Wind Chill question

[rmihalek]

I'm pretty sure we all know that wind chill affects exposed skin; it's a measure of a rate of cooling, not the actual temperature. So, does this same prinicipal apply to our homes? Normally in my house, when the ambient temperatures are above 10F (-12C), if there's no wind, I can keep the wood stove cranking and the oil furnace won't ignite. Lately however, it'll be 15F (-9C) and with the wind we've had the past few days, I'll be runnin' the stove wide open and can't keep up: the oil furnace kicks in. My house is not drafty: new windows, wicked amounts of insulation, etc. I'm thinking that houses are like people in that they lose heat more quckly when it's windy.

 

[Multifaceted]

Hard to say...

It's currently 11°F with a wind chill factor of -6°F and I've been running the stove since I got home. It's about 70° inside right now. My house is a little drafty around the doors, I really need to rip out and redo the weather stripping. It's pretty damn windy today, but I do notice that if I let the stove settle down too much without reloading, the internal temp will drop quickly.

My stove and chimney are in the center of our home on the bottom floor (split foyer) so when the chimney warms up it radiates heat through the top floor in addition to the stove. The rooms on the perimeter that are blocked from the radiating heat stay about 4-5° cooler, but it's bearable. I actually like it on the cool side in our bedroom. We keep the thermostat for the electric furnace set to 66° and it really only comes on when we're away at work.

 

[crowbuster]

your house has trouble somewhere. Have them run the test where they pressurize your house and use the googles to look for heat loss. You will be amazed.

 

[Philbert]

So, does this same prinicipal apply to our homes?

Yes.

Sort of.

It's like blowing over a bowl of hot soup; moving air will cool off your house faster (but your siding won't get frostbite!).

Philbert

 

[anlrolfe]

Make a natural windbreak with evergreens about 50' away from the house on the windward side. Plant them far enough away so that maintenance won't be an issue but close enough to be effective. They won't STOP the wind but they will buffer it and decrease its impact.

Anything you can do to reduce air infiltration will also reduce energy loss. Weather stripping and calking can do wonders. Replace worn out doors and windows.

How tall is your foundation? Add banking. In the pre-season hay bales or in the dead of winter mound up the snow. If your basement is unfinished add rigid polystyrene along the interior.

 

[jwilly]

The wind creates a high pressure area on the windward side and a low pressure on the lee side. Low pressure sucks the warm air out of the house and the high pressure supplies the cold air to replace it.

 

[ChoppyChoppy]

I don't notice much difference in my house unless it's really windy outside (50+mph)

Putting plastic on my windows helped a ton. They are "builder grade" and the wind would spread the 2 sections apart and blow fine snow and silt.

 

[Slicksty6]

Attic insulation is your best bet. Lay it on thick and be sure it goes all the way to the top plate of the walls. Also check for leakage around ceiling fixtures on the underside of the attic. The chimney effect created by air leakage into the attic will suck the heat out of the house. Add wind on top of that and the number of air exchanges per hour in the house goes up dramatically.
Of course leaky doors and windows should be addressed also.

 

[Streblerm]

I think it is fairly clear that windchill will affect your house’s rate of heat loss even if it is tight and well insulated. Insulation doesn’t stop the movement of heat, it only slows it down. Higher wind speeds increase the rate of heat loss through convection so heat will be lost faster through the surface of your house when the wind is blowing. Windchill doesn’t arbitrarily affect people’s skin. It is a measure of the rate that any object loses heat.

Agree that air infiltration is probably a bigger factor. I know it is in my house.

 

[echomeister]

A surface warmer than the surrounding air will lose heat to the air near the surface. If the air is still there is tiny layer of warm air hovering over the surface that acts as a bit more insulation. The wind blows this layer away and causes more rapid heat loss. That's how I think of it.
So if your house outside is already cooled to near the air temp due to good insulation the wind chill effect is minimal.

I would say you have some air leaks.

 

[greenskeeper]

Humans are only affected by the wind-chill, not objects like houses.

Wind chill is the perceived decrease in air temperature felt by the body on exposed skin due to the flow of air.

 

[NSMaple1]

Therefore the house is affected by the wind chill.

 

[Philbert]

Technically, it is a measure of convective heat loss

Philbert

 

[jimrb]

Those of you that have water cooled vehicles will find a radiator someplace. The radiator helps the engine lose heat by moving air across its fins. Isn't a house the same thing? Heat escapes the house in an attempt to seek equilibrium. If you have a lot of air/wind blowing against the house, doesn't the air/wind cause the heat leaking out of the house to escape faster? The outer skin of your house is like a radiator and the physics concept of temperature trying to achieve equilibrium means more heat gets carried out if that "skin" of heat on the outside of the house gets blown away. Also if your house is leaky, cold air can blow in the house faster than if it meandered in. Of course I never had a formal physics class so I could be all wet, or cold about my theory. Here is an article, and there are others that explain the science which is more about air infiltration. To me, air infiltration is kind of like that radiator analogy I was trying to use. https://passivehouseplus.ie/magazine/feature/windy-or-cold-weather-when-does-heating-demand-peak

 

[Philbert]

Wind can cool in a couple of ways:

1. cold air infiltration and leakage of heated air;

2. convective currents moving heated air away from the outside faster.

We might call these different things, but wind makes a difference.

Philbert

 

[Streblerm]

Humans are only affected by the wind-chill, not objects like houses.

I suppose technically wind chill factor is a “feels like” equivalent measurement on human skin, but to suggest that only human skin is cooled by moving air (fluid) is misleading at best.

The radiator, or any forced air heat exchanger is a good example. Blowing on a hot spoonful of soup is another. Convection ovens cook faster by introducing movement of air. There are lots of practical examples of convective heat loss. There’s really nothing special about humans that makes them more or less susceptible to the laws of thermodynamics.

 

[Streblerm]

It's a "feels like" temperature to human skin, inanimate objects don't have feelings, and we are talking about the "wind chill factor", not thermodynamics.

OP asked if the same principle applied to heating his home. That principle is thermodynamics.

 

[Philbert]

. . .we are talking about the "wind chill factor", not thermodynamics.

Re-read the original question:

. . . So, does this same prinicipal apply to our homes? . . . I'm thinking that houses are like people in that they lose heat more quckly when it's windy.

Philbert

 

[NSMaple1]

It's a "feels like" temperature to human skin, inanimate objects don't have feelings, and we are talking about the "wind chill factor", not thermodynamics.

Wind chill factor is all about thermodynamics.

 

[Streblerm]

It is true that no object animate or not will get colder than the ambient temperature from wind chill.

What does happen is that objects, all objects, lose their heat faster when wind blows. The reason it feels colder on your skin is because your body is losing heat at a faster rate. The “wind chill factor” tries to quantify this by giving an approximate temperature where the body’s rate of heat loss would be the same.