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Heating efficiency?

I have a one story house with a finished basement just North of Boston. I have an oil fired boiler and hot water baseboard heating in my home. The heating system has two zones, one for the basement and one for the upstairs. I currently don't heat my basement during the winter because I don't go down there very much and it stays about 59-60 degrees when it is cold out.

I am wondering if I could get better heating efficiency if I did turn on the heat down on the basement with the thinking being that there would be good transfer to the first floor as heat rises and it would be easier for the boiler and heating system to heat the basement. Is this right or wrong? I am naive about what would make the most sense in this case and would appreciate any advice people could offer.


Re: Heating efficiency?

The beauty of a forced hot water boiler/baseboard system is that it can be zoned for different parts of the house, as is your system----this provides comfort zones, as well as fuel savings due to less fuel consumed.

I assume that your main motivation in this is to reduce the amount of fuel oil consumed during the cold winter months.

Any overall heating improvement due to added heat to the basement, assuming some of it will rise to the upper floor can perhaps only be determined by doing a test run to see if there is any improvement, vis a vis the extra amount of fuel that will be expended.

I can think of a number of factors that might be at play: the presence or absence of insulation between the basement & the upper floor, the presence or lack of exterior wall insulation; the presence or lack of double pane windows/storms; the height of the concrete/stone foundation; etc, etc.

Added basement heat will always allow some transference of heat from the basement to the upper floor; one possible thing that may or may not happen is that you might be able to inject enough heat BTUs into the stone walls & concrete floor structures of the basement to create a radiant heat situation, where the heating zone for the basement stops firing and the built up basement heat radiates to the upper floor-----of course, the opposite could happen, the concrete walls/floors could just absorb a lot of heat (heat sink effect) & inject it into the ground & that will just mean a larger oil bill.

I always advise homeowners that the PRIORITY items to look at for greatest heating bill savings is to make sure there is adequate exterior wall insulation (R19), and attic insulation (R40)---temporarily remove the electric receptacles at the inside base of the exterior walls; shine a flashlight to see if you can feel or see any insulation; if the previously installed insulation has settled over the years (check the upper parts of the exterior walls), or if there is NO insulation in the exterior walls, then call a local insulation co. to have cellulose insulation blown into the exterior walls---they work from the outside, can do it all in one day, & the cost is moderate---it pays for itself in a very short time-------far too many homeowners completely ignore this simple procedure that can reduce winter energy bills by as much as 50%, especially if it is combined with installing new vinyl double pane windows, especially if you now have single pane windows without storms.

This is known as "tightening up the building envelope"; insulation pays amazing dividends all year round---it keeps the heat inside during the winter and keeps the air conditioned cool in during the summer---a great way to save $$$ in winter & summer.

Also, if you happen to have natural gas pipelines in your neighborhood, and the oil-fired boiler is over 10 years old, it would be prudent to consider switching to a newer, more efficient gas-fired boiler; oil is a reasonable choice in the meantime, but fuel oil keeps going up in price, while natural gas, mostly produced in the U.S., is getting cheaper.

Re: Heating efficiency?

One common misconception is that heat rises. Heat does NOT rise. Heat radiates uniformly in all directions from hot to cold. Hot (warm) air rises. For that reason, it is probably warmer near the ceiling of your basement than it is on the floor.

In a way, you are heating your basement now. I assume that your boiler and hot water heater are down there. They get hot when in operation and that heat is radiating into the basement. That heat warms the air and the air is rising and collecting in the basement ceiling, under first floor floors. Some of that heat radiates upstairs into the first floor, but a lot is lost in the area where the floor joists meet the outside rim joist. If you insulate that, you can save some heat.

If the basement walls are insulated, they will retain more heat, but with out insulation, they become a giant heat sink. It will be difficult to maintain a temperature much above the ground temperature on the other side of the basement walls. But whether insulated or not, heating additional square footage of wall, ceiling, or floor space will cost more money, no matter how well insulated it is. Its just that the better the insulation, the lees additional money it will cost.

My recommendation, make sure the upstairs floor is well insulated per the post above. The insulate the basement walls and the rim joist area. Do not heat the basement, but if it is better insulated, it will retain more of the waste heat from the boiler and hot water heater and the temperature down there should rise some. Just be careful not to make the basement so tight that the boiler and the water heater can't get any air.

Re: Heating efficiency?

Thank you brewster and Keith for your posts. Your points are well taken and I think I will look more into better insulating the outside walls on my first floor.

How should I judge if the walls are insulated well enough now? I have a feeling that they are not as it is much colder and borderline drafty around some of them. If I check through the electrical receptacles and do see insulation, how do I know if it is sufficient?


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