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Steam heat with mini-splits to whole house HVAC
Hello, I've got a ~1700 sq foot 100 year old house in Boston area with steam radiators for heating. From the bottom up: unfinished basement below that's 7 feet high, first floor has kitchen/living/dining/one bath, second floor has 3 beds/1 bath, 3d floor has one finished room (including radiator). We enjoy the steam heat but have never loved the big bulky radiators and there's huge variations throughout the house -- eg. bedroom toasty, dining room cold. We also like the mini-splits for A/C, but would like a few more rooms to be covered by A/C for those hot summer days. Meh...in the end this was basically livable for us. BUT THEN, came the basement refinish idea. That's when I realized, before I finish this basement, if I'm every going to change out this heating system, now is the time. And if I'm ever going to air condition more space, now's the time. After much consideration, what I'm thinking is as follows (BTW I have natural gas going to Burnham steam boiler right now).
- Change to HW boiler, wall mounted, and heat first floor with either retro-fitted in-floor radiant heat installed from below or regular slantfin/runtal radiators. (Navien combi here?)
- Air condition first floor with the existing mitsubishi 2-1 minisplits I have (this would require one head to be moved from second floor bedroom to first floor dining).
- Hydro-Air air handler (or heat pump?) in unfinished attic space to provide heating and cooling via newly installed ducts to second and third floors. (I just now heard of SpacePak...what about this?).
Would love the feedback, criticism, etc. of this plan...