Home heating - Do you heat basement?

[3Mer]

I thought I'd post this question that I've been wondering about since we are currently in another bout of extreme cold here in western WI.   I have forced air heat, and had been leaving the basement vents open.  Thinking heat rises, so this should be not wasted heat.

Do you think it is more cost effective to keep doing this, or should I close the basement vents?

[Bob W]

Heat does not rise, it radiates in all directions.  Hot air rises.  Generally no need to heat if unused.  I do heat mine but rarely use it.  I like the air to circulate there.

[big_owl]

Yes our basement is heated.  We are in the process of finishing it ourselves - prior to that it was a cement slab with some reflective insulation nailed to the walls.  There were still two forced-air vents blowing into the basement, but with all the exposed cement it was pretty wasteful in my mind. 

Now that we've properly insulated the walls and added a subfloor, those same two vents provide much more bang for the buck.  In addition I put a wood stove down there which has been very effective.  Even with temps in the 30s outside, I'm able to keep the entire house at around 60 degrees (two stories, 3500 sqft) just by leaving the door to the basement open.  Air literally blows up the stairway.  I put it down there primarily to heat just the basement as well as ambience, but it's been a pleasant surprise.  With a subfloor, the ground temp is around 70 degrees when I'm running the stove.  Compare this to the old slab temp in the low 50's in the winter, that's a huge energy savings. 

I guess the moral of the story is that if your basement is completely insulated then it would probably be ok to heat it, but if the walls and floor are not then you're wasting a lot of money trying to heat it. 

[Mr. Frugalwoods]

Here in Boston, our basement stays around ~50 degrees in the winter with no heat beyond the ambient throw-off from the hot water heater and boiler.  The first year we owned it I kept a thermometer down there to check on the coldest nights, but it never got into the danger zone for pipes (under 45).

If your basement can stay at similar levels without heating... I'd say save the money!

[3Mer]

I think it is wasteful - my basement is not finished - just concrete walls.  However, it is going to be below zero temperatures for the good part of this week.  Should I worry about pipes freezing if I don't have the heat on down there?   

[Villanelle]

Not all that heat energy is rising.  Some is going to try to heat the concrete floor and walls, and all the stuff in your basement. 

For truly frigid weather, I might leave on vent slightly open if your basement tends to get exceptionally cold, but I suspect that by it's basement nature, it is fairly insulated and isn't going to get down into the 30s, much less to freezing.  Other than that, nothing, if you aren't using the space.  And even if you are, I'd consider trying to move those activities elsewhere during exceptionally cold weather so that you can save the money and energy. 

[TheMoneyBadger]

We heat our basement because it's a space that we use all the time.  If we didn't, I'd close off the vents.  In a previous house I left it mostly unheated and installed insulation in the floor joists to reduce the, fairly minimal, loss of heat through the floor into the basement.  As an added bonus, that reduced noise transmission between floors when we did end up finishing the space.

[Emilyngh]

I thought I'd post this question that I've been wondering about since we are currently in another bout of extreme cold here in western WI.   I have forced air heat, and had been leaving the basement vents open.  Thinking heat rises, so this should be not wasted heat.

Do you think it is more cost effective to keep doing this, or should I close the basement vents?

No, there is definitely "wasted heat;" probably little of it will wind up being transferred upstairs through the rising hot air.   Eg, our upstairs has only baseboard heat, not forced air.   Even when the hot air is blasting downstairs, without the baseboard heaters on upstairs, it's cold upstairs.

I would only heat a basement enough to keep it from freezing if there were things in it that I was concerned about (eg., pipes, paint, etc).   Here, it has never gotten that cold, and I would be surprised if it ever did.

[3Mer]

OK, I closed one vent that is in a basement room that has no water pipes (it's the room below the living room).  The only other vent is by the washing machine - I left that one open.  Just the one should be enough to keep the pipes from freezing - most the pipes are near there or in the room by the furnace, where there is no vent.

Thanks everybody for your advice on this!

[Davids]

Our basement does not have heat or ac source. However that is not bad because it is cool in the summer time down there and in the winter time well you can wear a sweatshirt and be fine down there.