How can I update an old electric furnace in my mobile home? [closed]

Question

I rent a small one-bedroom trailer with an old electric furnace from the 70s. My electric bills in the winter are insane, especially relative to the size of the space.

My suspicion is that the main problem is either the inefficiency of the furnace or holes in the duct system (or both). I live in the south, so it doesn’t get that cold, and I run a window AC unit all summer at a fraction of the cost, so I don’t think it’s a draft or insulation issue.

The other complication is that I have a cat, so I have to run the heat when I’m out if it’s going to get below 45° or so. I keep it as low as I can, but the furnace doesn’t even turn on if I set it below 65°. I honestly think a space heater would be more cost-effective, but that seems like a massive fire hazard if I’m not home, especially with a cat.

Does anyone have any ideas for a more cost-effective way of heating my trailer? Or are high electric bills in the winter just the price I pay for low rent? I’m considering getting an electric radiator at the moment, but open to all suggestions.

Answer 1

You can get a heated pet bed for the cat, and turn off your heat entirely while you are away. These are very low wattage and they don't feel warm to the touch, but once a dog or cat lies on it, the warmth becomes apparent. Not convinced? You can put one on your couch and sit on it for a few minutes to feel what the cat would feel.

Answer 2

Replace the window AC with a heat pump and run it for heat. Make sure the installation is draft free and well-insulated. Heat pumps are (ideally) several times more efficient than resistance heat.

You can buy a smaller unit (without built-in electric heat, which generally requires a 240 V outlet) since you already have fallback resistance heating. Set the furnace 5 degrees under the window unit's setpoint, so it's automatic.

Answer 3

All electric heat is 100% efficient by definition, because of the way physics works. So getting electric heat from one box vs another box isn't going to do anything at all.

Thus, it's a fool's errand to use dangerous space heaters which are specifically listed as Not To Be Run Unattended (while you are away or asleep). Also those space heaters are expensive compared to their durability. I find we have to replace them yearly or more. Soon we have paid for a window heat pump.

Your #4 threat is a broken thermostat that doesn't allow your heat to run below 65F. Many cheap thermostats don't go below 50F, but you certainly ought to be able to go to 50F. Thermostats are cheap. The #3 threat is poor insulation of the building. The #2 threat to your energy bill is, as you say, leaky or broken ducts. Now we're talking about maintenance, repairs and upgrades - and you'll have to figure out politically whether that makes sense for you as a tenant to fix somebody else's building.

The #1 threat is a refusal to use the "physics cheat code" known as a Heat Pump. You can hardly be blamed for not knowing about this; it's really new in the North American consciousness, even though we've doing it one-way for 70 years now. This is what heat pumps are and how they work. TLDW: they're air conditioners with a reversing valve added so they can heat the inside and cool the outside on command. And they work better than you've heard in places like Chicago.

So as user71659 says, you'd be well-advised to consider "window unit" heat pumps - they look like window air conditioners and you can take them when you move out. In fact, they are window air conditioners with the reversing valve added.