Is it cheaper to use a plug-in oil radiator to heat an individual room, or run the central heater to heat an individual room and living room?
With winter coming up, I have two options for home heating.
Central unit
I can use the central unit and close/open vents throughout the house to heat up only the individual rooms I want. This would heat up rooms very quickly. However, to make this work, the living room with the thermostat will also need to be heated so that the thermostat reads the proper temperature. The living room is by far the largest space at about 2.5 times the size of the largest room.
Oil-filled radiator
I can use an oil-filled radiator to heat up an individual room. This would be much slower, but I wouldn't have to heat up the entire living room. However, the oil-filled heater might not be as efficient as the central unit. I don't know. I plan to rarely heat up the living, no more than once per month.
Just an FYI, closing up vents in an hvac can actually cause problems. It puts more strain on the fan unit, which can cause it to burn up quicker. The unit is designed to move a certain amount of air, if you restrict that air, pressure builds up in the system.
A couple closed over an entire system is fine, but closing all but one room would definitely cause problems.
Depends on the unit and whether it was over sized or under sized for the space, but restricting 60â„… air flow is a lot.
Another thing to consider is that if you later want to heat up the entire house, the unit has to work harder. Sometimes it can be more efficient to just keep the house close to your target temp.
Depends on the unit and whether it was over sized or under sized for the space, but restricting 60â„… air flow is a lot.
Thanks for your response! I appreciate it. Do you know how I can investigate this further? I would like to figure out if I'm over-stressing my unit because I've been doing that for the past ~2 years.
Another thing to consider is that if you later want to heat up the entire house, the unit has to work harder. Sometimes it can be more efficient to just keep the house close to your target temp.
Heating up the house happens so rarely that I can't remember the last time I did that. It may have been ~2 years.
I'm not an HVAC technician so I wouldn't know exactly, but I think there's two things to consider: static pressure and duty cycle. Static pressure is the fan working hard to spin which causes wear on bearings. Duty cycle is how long the machine runs. If your duty cycle is too low then the machine is turning on and off quickly which is bad.
You could look at the size of the unit and there's some rules of thumb that translate size, climate, and square footage of just the areas you leave the vent open and there are online calculators you can use.
I think the only way to know for sure is to measure the pressure drop across the intake and outflow and see what the fan motor is rated for.
Another good way to do it is to actually hire a HVAC individual on and have them come out and just look at the system. But be wary of that. Some of them are not exactly the most brightest bulbs in the world. And they will tell you, oh you have to have them all open at the same time you can’t close them. Without actually looking at the system. I’ve run into that to myself. In my house, I can close, almost half of my vents without any issue, and yet a number of techs have told me I can’t do that. Until I make them go and look at the furnace and count the number of vents and look at the size the vents then they go oh yeah, I guess you can.
Like I said some of them are not very bright. So maybe it might pay to hire on a couple of them to really look it over. Make sure they really look at the central system, blower furnace, etc. and then also look at the vents in the size of the vents.
Yes, it cost some money upfront for them to come out and help you with it, but you can get an idea of to what they’re doing.
The other option is to go down to the library and check out a bunch of books on the subject and try to learn it yourself.