Moving heat, am I losing my mind?

[Dustin]

For some background..

I live in an older, 1955 era house with two levels. We don't use the upstairs hardly ever, except for when I visit my man cave, aka the ham radio room.

There is a door on the stairs, in the main living area where my stove is located. Today, I decided to leave the door open and let some heat get upstairs instead of running the space heater.

Now, the weird part. It's comfy upstairs, and even warmer then normal downstairs, 73 on the thermo, which I usually can't get past 71. It feels nicer downstairs, and the heat seems to be more, even...

The room that is usually ice cold when I'm not in it is directly above the stove room. Is it possible, that with it being warmer up there by letting the stove heat go upstairs, that I'm not losing heat through the floor above the stove? I might just be crazy, but it feels that way to me. When I first opened the upstairs door today there was a huge blast of cold air flooding into the lower level.

Also, I'm young and don't claim to be very home smart. Is it a bad idea to leave the big room upstairs "it's huge" closed off and cold? Can I cause any eventual issues that way?

I usually always close the door to the stairs, even when I go up there twice a week. Sometimes, it gets down to 50 degrees or colder up there.

Thoughts?

 

[begreen]

You want to watch for mold forming when the space is not heated, particularly in a damp climate. If leaving the door open makes it more comfy downstairs I would just leave it open.

 

[MnDave]

Are there ducts to the upstairs? If so, are the dampers in the registers closed? Is there a separate return duct or just the stairwell?

Where I am going with this is, you may have paths for cold/warm air to/from your upstairs that you are not thinking about.

My parents have a Cape Cod (50's) . They close the registers. They shut the door.

Now consider that the floor between the main floor and the upstairs is not insulated. But the attic is.

In this case, you essentially have a refrigerator upstairs. The cold air will come down the registers/returns/stairwell into the lower level. And you will have significant heat loss between the main and upper floor.

If you keep the upstairs warm, you can reduce the amount of cold air dropping into the main and basement levels. Basically, this is what you have done by opening that stairwell door and heating the upper level. If you are doing this with wood vs gas/LP/electric you will not notice the added energy to heat the upper level, but it is there.

MnDave

 

[Dustin]

No ducts... But, I see you point. I imagine with that door closed, the entire ceiling of the stove room, which doubles as the upstairs floor is probably one big heat sucking heat sink?

Interested to try this, leaving the door open for the next week and see how it all does...

When I shut the upstairs off, it's closed pretty tight. So tight that the lower half of the house is 72' and the upstairs is 55. So in theory, it would be like having an uninsulated attic maybe?

I know I'm over thinking, but it's fun to share these random heat thoughts...

 

[jdp1152]

Unless you're insulating between floors it's always good to have your upper floor warm. Heat and cold transfer are at odds with one another. Cold air wants down, warm air wants up. Find a better balance by warming your upper floor which has a nice insulated cap on it (hopefully) when you want to spend time in your heated downstairs. An insulated buffer behind sheet rock (or in this case, a heated space behind sheet rock) will actually push slightly warmer air down while the hotter air rises making it easier to warm the lower floor more. If you leave it cool, it's for the most part acting like an uninsulated attic. It's a little more black and white when talking about a wood stove as your primary source, but I've been working on a lot of calculations when deciding on mulizone heat systems vs whole house and also thermostat placement. Regardless, the takeaway here is heating bottom floor, not allowing heat to top floor is bad. Heating top floor, but not heating bottom floor is fine. Heating both, even if slightly, is better if your concern is the bottom floor

 

[jdp1152]

To illustrate this point..you don't see too many basements/main floor borders insulated. The cost of insulating doesn't produce ROI. you're better off to insulate or air seal the rim joists which produce major temp gradients. Or just google convection.