P-l-l-ease b-b-b-b-ear w-w-w-ith m-m-m-m-e.

April 7, 2008 7:56 PM

How do I arrange windows, doors and vents to keep my house warmest?

I live in the basement of a 5 floor backsplit, and I'm freezing my ass off.

The thermostat, which I'm welcome to adjust, is on the 4th of those 5 floors. The thing is, I have to crank it way, way up to get the thermostat to turn on the furnace and warm up the downstairs where I live. Since there's no one living in the top 4 floors, that's not an inconvenience for anyone, but it's pretty rude to the environment, not to mention my landlady's natural gas bill.

The problem is getting worse as it gets springier outside, because the upstairs gets heated by the sun, and the downstairs doesn't really. It'll fix itself come summer when I can turn the AC way down and just let the upstairs get hot, but right now I'm wearing 3 sweaters and my fingers are purple.

So, the basic configuration is thus (imagine the \s are stair cases):


Bedrooms
...............\
..................Living room
.............../
Family room
..............\
.................Garage & Laundry room
............../
My apartment

There are doors between all the levels except the top two. Most of the cold air arrives via the garage / laundry room level, which isn't well insulated, so I keep the door between my apartment and that level closed all the time. I've closed the upstairs vents to try and keep the heat down here where I need it.

But I'm wondering about other levels. Should I open the doors between the family room and living room and garage levels so that some of that cold garage air can mingle with the warm upstairs air? Or will cold air falls / warm air rises negate mingling? Crack a window near the thermostat to help even out the temperature so the thermostat kicks in? Just crank up the temperature setting so the upstairs swelters and I finally get some heat? Is there some other way to get warm air to come down to where I need it that I'm not thinking of?

posted by jacquilynne to home & garden (15 comments total)

As far as energy use is concerned, it doesn't matter where the thermostat is. If you heat the house to such a temperature that you are comfortable in the basement, the energy required to do so and the distribution of heat through the house will be the same if the thermostat is on the fourth floor or in the basement.

If you open the door to the cold garage or open a window near the thermostat, you are increasing the amount of energy needed to heat the house. You'd be better off just to turn the heat up to achieve a comfortable temperature in the basement.

Are you sure all the upstairs heat registers are fully closed? If they are and the furnace is pumping warm air into the basement, but you still aren't warm enough, the problem is likely that you are losing a lot of heat through the walls and floor of your apartment (are they insulated?) or through air leaks. Can you use a few space heaters in the basement, rather than heating the whole house?
posted by ssg at 8:21 PM on April 7, 2008

Have you considered getting a space heater, or an oil filled radiator?
posted by fiTs at 8:23 PM on April 7, 2008

A space heater is not an option. My entire apartment is basically on a single breaker and it *barely* manages to hold up to the existing electricity demands. I tried bringing my landlady's space heater downstairs (she's been in the hospital for months, hence the upstairs being empty) and it immediately blew the breaker.
posted by jacquilynne at 8:37 PM on April 7, 2008

Can't you just move the termostat? Even temporary? A gas forced air heater's thermostat is just two wires (three if there's also AC) that have max 12 volt on them. It's easy to temporaryly move it by running a wire (speaker wire/telephone wire it doesn't matter much) towards your appartment. It's no rocket science, basically everyone can do it. Just remove the thermostat from the wall, remove the wires (mark them or take a picture). Extend the wires and connect the thermostat to the end of the wires. Since you say the other floors are not used you could run the wirse through the stairwell or even outside. Then you will be in control of the heat and you can close almost all the heat vents on the upper floors, saving your landlady and the environment.

I hope she gets well soon.
posted by maremare at 8:50 PM on April 7, 2008

The garage level will leak cold air downwards, as you suspect. If there is a door leading from the garage directly to that floor, can you insulate the door and block the drafts? An old blanket or duvet from a thrift shop that you could hang from above the door would help, as would some kind of sausagey draft excluder at the base of the door.

If the entire garage/laundry room floor is poorly insulated, can you strategically open blinds for any windows on that floor so you can passively heat it? And even though your basement doesn't get as much light as other floors, can you still open blinds when the sun's there and close them when it goes? Are there any obvious drafts on your floor that you can plug?
posted by maudlin at 8:57 PM on April 7, 2008

If you heat the house to such a temperature that you are comfortable in the basement, the energy required to do so and the distribution of heat through the house will be the same if the thermostat is on the fourth floor or in the basement

This is true only if the entire house is open to circulating air, and all the central heating registers in the upper floors are left open - which would be an insane way to arrange things. The point of a thermostat is to make the heater keep the temperature near the thermostat nearly constant.

The only way the thermostat is actually going to do you any good is if you can indeed rejig the wiring to put the thermostat inside your living space.

If you can't do this, but you have some non-thermostat-based way of turning the heating on and off, then close off all the heating ducts to the upper floors before firing up the heater, and then just turn the heating on when you're cold and off when you're warm - you will be acting as a kind of manual thermostat.

Something else that may work is to tape cardboard boxes over some of the upstairs heating registers, cut holes in the sides of those boxes to suit a box fan, close any registers without boxes taped over them, and use box fans to push sun-heated warm air from the upstairs rooms back into the heating ducts. If the only place that warmed air can escape from the ducts is the registers in your apartment, you won't need to burn so much gas. Box fans don't suck much juice. You'd also want to arrange some flap valves in your cardboard boxes to stop the central heater blowing hot air into the upper rooms when the box fans are off. This would be a pain in the arse to look after, though, unless you have access to a breaker panel that lets you easily kill all the electricity in the upper floors from near where you live.
posted by flabdablet at 1:13 AM on April 8, 2008

A space heater is not an option. My entire apartment is basically on a single breaker

How 'bout using an extension cord to connect to a different circuit (upstairs, say)?
posted by hjo3 at 3:27 AM on April 8, 2008

Do not use an extension cord with a space heater please. They draw too much juice and it just isn't safe. I am pretty sure it is also a code violation.

You need to insulate against drafts and make sure that most if not all of the registers on the upper floors are closed while your registers in the basement are open. You probably also want to check the ducts leading to the furnace to see if there are any dampers that are thwarting this scheme, say for instance a damper which is partially closed in the ductwork leading to the basement registers. You might also find a damper which leads to the upper floors which would simplify closing off most flow to the upper floors.
posted by caddis at 7:10 AM on April 8, 2008

What does a damper look like and how do I find it?
posted by jacquilynne at 7:22 AM on April 8, 2008

The damper is inside the duct but you can spot it by finding a lever arm mounted to the duct. The arm position would correspond to the damper position, so if the lever parallels the duct the damper is open and if it is at a right angle to the duct the damper would be fully closed (see Fig. 4) although there are other designs.
posted by caddis at 8:01 AM on April 8, 2008

This is true only if the entire house is open to circulating air, and all the central heating registers in the upper floors are left open - which would be an insane way to arrange things.

Not to be pedantic, but this is wrong. The energy required to maintain the desired temperature in the basement is the same no matter where the thermostat is. The furnace can't change where it directs the warm air based on the location of the thermostat. It may be more convenient or easier to maintain the desired temperature with the thermostat in the basement, but it isn't going to save energy (unless there are times when the basement is warmer than desired).
posted by ssg at 8:06 AM on April 8, 2008

this is wrong

No it isn't.

If you put the thermostat in the basement, and close off the registers in the upper floors, then the heater will deliver warm air only to the basement until the basement-located thermostat tells it to stop.

If the thermostat is on the fourth floor, and you close off the registers in the upper floors, then the basement will bake as the heater attempts to warm a permanently cold thermostat that it can't get heated air to.

The only way the basement temperature could possibly even come close to being regulated by a thermostat four floors up is if (a) the registers in the room with the thermostat in it are open and (b) the rate of heat loss from the basement is very similar to the rate of heat loss from the room containing the thermostat.

The furnace can't change where it directs the warm air based on the location of the thermostat.

Quite so. But the residents can and should change where the furnace directs the warm air, by closing registers in unoccupied rooms. This will undoubtedly use far less energy than heating the entire building.
posted by flabdablet at 8:41 AM on April 8, 2008

ssg is correct. To a first approximation, the temperature in the basement will always be some percentage of the temperature upstairs. It will not be perfectly accurate but good enough for jacquilynne's extreme situation. To get warmer downstairs just keep raising the thermostat on the top floor until the downstairs is comfortable. Moving the thermostat downstairs may make temperature sensing more accurate but it does nothing to solve the distribution of heat problem.

The best you can do is to figure some way to direct less heat upstairs and more heat downstairs by adjusting vents or dampers.

Or else, can you move your living quarters temporarily to the unoccupied upper floors and just sleep in the basement?
posted by JackFlash at 9:24 AM on April 8, 2008

But the residents can and should change where the furnace directs the warm air, by closing registers in unoccupied rooms.

The OP specifies in the question that the upstairs vents are closed. I take that to mean that the registers that aren't in the basement are already closed.

I think we are arguing about different things here. I'm talking about a situation where the thermostat is moved and all other variables are held constant and you are talking about a situation where the thermostat is moved and registers are closed.
posted by ssg at 9:29 AM on April 8, 2008

The OP does indeed specify that the upstairs vents are closed.

This, in turn, means that the furnace is no longer capable of affecting the temperature of the thermostat (since it's upstairs, behind closed registers). The thermostat, in its current position, is effectively acting as a simple on/off switch for the furnace. Set the thermostat temperature higher than the air temperature in the room where the thermostat is, and the furnace will come on and stay on; set it lower, and the furnace will stay off.

The only way to bring the furnace back into any kind of thermostatic control, without moving the thermostat, is to open up the vents in the room where the thermostat is at, and heat that unoccupied space as well as the basement. This is going to cost more energy than heating the basement alone.

The OP also mentions that the upstairs rooms are currently quite well warmed by solar gain. Which means that in order to turn the furnace on at all, it's necessary to crank the thermostat way up. If the furnace is on, then the basement will definitely get hotter than it needs to be, since the furnace is just going to keep on blasting in there - the temperature at the thermostat is not going to change. The only way to avoid oveheating the basement, without moving the thermostat, is to turn the furnace on and off manually: perhaps by running upstairs and fiddling with the thermostat; perhaps by flipping breakers downstairs.

It may appear as if the basement gets hot because the thermostat is set to a crazy-high number, but that is not the case. The basement gets hot because the furnace, if it's on at all, is delivering uncontrolled heat to the basement. And this will happen for any thermostat setting higher than the current air temperature in the unoccupied upstairs room.

The correct fix for all of this is to relocate the thermostat into the living space so that the furnace knows what to do, and leave the upstairs registers (vents) as they are now - closed. That way, the thermostat can be set to an appropriate temperature instead of a random sufficiently-high one, and only the spaces that the furnace will be using energy to supply heat to will be the spaces that actually need heating.

I'm talking about a situation where the thermostat is moved and all other variables are held constant and you are talking about a situation where the thermostat is moved and registers are closed

Given that the registers are currently closed, those look like the same case to me.
posted by flabdablet at 11:40 PM on April 9, 2008