Most electric heat pump hot water heaters have a slow-mode which uses the heat pump, and fills a large tank with hot water, and a fast-mode which uses a resistive heater when the tank runs out. I don’t see why this situation is particularly different for larger buildings, except that they need a larger tank and an electrical supply which can deliver the needed wattage.
Cheapo landlord could of course install an undersized unit, as they can with any other key system.
It still amounts to “I’m heating up a big tank of water and supplying it to people on an as-needed basis.” The article makes it clear that they’re using several to supply the whole building:
Electric water boilers | These provide hot water for the building and are typically more energy efficient than gas boilers, which are common in New York City.
Fair enough. I guess there could be a time when they need resistive to augment that but I’d think with sufficient boiler capacity you could do only heat pump.
Most electric heat pump hot water heaters have a slow-mode which uses the heat pump, and fills a large tank with hot water, and a fast-mode which uses a resistive heater when the tank runs out. I don’t see why this situation is particularly different for larger buildings, except that they need a larger tank and an electrical supply which can deliver the needed wattage.
Cheapo landlord could of course install an undersized unit, as they can with any other key system.
Big buildings like this usually use a central boiler. I’d be shocked if they weren’t.
It still amounts to “I’m heating up a big tank of water and supplying it to people on an as-needed basis.” The article makes it clear that they’re using several to supply the whole building:
Fair enough. I guess there could be a time when they need resistive to augment that but I’d think with sufficient boiler capacity you could do only heat pump.
You definitely can do only heat pump, but adding resistive backup is cheap if you’re already putting in new wiring anyways. So people do.