Wow. I’m sure it’s awesome but, man, $25k!?