4 ms·

What about electric water heaters? I am unfamiliar with the usage patterns and losses over time, but having my home water heater having some variability in temp

What about electric water heaters? I am unfamiliar with the usage patterns and losses over time, but having my home water heater having some variability in temperature would be ok with me — I’d simply adjust the handle in the shower.

rocqua 6y ago
Colleagues of mine are working on a system using these kinds of water heaters. Specifically, they are working for a standardized protocol to allow these devices to negotiate prices / indicate to the grid how much they could take. From what I heard they said something like a half-time for the heat in these devices of about 1 to 2 days.
- Scoundreller 6y ago
  Could do the same with freezers. And maybe a few degrees with fridges. And boost those with phase-change materials at the right thaw points.
cmurphycode 6y ago
With a properly installed thermostatic mixing valve, you don't even need that. The water will always exit at a safe, constant-ish temperature regardless of the water temperature in the heater, by mixing in the cold supply.
scottlamb 6y ago
Interesting idea. It'd have to be done carefully because there are problems with going too cold or too hot: * Too cold: Legionnaire's disease. Presumably not right away, so maybe there's some wiggle room if you're careful about timing. * Too hot: scalding, particularly if you have kids. Maybe a new design could have a thermostatic valve on the output to give more flexibility.
- abe_m 6y ago
  Thermostatic valves are common in institutional water heating installations. There are also quite a few people who use thermal storage with wood fired boilers. The boilers burn the most efficient and cleanest when they are near full output, then hot water is stored in an insulated tank to intermittently supply the house with heat. Description of one such system: https://www.newhorizoncorp.com/PDF/ekomanual.pdf https://www.newhorizoncorp.com/PDF/ekomanual.pdf

rocqua 6y ago

Colleagues of mine are working on a system using these kinds of water heaters. Specifically, they are working for a standardized protocol to allow these devices to negotiate prices / indicate to the grid how much they could take. From what I heard they said something like a half-time for the heat in these devices of about 1 to 2 days.

Scoundreller 6y ago
Could do the same with freezers. And maybe a few degrees with fridges. And boost those with phase-change materials at the right thaw points.

cmurphycode 6y ago

With a properly installed thermostatic mixing valve, you don't even need that. The water will always exit at a safe, constant-ish temperature regardless of the water temperature in the heater, by mixing in the cold supply.

scottlamb 6y ago

Interesting idea. It'd have to be done carefully because there are problems with going too cold or too hot: * Too cold: Legionnaire's disease. Presumably not right away, so maybe there's some wiggle room if you're careful about timing. * Too hot: scalding, particularly if you have kids. Maybe a new design could have a thermostatic valve on the output to give more flexibility.

abe_m 6y ago
Thermostatic valves are common in institutional water heating installations. There are also quite a few people who use thermal storage with wood fired boilers. The boilers burn the most efficient and cleanest when they are near full output, then hot water is stored in an insulated tank to intermittently supply the house with heat. Description of one such system: https://www.newhorizoncorp.com/PDF/ekomanual.pdf https://www.newhorizoncorp.com/PDF/ekomanual.pdf