this post was submitted on 01 Nov 2023
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There is a really, really big caveat here.
While all of this is true, and while heat pumps are definitely more efficient than gas/oil/electric heat, you MUST have a well-insulated home without drafts. If your home is not well insulated, or is drafty, then heat pumps likely will not keep your home at a comfortable temperature.
A standard furnace works by kicking on when heat drops below the set point of your thermostat, and then it blasts heated air until the whole space is a certain temperature above the set point on your thermostat, and then shuts off. The most efficient heat pumps are constantly trickling a little heat at a time, rather than cycling on and off. If your home is poorly insulated or drafty, then you can end up losing heat faster than the heat pump can bring it in. The better your insulation and the better sealed your home is, the better your results with a heat pump will be.
Unfortunately, my home is largely uninsulated and pretty drafty; without doing a pretty significant amount of work, at a fairly steep cost, I can't retrofit to a heat pump.
This is my first comment, but since it's my job might as well:
The fact that you need a well insulated house for a heat pump is absolutely not true. What you need is a house where the expected heat loss at the design temperature can be added to the house using low temperature heating such as in floor heating. You can live in a cardboard box for all intends and purposes, if you can keep your house warm with (loads of) 35-40C water you are fine. And you would be amazed how much heat in floor heating can provide when having tubes at 10cm heart to heart distance from each other. Your energy bill will be enormous, but it would be as well if you would burn gas in a stove.
Does insulation help? Obviously. The most energy efficient, sustainable and comfortable kWh of heat is the one you don't need. Is it a requirement? Absolutely not.
Source, ex aerospace engineer that advices and installs heat pumps for residential buildings
Edit: This might differ across the pond but in the Netherlands in floor heating is super common. In America I believe this is not so much the case? Not sure.
So does a heat pump, and you can get Air to Water heat pumps that work almost exactly as a furnace.
Our stoker wood pellet furnace does the same if possible, it can't go below 25% capacity, because it doesn't burn right at lower capacities. So at certain temperatures, it maintains a steady state, but at others it has to turn on and off. A heat pump can easily do whatever is more efficient.
PS:
Heat pumps are similar technology to fridges, which also turn on and off depending on needs.
what does insulation have to do with heat pumps?
heat energy is heat energy, where you get it from doesn't matter, if your house isn't well insulated the heat loss will be the same regardless what pumps in the heat.
The home is a container for heat. If it is a poorly insulated container the heat pump does not put out enough BTUs to keep the house warm because the heat is escaping faster than it can be generated.
If that's the case, you simply installed a heat pump with too little capacity...
Heatpumps come in all sizes... I just looked up one that outputs 50 kW worth of heat, and if that isn't enough you can integrate up to 16 of them to output a total of 800 kW of heat.
That being said, if your house is badly insulated and drafty, you should fix that first, it will immediately cut your heating bill, no matter which heat source you use.
It seems to me like you're describing the genetic problem of having an undersized heating system, not anything specific to heat pumps. I'm positive heat pumps exist that are equal in capacity to whatever furnace you have.
It does sound like in your case improving your house's insulation would be a better investment than installing a new heating system though.