New Basement Heating: Radiant Slab? Comfort and Efficiency
Hello GBA Team – looking for some input on whether or not I should plan to include radiant slab in a new basement addition. Home is in at the very northern edge of Zone 4A, close to Zone 5A. Hot & humid summers, cold dry winters.
Finalizing plans for a 800 sqft. addition with a 9′ non-walkout basement and a 4″ slab. 2″ XPS or EPS rigid foam below slab.
Basement will initially be un-finished. But 2/3 of it will eventually be finished as a game/entertainment room that I expect will get frequent periodic use, especially in the winters. i.e. 4x a week in the evenings/nights. Floors will likley be ceramic or vinyl tile. Basement walls will be framed 2×4 or 2×6 with R-15 or R-23 Roxul. Home has an existing forced-air furnace w/ capacity for the addition. No current hydronic heating in the home.
I’m considering roughing in PEX for a radiant slab, while I have the opportuinty to do so. But don’t want to waste money on the PEX if there are better heating options.
My primary concern is comfort in the winter, secondary is system efficiency. My thought is to use the radiant slab primarily to keep the ‘chill’ off the room throughout the winter 24/7, say 60*. And then augment it with forced-air or hydronic baseboard heating to quickly warm up the room when in use. I’d add a dedicated boiler for this purpose, which may also support radiant in a bathroom above the basement.
Is radiant slab a good option for this scenario, making it worth adding PEX to the slab pour?
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