There's no insta hot electric water heater that's practical in the US (at least for showers) if that's where u are.
yeah Euro area runs on 230V AC
EDIT: apparently the standard is now 230V as of 2008
for residential, it looks like single phase is pretty much a given unless i'm missing something.... is new construction sometimes 3 phase?
anyway, let's assume i'm single phase and i am willing to sacrifice temp and/or flow rate to be fully electric & tankless. what are my options? what about special/custom configurations, like multiple units in series?
my current place is just some little house, but i have been trying to talk my family into pooling resources to move into a larger, custom home where we do some multi-generational, non traditional household thing, so looking at like 6-10 people in a "weird" ADA compliant, single story house that i would want organized such that maintenance is easy for ourselves/tradespeople (like there would probably be a mechanical room, access to electric/plumbing would be easy... almost commercial construction).
and one of the things i'm an advocate for is full electrification and maximizing efficiency within that. like if we can only shower one at a time and not run any appliances during that, or if the temps "only" go up to like 80-85° in the shower, i might be able to sell that. especially if we have like a sauna or whatever that can take the place of the "hot" shower.
The 10 year warranties really, really, really are fucking necessary (if you're seriously in it for that long) with how shitty and crazily water heaters may fuck up every 6-8 year range latest if you're lucky. Relative of plumber.
Climate change is also important and this seems like one of the largest electricity draws on the home so it’s worth focusing on it, right?
yes
Or is it best to ditch tank heaters and go tankless?
This really depends on how you plan to use the water that you heat and how many people in your house want to be able to shower in hot water simultaneously. Do you use a dishwasher? You should also factor in how cold you expect the incoming water to be. If it's already 80+F most of the year, a tankless makes more sense than if your water is always 45F because with proper insulation it's a bit easier to maintain a large tank at 120F than it is to constantly heat incoming water from 45F to 120F. Having an electric tank also lets you use a time-of-use type electrical billing plan so that you do the bulk of the water heating off-peak and still take a hot shower on-peak without paying peak prices for every watt hour put into the water you're enjoying during the on-peak interval.
If you end up getting one with a tank, get the best thermal resistivity per dollar that you can in its insulation.
That might be related, but I don't think it's a thing where I live. I was referring to power billing schemes that bill based on when peak demand occurs. In the winter, if I use electricity between 5 and 10am (times fuzzed for anonymity) it's a lot more expensive than if I use that same power "off-peak"
The rheem performance platinum proterra is a heat pump water heater. It will make the area it's in cooler as a result. is also has some sort of refrigerant in it. Are modern refrigerants eco friendly?
The energy star site lists 2 models from some brand that use CO2 I think as the refrigerant
I've been assuming that heat pump water heaters generally don't do the exchange with the room they're stored in, but with the environment outside the house, or if the owner is incredibly lucky, the water in their well or in heat exchangers buried in their yard.
Heat pump water heaters are self contained, there is no outdoor heat exchanger or fresh air intake/outlet from what I've seen. However I've heard of people creating their own fresh air intake/outlet. People also do this with dryers so that they are not exhausting conditioned air.
Exchanging heat with well water or a buried ground loop while possible, would be extremely expensive and require modifications to the well or digging out a ground loop.
Edit: Outdoor heat exchanger systems exist but the one OP posted is a self contained unit.
Any refrigerant used's impact on the atmosphere will be dwarfed by the effect of the extra electricity generation needed for a non-heat pump water heater.
Another strategy my SO and I used was replacing with a smaller tank. Less to heat is less energy. May not work for everyone, but it's an option. I take showers like I'm on a submarine myself, in and out but clean as a whistle.
To gauge environmental impact here you'll want to know how your electricity, because the biggest decision is gas vs. electric. If your electricity is better than natural gas, go with the electric. Otherwise, i'd go with the efficient gas one.
I'm all against gas, but you also can't assume your energy, if driven by fossil fuels, will get clean enough over the (most likely) 10-15 year lifespan of the water heater, either. It's all a balancing and conditions game.
Okay well then it won't matter because I can guarantee you that US electricity won't have absndoned fossil fuels in every part of the US by then.
But if your electricity comes from a big old oil-burning plant (or most coal plants), an efficient gas system will objectively be better in terms of GHG emissions, as they run those suckers 24/7 even when demand is low.
