Yes, but water heater tanks are by themselves inefficient as it stores heated water regardless of it being used.

If I ever get a house (millennial lol) I’d want to have a tankless water heater. That way supply meets demand exactly.

If I ever get a house (millennial lol) I’d want to have a tankless water heater. That way supply meets demand exactly.

Tankless is crazy LESS energy efficient than a tank heat pump water heater. Why? In tankless you’re having to CREATE THE HEAT. With heat pump tank you don’t. You’re citing the inefficiency of storing a tank of hot water, but the insulation on a decent (not garbage) hot water heater is really really good! The heat loss through the insulation is VERY small. You could turn off the water heater entirely and come back days or possibly weeks later and the water is still hot.

You still have to create the heat for a water tank, too …

A heat pump pulls heat from the ambient air and accumulates it in the tank, unlike a conventional water heater which uses combustion or a resistance heater to generate the heat from an energy source. That is why heat pumps are generally much more efficient than other types of water Heaters, including on-demand Heaters which have a very high instantaneous load.

Heat pumps do have their weaknesses though, specifically they lose efficiency the colder the ambient temperature is, so if you live in the arctic circle this might not be the technology for you.

Heat pumps lose efficiency far above arctic temperatures. Below 40F, the efficiency drops quickly. Also, a heat pump water heater doesn’t do all the heating itself. It still uses an electric coil to get to the desired temps.

I personally would like to switch to on demand due to the space savings. Having a tank take up space in my garage is annoying.

Yes we actually can’t even run our heat pump mini-split below 40, it runs too many defrost cycles and can’t heat the room. We installed a wood pellet stove to use for those temps.

Wow, what model do you have?

It’s a Carrier 40MAHB

Ah… what about the outdoor unit? Do you have a high heat model?

It’s a Carrier 38MARB Performance Heat Pump, and it SAYS it’s rated at 100% efficiency down to 5 deg F but I can tell you from experience that it starts buckling below freezing. I have monitored it over a whole winter season and when we hit the 20s it starts running defrost cycles every 15-20 minutes. Each cycle takes about 5-10 minutes to defrost. It’s not able to keep the room warm.

Granted, this is a 500 sq ft room with an wide opening to the next room and a 25’ ceiling. I don’t think it was a great use-case for heating in general. For cooling, this thing is irreplaceable. It barely breaks a sweat and uses almost no energy, while keeping the room at any low temperature I set it to. I’ve yet to see it have any issues cooling, even when it’s 90F and humid outside.

Good info… thanks. It doesn’t look like 38MARB is is a “high heat” model. R stands for Regular Heat. You could look at 38MGHBQ. The H is for High Heat.

That aside, there seems to be a lot of overhyping the performance of heat pumps lately. I have been interested in one, but am hesitant. Around me there are rebates to replace your furnace with a heat pump, but I don’t like the idea that they become less capable of heating the colder it gets. At least a furnace generates the same amount of heat when it is cold.