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Reservoir: Smart electric water heater

reservoirhome.com

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Re: Reservoir: Smart electric water heater

#61

Post by kenmacd »

phil21 wrote: post #23

The best investment in my comfort and upgrading my home was two redundantly configured Navien continuous water heaters. Never worry about running out of hot water ever again. If I’m gone on a trip for 2 weeks my hot water bill is zero. Due to having overcapacity, whenever I have guests staying with me no one ever has to worry about simultaneously using showers or any other hot water at all. I run out of water pressur…

> If I’m gone on a trip for 2 weeks my hot water bill is zero

You mention other advantages, but money isn't one. You're limited to 100% efficiency with tankless.

Although an idle hot water tank can waste ~70W (~1.7kWh) of power, this is way more than made up for by using a heat pump. Plus tankless strains the grid a lot more than any system with a buffer built in.

Re: Reservoir: Smart electric water heater

#62

Post by kenmacd »

elcomet wrote: post #8

The heat pump will pull heat from inside the house? This sounds terrible for efficiency in winter, as you will need to reheat the room

There are systems (like the sanco2) that use an indoor/outdoor pump.

> This sounds terrible for efficiency in winter, as you will need to reheat the room

Sure, but lots of people have some point of the year they want cooling.

Even during the heating season it's only worse if you're heating the living space with something _worse_ than what you're using to heat the hot water. If you have a heat pump for room heat then you're moving heat from outside, to in the house, to in the water heater.

If you're heating the room with electric then in the winter it's no different than using an electric water heater (100% efficient).

Re: Reservoir: Smart electric water heater

#64

Post by phil21 »

p1esk wrote: post #31
phil21 wrote: post #23

The best investment in my comfort and upgrading my home was two redundantly configured Navien continuous water heaters. Never worry about running out of hot water ever again. If I’m gone on a trip for 2 weeks my hot water bill is zero. Due to having overcapacity, whenever I have guests staying with me no one ever has to worry about simultaneously using showers or any other hot water at all. I run out of water pressur…

Two reasons I decided not to go with tankless: 1. Can’t have recirculation pump to supply hot water instantly throughout the whole house. 2. Significantly higher energy bill compared to heat pump. An additional bonus is the heat pump cools my garage in the summer.

Recirculating works fine with these, if I chose to do it. They both have a tiny hyper-heated insulated tank for the purpose so they can trickle a hot water loop to the furthest destination. They also have a recirc mode which would barely show up on your monthly energy bill.

If I was building new construction I’d do it, but the upgrade just isn’t worth it for me at the moment since it would require drywall repair and running another return line for relatively minimal benefit.

Note as others have pointed out: this setup is not to save money, it’s entirely quality of life as the primary metric under consideration.

Re: Reservoir: Smart electric water heater

#65

Post by yencabulator »

jfim wrote: post #10
elcomet wrote: post #7

Earlier quoted context omitted.

Yeah this sounds disingenuous. I can also see my heater to 70C if I want, that does not increase its size...

It is a scalding hazard though. At 70°C skin burns occur in about a second or so. The thermostatic valve makes it so that the water that comes out of the water heater is at a more reasonable temperature.

Then again, I grew up with thermostatic valves in the shower mixer, and a "child safety" latch to restrict it to even less hot water in normal use. I don't see why putting the mixer in the water heater is that different.
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