The Biden administration is tightening efficiency rules for water heaters, stoves and other appliances, and conservative politicians are dialing up their criticisms.
As discussed in section II.B.3, DOE is finalizing standards for all consumer water heaters, with the exception of gas-fired instantaneous water heaters, in this Final Rule.
So there has been no change to the rules for tankless heaters.
Extreme energy use for pretty low deltas on temperature. Best possible efficiency is 100%, far less than the 2.5+ cop a heat pump unit will get you. If it’s at all manageable, get the heat pump.
Frankly, their inefficiency means the emissions they cause are still pretty bad unless you know your energy source is more renewable than most.
But they don’t need venting, which is nice. They do take a big fat electrical connection though - the one I installed was two 2 pole 40a breakers - hopefully you have at least 200A service. Mostly they work as intended.
Thanks. That makes sense. We installed a gas tankless after looking into electric tankless. The lack of venting looked really attractive until I blanched at the wiring we’d need to pull.
My experience with tanked electrics was that they take a long time to recover. Is this also true of heat-pump based tanked WHs?
We switched to an externally mounted tankless when our big ole water heater conked out. It’s way more energy efficient, but everyone has to run the water for a good minute until it kicks in and makes it through the pipes
I’ll look into a heat pump once this one dies, but running water during a drought is just wrong.
Hmm, I couldn’t find anything about tankless heaters. I absolutely love that I never run out of hot water, especially after my wife takes her shower.
Per the actual rule:
So there has been no change to the rules for tankless heaters.
Believe It or not there are electrical tankless heaters. I actually installed one not too long ago because it made sense in a very odd application.
Mostly they’re a terrible idea though.
Yeah, they’re pretty rare and almost never the best option. I don’t think I’ve actually encountered one.
We’ve considered switching to an electric tankless WH. What makes them a poor choice?
Extreme energy use for pretty low deltas on temperature. Best possible efficiency is 100%, far less than the 2.5+ cop a heat pump unit will get you. If it’s at all manageable, get the heat pump.
Frankly, their inefficiency means the emissions they cause are still pretty bad unless you know your energy source is more renewable than most.
But they don’t need venting, which is nice. They do take a big fat electrical connection though - the one I installed was two 2 pole 40a breakers - hopefully you have at least 200A service. Mostly they work as intended.
Thanks. That makes sense. We installed a gas tankless after looking into electric tankless. The lack of venting looked really attractive until I blanched at the wiring we’d need to pull. My experience with tanked electrics was that they take a long time to recover. Is this also true of heat-pump based tanked WHs?
Most of them are actually coal fired.
Is that because they were already efficient or because they can’t reasonably be made more sense efficient?
I would assume both. They transfer basically all the heat generated into the water and only heat when water is being used.
We switched to an externally mounted tankless when our big ole water heater conked out. It’s way more energy efficient, but everyone has to run the water for a good minute until it kicks in and makes it through the pipes
I’ll look into a heat pump once this one dies, but running water during a drought is just wrong.
This Old House has episodes where they have a small recirculation pump to keep lines primed with warm water.
This kills the efficiency gain of not keeping a hot tank though.