Hello, Bogleheads. Looking for input on an HVAC decision, as this is very much not my field of expertise.
Brick home. Built 1919. ~2200 sqft.
Location: St Louis (Hot summers. Sorta-cold winters -- cold enough to use heating, anyway.)
Upper floor is bedroom, spare bedroom, office, bathroom.
Downstairs is kitchen and other assorted living space.
Unfinished basement.
Current system:
Central air, gas furnace.
The A/C and furnace are each from 2012.
Single-zone with thermostat downstairs.
Situation:
The furnace gets the job done in the winter.
And the A/C has (so far) been able to keep up in the summer. (This is our first summer in the home. Moved in last October.)
The issue is that, for ~8 hours per day, we're in the master bedroom, with no other part of the home occupied. And for another ~8 hours per day, I'm in the office, with no other part of the home occupied. So that means we're heating the entire home in the winter, when really we only want one room heated. And in the summer we're cooling the entire home (making the downstairs MUCH colder than is needed, especially given that there's nobody down there) when we really only want one room cooled.
The other issue is that the spread between the upstairs and downstairs temperatures grows overnight, so it gets hotter and hotter upstairs without getting hotter downstairs, so the A/C never kicks back on.
Our motivation, if we decide to make any changes, would not be that we expect a financial payback but rather environmental concerns and a desire for better comfort.
We've gotten quotes for changing it to a two-zone system ($6,400). And we've gotten quotes for installing a 3-zone mini-split system upstairs, with heads in the bedroom, office, and spare bedroom ($13,800 before IRC 25C tax credit).
The mini split system seems like it would be most efficient as well as best for comfort (i.e., best ability to provide desired temperature at the desired time and place). But it's more expensive. And is it dumb for any reason to have both central air and a mini-split system? One downside I can think of is more potential maintenance, with more total pieces of equipment in operation.
Brick home. Built 1919. ~2200 sqft.
Location: St Louis (Hot summers. Sorta-cold winters -- cold enough to use heating, anyway.)
Upper floor is bedroom, spare bedroom, office, bathroom.
Downstairs is kitchen and other assorted living space.
Unfinished basement.
Current system:
Central air, gas furnace.
The A/C and furnace are each from 2012.
Single-zone with thermostat downstairs.
Situation:
The furnace gets the job done in the winter.
And the A/C has (so far) been able to keep up in the summer. (This is our first summer in the home. Moved in last October.)
The issue is that, for ~8 hours per day, we're in the master bedroom, with no other part of the home occupied. And for another ~8 hours per day, I'm in the office, with no other part of the home occupied. So that means we're heating the entire home in the winter, when really we only want one room heated. And in the summer we're cooling the entire home (making the downstairs MUCH colder than is needed, especially given that there's nobody down there) when we really only want one room cooled.
The other issue is that the spread between the upstairs and downstairs temperatures grows overnight, so it gets hotter and hotter upstairs without getting hotter downstairs, so the A/C never kicks back on.
Our motivation, if we decide to make any changes, would not be that we expect a financial payback but rather environmental concerns and a desire for better comfort.
We've gotten quotes for changing it to a two-zone system ($6,400). And we've gotten quotes for installing a 3-zone mini-split system upstairs, with heads in the bedroom, office, and spare bedroom ($13,800 before IRC 25C tax credit).
The mini split system seems like it would be most efficient as well as best for comfort (i.e., best ability to provide desired temperature at the desired time and place). But it's more expensive. And is it dumb for any reason to have both central air and a mini-split system? One downside I can think of is more potential maintenance, with more total pieces of equipment in operation.
Statistics: Posted by ObliviousInvestor — Thu Jul 18, 2024 6:36 pm — Replies 10 — Views 595