Electric Heaters & Savings on Heating Bill

In My Humble Opinion
1

My co-workers seem to like the A/C at a much lower temp than I do, so I have a small electric heater in my office for when I get too chilly. I also run it most days in the early spring, fall and winter. The one I had crapped out, so I went to Amazon to find another one. As usual, I read quite a few reviews before I decided which one to purchase. In one of the reviews the reviewer told how he/she liked to use the heater to help reduce heating costs. They turn their heat way down and have the electric heater running next to them while watching TV. Would this make a difference in heating costs? It costs to run the heater. Doesn’t the rest of the house get uncomfortably cold? When you do turn up the heat again, doesn’t it take more energy to get it back up to where it should be?

One of my friends heats with electricity. She turns her thermostat down and then has an electric heater next to her recliner. It makes no sense to me.

We keep our thermostat at 65 year round (we don’t have central air). We never turn it up or down.

2

Would this make a difference in heating costs? It costs to run the heater.

While the electric heater does cost money to run, and is most likely more expensive to operate for the amount of heat that it generates, it’s heating a much smaller area of the house. The reduced cost of heating the rest of the house will almost always be much greater than the added cost of running the electric heater. So yes, this will reduce your overall heating costs.

Doesn’t the rest of the house get uncomfortably cold?

Yep.

When you do turn up the heat again, doesn’t it take more energy to get it back up to where it should be?

The amount of heat that your house loses is proportional to the temperature difference between the house and the outside air. The house loses less heat when the inside temperature is colder. The savings you get from letting the inside temperature drop will be greater than the extra cost of running the heating system to get the temperature back up.

A lot of folks have automatic thermostats that will reduce the temperature during the day when they are at work, then will raise the temperature up in their house just before they get home. This does result in substantial savings over keeping the temperature up all day long.

Once thing you have to be careful of is that if you have a heat pump, they will often turn on an additional electric heater when the temperature difference is too great, which is hugely inefficient compared to the heat pump. This can end up costing you money by letting the house get cold and then heating it back up. Modern heat pumps will usually have a setting on the thermostat so that the additional heat doesn’t kick on and ruin all of your savings.

Another thing that you have to watch out for is that if you let the house get too cold, your pipes can freeze and burst.

The same thing is true in the summer, when you run the air conditioning. If you let the house get hot during the day then turn on the air conditioning, you’ll save money vs. just letting the AC run all day long. The worry here is that if you live in a hot and humid area, the heat and humidity can allow mold to grow on your walls.

One of my friends heats with electricity. She turns her thermostat down and then has an electric heater next to her recliner. It makes no sense to me.

Again, it’s the cost of heating a small area vs. the cost of heating the entire house. It’s a lot less expensive to heat the smaller area.

We keep our thermostat at 65 year round (we don’t have central air). We never turn it up or down.

That’s not the most cost-efficient way of doing things. It’s also a bit on the cool side for most people. 65 degrees is the ideal temperature for a factory floor or a place where people are doing physical work. The ideal residential temperature is more around 70 to 75 or so. You’re not the only one who likes it cool, though. As long as you and everyone in your household is comfortable at that temperature, no biggie.

3

Is this the case even if the small electric heater runs continuously, being too small to heat up the whole room (assuming the room is large enough that the heater runs continuously)?

4

Most of the time, yes. I’m sure you could find an exception, but using some numbers I know off the top of my head, the furnace for my house is about 120,000 BTU and the space heater I have from Walmart is around 5,000 BTU. The furnace is much more cost efficient per BTU but the space heater is so tiny compared to the furnace that it’s not even a close comparison. Even if the heater runs continuously it’s not going to be anywhere near the cost of running the furnace, even if the furnace is only coming on intermittently.

Your house may vary, of course, but the furnace is always going to be HUGE in comparison to a space heater.

5

I cant think of a bigger waste of electricity that using an electric heater to fight the electric ari conditioning.

6

Another advantage of small, local heaters is that you can make use of radiant heat. If they’re the right design and pointed at you, they can warm your skin significantly even if the air is still cool.

7

Just to emphasize this point, there is no special cost involved in heating a house up to a warmer temperature as opposed to having done so earlier and maintaining that temperature; on the contrary, as stated, because heat loss to the outside is proportional to the temperature difference, maintaining the house at a constant warm temperature is actually the costlier option.

IOW, there seems to be some sort of myth that there’s something extra costly about running the furnace for a long time to reheat a house that’s been allowed to cool, whereas this is actually the more economical option because of cost savings during the cool period. Also, a furnace running for a long time is not going to be less efficient than one running for a short time, and may indeed be more efficient.

8

Thanks! Good stuff to know.

9

Substantial being 5% to 20%. Setting back the thermostat does help, but it’s not going to cut your bills in half.

That can be a little trickier. It’s still a net benefit, but the time when the A/C needs to cool the house back to normal is also generally the hottest time of the day (3-5 pm). That means it uses more power than it would during a cooler time of day, even if the cooling capacity is the same. That’s why the savings tend not to be as good.

There’s other factors to be aware of, such as demand metering or variable time-of-day rates. If you have a well-insulated home, it could be advantageous to over-cool or over-heat it when you’re not home so it can “float” through the more costly high-demand times. That’s generally not as feasible for poorly-insulated homes, or ones with unfavorable solar orientation.

10

That’s the theory I go by. Furnace heats to 67 degF and then turn it to 63. It has to be more efficient once everything is heated up to keep it running.