I know that a heat pump is cheaper to operate than an electric space heater, but I'm wondering if a heat pump will heat our home faster than an electric space heater.

I'm asking because I have an open-plan two-storey home, and I've been frustrated because neither our single baseboard heater nor our two space heaters are enough to get our main (lower) floor tolerably warm - it takes hours to bring the place up from 53°F to 64°F. I've heard about the cost savings of heat pumps, but am wondering if they too will take hours to heat up 1250 sq ft.

Part of me doubts that the heat pump will be any faster, because an electric space heater is essentially a fan in front of a heat source. But isn't a heat pump also basically a fan in front of a heat source?

Or is the heat pump heat source so much hotter and the fan so much more powerful that it will heat our home faster? For example, one of the bigger heat pumps that can heat 1250 sq ft?

I've never seen/felt a heat pump in action, so I'm asking here.

  • i think that you are referring to forced air heating ... heat pump is a reverse air conditioner. it takes heat from the outside and moves it to the inside of the house, usually it is a reversible central air conditioner that is attached to the forced air furnace. ... in summer it cools your house and in winter it heats your house. .... it could also be geo-thermal.
    – jsotola
    Commented Dec 22, 2017 at 6:29
  • 1
    We need to know a lot more about your house, the insulation lever in the house, where you live, what kind of heat system does the house have now?
    – Paul Logan
    Commented Dec 22, 2017 at 6:51
  • If you want fast hot heat fossil fuel is hard to beat.
    – Paul Logan
    Commented Dec 22, 2017 at 6:53
  • The capacity of the heater (expressed in BTU/h or in kW) is the relevant property that determines how fast the temperature will rise and what temperature difference the system can maintain with the outside for a given structure. Where are you located? What "size" heating system are you considering? In our 1-story 2050 sq ft house in Dallas our 85,000 BTU/h NG fired central forced-air furnace is just fine. Our a/c is rated at 42,000 BTU/h and is barely adequate. To put it mildly, the insulation in our attic needs upgrading. Commented Dec 22, 2017 at 11:33
  • Speed kills, energy wise. Modern systems are designed to be used with a thermostat that regulates temperature over time. "Setback" type thermostats let the user program desired temperatures for different times, days, seasons, etc. Since efficiency seems to be an important feature for you, you should focus on the most efficient method for your space characteristics, then regulate for a comfortable temperature. If you want it to be warm at a certain time, program your thermostat so that it brings the space to that temperature before then, no need for speed. Commented Dec 22, 2017 at 16:21

4 Answers 4


The answer depends on size of the space heater vs heat pump. If they are set same size in BTU they will take the same amount of time and the heat pump will cost much less. If you double the size of the heat pump compared to the space heater the heat pump now will heat much faster at a similar cost to the space heater type system.

  • 1
    For a GOOD heat pump in the current era, that's more like "triple" (look for a COP of 3.0 or better - don't settle for 2.0, it will cost you in the long run.)
    – Ecnerwal
    Commented Dec 22, 2017 at 20:22
  • @Ed Beal: That's a nice simple explanation. Do you know how many BTU would be put out by my 7' electric baseboard heater? A typical ductless mini-split heat pump size is 12,000 BTU. Commented Dec 23, 2017 at 7:32

BTUs are BTUs no matter where they come from.

So a 50,000 BTU heater will be the same no matter what the fuel is.

The difference is, a heat pump has a coefficient of production of 3 or more. Which means for every Kilowatt of electricity put into a resistive heater, you would get three times the heat from a heat pump.

I would NEVER try to heat a house with resistive heat unless I owned the power company.

There is a reason why resistive heaters are cheap to buy....because they are expensive to run.

Spend the money and go full on with a geothermal heat pump. You will not regret it.

Good luck!

  • Some earth source heat pumps in Dallas have failed due to the wells being improperly sized or placed too close together. What has happened is that the ground gains so much heat in our long cooling season that the ground temperature around the pipes rises gradually over the first year or two of operation so the heat pump loses capacity for cooling. I think you have to be careful about getting an earth source heat pump. These are very expensive initially and improvements have continued to be made in the standard air source heat pumps. Commented Dec 22, 2017 at 20:31
  • Except when they are BTUs/hr, which is not the same thing at all. Commented Dec 22, 2017 at 22:44
  • @ArchonOSX Good point about coefficient of production. So I can hopefully expect the heat pump to be a lot hotter than the electric baseboard. Commented Dec 23, 2017 at 7:36
  • No, not hotter. It will just produce the same amount of heat for less money. If it takes 50,000 BTUSs per hour to heat your home, it will cost you three times as much to heat that home with electric resistive heat than with a heat pump. The temperature is the same.
    – ArchonOSX
    Commented Dec 23, 2017 at 23:09
  • @JimStewart I installed an open loop heat pump with a single well and just dump the water out onto the ground after extracting the heat. Saves on a second well and you don't have the problem you cited. They could also install a closed loop pipe system in Dallas instead of two wells.
    – ArchonOSX
    Commented Dec 23, 2017 at 23:12

First, don't get confused by power spent vs power gained. Heat pumps move energy around, so it's possible for a 5000W heat pump to move 15,000W of useful heat.

Second, don't get confused by

  • power (rate of flow right now, e.g. 5000 watts or 20,000 BTU**/hour**; 1 watt = 3.412 BTU/hr) versus
  • accumulated energy (flow x time, e.g. 5 kilowatt-hours or 20,000 BTU, 1 kwh=3412 BTU).

Worse, "BTU" in many contexts actually means "BTU/hr", e.g. In the spec for furnaces.

When you're near your desired temperature, your house loses energy to the outside at a certain rate (i.e. power) depending on outside temperature.

Suppose you lose 3000 watts through leaks through your insulation. OK, if your heating is 4000 watts, you can see where you're only gaining 1000W/hr and this is gonna be a slow run. Increase heating to 5000 watts and your net heating doubles and the time cuts in half. Or improve insulation 33%, same effect.

The upshot is that if you want speed, you wants lots of immediate power: lots of watts of heat generated, or BTU/hr.

Jimmy Fix-it makes the point that you don't want speed. I don't see why not. He's talking about the additional infrastructure costs of installing more heating capacity. Okay. But if you like to change temperatures, a system that can do this quickly saves money over doing it slowly. If you are using a predicting smart 'stat, better to have it kick 30 minutes in advance than 3 hours, because that's 2.5 hours of thermal loss you won't have.

If you're all-electric, you are partly limited by a) your service's ability to supply power, b) your wires' ability to carry it, and c) your ability to pay a fat heating bill.

With that in mind, heat pumps are much more efficient at turning watts you pay for into watts that warm your house. In the above scenario you replace your 5000W heater with a 5000W (consumed) heat pump. It will bring into the house 10,000-15,000W (pumped). Now instead of gaining 2000W, you are gaining 7000-12,000W. Which means your house warms 3-6 times faster!

Heat pumps do have an Achilles' heel. They don't work if the outside air source is too cold. Did I say air? Why are we talking about air? If you dig a hole deep enough, the ground never freezes. At very diggable depths, things are quite temperate, e.g. 55 degrees all year. Well water is like that. This is an ideal temperature for heat pumps to work both for heating and cooling, and you gain even more efficiency. So a perfect situation is the ground-sourced heat pump, where it's operating from groundwater, a coolant loop dug deep enough into the earth, etc.

However if you can't ground-source your heat pumps, then you need to contend with a nightmare scenario of the outside air being too cold for the heat pump to work at all. This is less of a problem in better, newer units. In that case, the system "fails over" to resistance heating, exactly what you have now, and the electricity cost can hurt!

There is one way around that "nightmare scenario" but it's very trailer-park. Build an insulated structure over your outside heat pump unit, so it's "inside a building". Heat the interior of that building with fuel of some kind. It will need to be a BIG heater, since it's heating your whole house via the heat pump. Now the outside unit will be in good temperatures for it to work, but you'll have a fuel bill. "But that sounds terribly inefficient" sure, it's a hack to use a few days a year. On the other hand, institutional sites do pretty much this, with heat pumps all over the institution sourcing to service water which runs all over the complex. In winter, they pre-heat the service water to about 70F. So it's not that extreme or bizarre.

If you don't want ugly air ducts all over your house, they make "mini-split" units that run thin, concealable freon pipes around your house instead. This also lets you zone your heating and A/C. All heat pumps come with A/C.


You live in a climate that could effectively benefit from the mini-split system. They are pricey but effective. I doubt you need air condition much of the year, bad for mini-split. I am a big believer in fossil fuel it it is available. There all all kinds of wall heaters that burn FF. And create a ton of heat for the price.

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