6 ms·

It's funny how removed we are from reality. Even if $15/month might be cheaper than a propane bill, it would be far far more expensive against the planet to hea

It's funny how removed we are from reality. Even if $15/month might be cheaper than a propane bill, it would be far far more expensive against the planet to heat it with gas/coal burned at a factory 100 miles away, converted to electricity, then converted back to heat inside the spa water heater.

wrycoder 5y ago
I think that an air/water heat pump on the tub, with say a COP of 8, would be less expensive to operate than propane or straight electric. But, I couldn't justify the capital expense. (Small hot tubs are electric.) I like my wood/propane mix for heating, because it's immune to power outages. At some point I'll get too old to cut/split/haul wood, though, and will have to figure something else out. I'm not sure why there's a push to eliminate gas cooking in favor of electricity. Perhaps some people are concerned with methane leaks in the natural gas distribution system.
- ryukafalz 5y ago
  > I'm not sure why there's a push to eliminate gas cooking in favor of electricity. Perhaps some people are concerned with methane leaks in the natural gas distribution system. It's that, as well as the fact that having a gas stove means you have a gas hookup in the first place, so you're more likely to also use it for heating. That in turn leads to more emissions than other heating methods produce.
  - wrycoder 5y ago
    Well, even with a catalyst, my wood stove puts out a lot of emissions. But, I don't live in an area with an inversion layer.
- danans 5y ago
  > I'm not sure why there's a push to eliminate gas cooking in favor of electricity. It can make a lot of sense in urban areas. In addition to removing the methane leaks (with their high GWP), it reduces the need to install/maintain expensive natural gas distribution infrastructure, and also improves indoor air quality by eliminating NO2 and CO production within the house. If the power goes out, you just use a propane grill in the backyard, or a small butane stove.
- nybble41 5y ago
  > Small hot tubs are electric. S̶p̶e̶c̶i̶f̶i̶c̶a̶l̶l̶y̶,̶ ̶f̶o̶r̶ ̶t̶h̶o̶s̶e̶ ̶w̶h̶o̶ ̶w̶e̶r̶e̶n̶'̶t̶ ̶a̶w̶a̶r̶e̶,̶ ̶s̶m̶a̶l̶l̶ ̶h̶o̶t̶ ̶t̶u̶b̶s̶ ̶a̶r̶e̶ ̶t̶y̶p̶i̶c̶a̶l̶l̶y̶ ̶h̶e̶a̶t̶e̶d̶ ̶t̶h̶r̶o̶u̶g̶h̶ ̶f̶r̶i̶c̶t̶i̶o̶n̶ ̶a̶n̶d̶ ̶w̶a̶s̶t̶e̶ ̶h̶e̶a̶t̶ ̶f̶r̶o̶m̶ ̶t̶h̶e̶ ̶c̶i̶r̶c̶u̶l̶a̶t̶i̶o̶n̶ ̶p̶u̶m̶p̶s̶ ̶a̶n̶d̶ ̶d̶o̶n̶'̶t̶ ̶h̶a̶v̶e̶ ̶d̶e̶d̶i̶c̶a̶t̶e̶d̶ ̶w̶a̶t̶e̶r̶ ̶h̶e̶a̶t̶e̶r̶s̶.̶ ̶Y̶o̶u̶ ̶c̶o̶u̶l̶d̶ ̶a̶d̶d̶ ̶a̶ ̶s̶e̶p̶a̶r̶a̶t̶e̶,̶ ̶m̶o̶r̶e̶ ̶e̶f̶f̶i̶c̶i̶e̶n̶t̶,̶ ̶w̶a̶t̶e̶r̶ ̶h̶e̶a̶t̶e̶r̶ ̶a̶n̶d̶ ̶r̶u̶n̶ ̶t̶h̶e̶ ̶p̶u̶m̶p̶s̶ ̶l̶e̶s̶s̶ ̶o̶f̶t̶e̶n̶,̶ ̶b̶u̶t̶ ̶i̶t̶'̶s̶ ̶n̶o̶t̶ ̶a̶s̶ ̶s̶i̶m̶p̶l̶e̶ ̶a̶s̶ ̶r̶e̶p̶l̶a̶c̶i̶n̶g̶ ̶o̶n̶e̶ ̶k̶i̶n̶d̶ ̶o̶f̶ ̶h̶e̶a̶t̶e̶r̶ ̶w̶i̶t̶h̶ ̶a̶n̶o̶t̶h̶e̶r̶.̶ Never mind. Apparently I was misinformed. The circulation pump moves the water through the heater, but isn't the primary heat source.
  - nkurz 5y ago
    I don't think this is true. Could you source this? I've had several small outdoor electric hot tubs, and all of them have had dedicated heaters. The couple times I've had problems with the heater, the symptoms involved the pump running constantly and the tub never reaching temp. I'm sure there is some friction heating, but I don't think it's anywhere near enough to reach standard temperature.
    - nybble41 5y ago
      Apparently you're correct, and I was misinformed. You could implement it this way—like how Tesla's newer designs can run the electric motor in a less-efficient mode to provide heat for the battery pack—but the designs I investigated did have separate heaters as part of the circulation system. (For some reason the specs for these were not listed in the product summary, but rather only in the manual.)
- sbradford26 5y ago
  So in NH I am paying just over $4.20 a gallon for propane and about $0.18 a kwh for electricity. With those prices a propane heater for my hot tub would cost more to run. Also a heat pump heater for the hot tub would optimistically get around a 3-4 COP in warmer weather and 2-3 in the colder weather but either of those would lower your price to heat it considerably but the capital expenses neglect those savings. Source: https://www.amsenergy.com/fuel-cost-calculator/ https://www.amsenergy.com/fuel-cost-calculator/
  - wrycoder 5y ago
    Interesting, thanks. Looks like burning shelled corn is the way to go. Or coal.
throwaway48375 5y ago
That area is almost exclusively hydroelectric power.
- wrycoder 5y ago
  Er, which area is that? NH is almost entirely nuclear from the Seabrook site.
  - throwaway48375 5y ago
    I just skimmed the article, but I thought it said it was in BC.

wrycoder 5y ago

I think that an air/water heat pump on the tub, with say a COP of 8, would be less expensive to operate than propane or straight electric. But, I couldn't justify the capital expense. (Small hot tubs are electric.) I like my wood/propane mix for heating, because it's immune to power outages. At some point I'll get too old to cut/split/haul wood, though, and will have to figure something else out. I'm not sure why there's a push to eliminate gas cooking in favor of electricity. Perhaps some people are concerned with methane leaks in the natural gas distribution system.

ryukafalz 5y ago
> I'm not sure why there's a push to eliminate gas cooking in favor of electricity. Perhaps some people are concerned with methane leaks in the natural gas distribution system. It's that, as well as the fact that having a gas stove means you have a gas hookup in the first place, so you're more likely to also use it for heating. That in turn leads to more emissions than other heating methods produce.
- wrycoder 5y ago
  Well, even with a catalyst, my wood stove puts out a lot of emissions. But, I don't live in an area with an inversion layer.
danans 5y ago
> I'm not sure why there's a push to eliminate gas cooking in favor of electricity. It can make a lot of sense in urban areas. In addition to removing the methane leaks (with their high GWP), it reduces the need to install/maintain expensive natural gas distribution infrastructure, and also improves indoor air quality by eliminating NO2 and CO production within the house. If the power goes out, you just use a propane grill in the backyard, or a small butane stove.
nybble41 5y ago
> Small hot tubs are electric. S̶p̶e̶c̶i̶f̶i̶c̶a̶l̶l̶y̶,̶ ̶f̶o̶r̶ ̶t̶h̶o̶s̶e̶ ̶w̶h̶o̶ ̶w̶e̶r̶e̶n̶'̶t̶ ̶a̶w̶a̶r̶e̶,̶ ̶s̶m̶a̶l̶l̶ ̶h̶o̶t̶ ̶t̶u̶b̶s̶ ̶a̶r̶e̶ ̶t̶y̶p̶i̶c̶a̶l̶l̶y̶ ̶h̶e̶a̶t̶e̶d̶ ̶t̶h̶r̶o̶u̶g̶h̶ ̶f̶r̶i̶c̶t̶i̶o̶n̶ ̶a̶n̶d̶ ̶w̶a̶s̶t̶e̶ ̶h̶e̶a̶t̶ ̶f̶r̶o̶m̶ ̶t̶h̶e̶ ̶c̶i̶r̶c̶u̶l̶a̶t̶i̶o̶n̶ ̶p̶u̶m̶p̶s̶ ̶a̶n̶d̶ ̶d̶o̶n̶'̶t̶ ̶h̶a̶v̶e̶ ̶d̶e̶d̶i̶c̶a̶t̶e̶d̶ ̶w̶a̶t̶e̶r̶ ̶h̶e̶a̶t̶e̶r̶s̶.̶ ̶Y̶o̶u̶ ̶c̶o̶u̶l̶d̶ ̶a̶d̶d̶ ̶a̶ ̶s̶e̶p̶a̶r̶a̶t̶e̶,̶ ̶m̶o̶r̶e̶ ̶e̶f̶f̶i̶c̶i̶e̶n̶t̶,̶ ̶w̶a̶t̶e̶r̶ ̶h̶e̶a̶t̶e̶r̶ ̶a̶n̶d̶ ̶r̶u̶n̶ ̶t̶h̶e̶ ̶p̶u̶m̶p̶s̶ ̶l̶e̶s̶s̶ ̶o̶f̶t̶e̶n̶,̶ ̶b̶u̶t̶ ̶i̶t̶'̶s̶ ̶n̶o̶t̶ ̶a̶s̶ ̶s̶i̶m̶p̶l̶e̶ ̶a̶s̶ ̶r̶e̶p̶l̶a̶c̶i̶n̶g̶ ̶o̶n̶e̶ ̶k̶i̶n̶d̶ ̶o̶f̶ ̶h̶e̶a̶t̶e̶r̶ ̶w̶i̶t̶h̶ ̶a̶n̶o̶t̶h̶e̶r̶.̶ Never mind. Apparently I was misinformed. The circulation pump moves the water through the heater, but isn't the primary heat source.
- nkurz 5y ago
  I don't think this is true. Could you source this? I've had several small outdoor electric hot tubs, and all of them have had dedicated heaters. The couple times I've had problems with the heater, the symptoms involved the pump running constantly and the tub never reaching temp. I'm sure there is some friction heating, but I don't think it's anywhere near enough to reach standard temperature.
  - nybble41 5y ago
    Apparently you're correct, and I was misinformed. You could implement it this way—like how Tesla's newer designs can run the electric motor in a less-efficient mode to provide heat for the battery pack—but the designs I investigated did have separate heaters as part of the circulation system. (For some reason the specs for these were not listed in the product summary, but rather only in the manual.)
sbradford26 5y ago
So in NH I am paying just over $4.20 a gallon for propane and about $0.18 a kwh for electricity. With those prices a propane heater for my hot tub would cost more to run. Also a heat pump heater for the hot tub would optimistically get around a 3-4 COP in warmer weather and 2-3 in the colder weather but either of those would lower your price to heat it considerably but the capital expenses neglect those savings. Source: https://www.amsenergy.com/fuel-cost-calculator/ https://www.amsenergy.com/fuel-cost-calculator/
- wrycoder 5y ago
  Interesting, thanks. Looks like burning shelled corn is the way to go. Or coal.

throwaway48375 5y ago

That area is almost exclusively hydroelectric power.

wrycoder 5y ago
Er, which area is that? NH is almost entirely nuclear from the Seabrook site.
- throwaway48375 5y ago
  I just skimmed the article, but I thought it said it was in BC.