Hydronic radiant vs heat pumps
I am new but I’m building a new house 2700 sq ft with additional 1200 sq ft basement in Scarborough, Maine (Zone 6) which will have 2 inches of closed cell spray foam on basement walls. The entire envelope has R-6 Zip R sheathing and all exterior walls are 2×6 Planned to be filled with open cell foam, 11 inches of Open cell spray foam in the attic roof. Trusses are 2×8 but I will have strips of 1” XPs foam over the edges with 1.5” wood screwed over that followed by 3/4” strapping which should result in no thermal bridging after spray foam is filled flush to strapping.
I have two questions.
first, with the zip-r sheathing, would you still recommend the open cell spray foam or would my money be better spent elsewhere with rocksul and a blower door test.
second, the bigger question.
I have been planning on installing a hydronic radiant system throughout the whole house with a wall hung viessman vitodens 100 propane boiler. My wife would like ac for the humid summer months here in Maine so I’ve been considering adding a 5 zone Fujitsu air sourced heat pump. My question is this, would I be better off going solely with heat pumps for my heat and ac and scratch the radiant and put that money into solar? Or should I install the radiant and have the heat pumps for ac and auxiliary heat?
GBA Detail Library
A collection of one thousand construction details organized by climate and house part