5 ms·

People are going to be very disappointed by their heating bills. Electric heating is expensive as hell, and gas is usually included in rent. My small studio a

People are going to be very disappointed by their heating bills. Electric heating is expensive as hell, and gas is usually included in rent. My small studio a few years back was +200$ in winter months with crummy electric heat.

Danieru 5y ago
> Electric heating is expensive Air heat pumps are cheaper to heat with than gas in most situations. It takes rather extreme cold and cheap gas to out compete the 400%+ efficiency of heat pumps. Technology is pretty awesome.
- hattmall 5y ago
  How do they get the efficiency number above 100? Are heat pumps that efficient at cooling as well?
  - gregable 5y ago
    It depends on your definition of efficiency. Electric heat is considered 100% efficient as 100% of the watt hours that go into the device eventually get turned into the same amount of heat. A heat pump moves heat from outdoors to indoors. The outdoor heat lost is ignored in the efficiency calculation (as it should be), and thus the efficiency question is how many watt hours of electricity does it take to move a watt hour of heat (joules) from outside to inside. Depending on the temperatures involved, it's usually a multiple, for example, 1 wH of electricity moves 4 wH equivalent of heat indoors, ie: 400% efficient. If you consider the whole system, much of the electricity for a heat pump may come from burning natural gas elsewhere, which involves losses along the way. This is still usually better than 100% overall efficiency. Direct natural gas heating is less than 100% efficient too. Most furnace systems are about 20% loss in exhaust, though they can be much better. This is still usually better than burning the gas at a plant, converting to electricity and then heating with resistive electrical in your home.
    - syshum 5y ago
      Most modern gas furnaces are 95% AFUE, the minimum in northern US states is 90% And comparing AFUE efficiency to HSPF is not really a thing, you can not look at a gas furance that is 95% AFUE, and a Heat Pump that is "400%" claim that the gas furnace is must less "efficient" that is not how any of those works. To be clear a heat pump at temps above 25 degrees Fahrenheit is more efficient but comparing the metrics in this manner is a bit misleading Further heat pumps are good to 25 to 30 degrees Fahrenheit, under that a gas furnace is normally used to supplement a heat pump in colder climates. Most heat pump manufacturers do not recommend operating a heat pump in below freezing conditions
      - dieortin 5y ago
        Then how would you say it should be compared?
      - rudedogg 5y ago
        > Further heat pumps are good to 25 to 30 degrees Fahrenheit, under that a gas furnace is normally used to supplement a heat pump in colder climates. Most heat pump manufacturers do not recommend operating a heat pump in below freezing conditions Just wanted to chime in that they do make a lot of low-temp heat pumps, going down to -30f now. The efficiency drops dramatically at temps that low, the best site to look at cold-weather models is https://ashp.neep.org/#!/product_list/ https://ashp.neep.org/#!/product_list/ If you look though, the "COP @ 5 degrees F" for a lot of models is above 2.0, which from my understanding means you'll be using 1/2 the electricity someone with baseboard (resistance) heat would. And above those temps the COP gets much higher.
  - dghlsakjg 5y ago
    Heat pumps are actually exactly what the title says. Using compressors they are able to extract heat even from relatively cold air and transfer the energy inside. They can use 100 watts of electric energy to move 400 watts of heat from outside to inside. The downside is that the colder it is outside the less efficient they get (since there is less heat outside) so it only works in relatively temperate climates.
    - hattmall 5y ago
      What I don't get is the comparison to gas though. Like how can burning natural gas to generate electricity then using that electricity on a separate device be more efficent than just burning the natural gas directly for heat. The essential output of natural gas is heat to generate electricity if the heat pump were 4x efficient then could a natural gas plant generate electricity, run a giant heat pump and then use the heat to generate 4x more electricity?
    - XorNot 5y ago
      This does only apply for air-sourced heat pumps though. Unless you are literally living on an ice-sheet, a ground-sourced heat pump can be efficient all-year round and beat out an air system easily.
      - dghlsakjg 5y ago
        Fascinating. I’m in the PNW where I don’t think it gets cold enough for this to matter
- endisneigh 5y ago
  Though I agree that heat pumps are more efficient and cheaper (ongoing) - they're still more expensive to install. I'd say the #1 plus is that you get air conditioning or free, and so in that way it's simpler.
  - bpicolo 5y ago
    That is probably an issue - suspect developers ultimately are going to pick the cheap-for-them version. (Probably what happened in my case)
  - BostonEnginerd 5y ago
    I doubt that they’re cheaper to install if you’re already putting in air conditioning. Plus you save the $30/mo meter fee from the gas company.
- syshum 5y ago
  NYC has "extreme cold" and likely puts heat pumps into their very inefficient range many days of the year.
  - kbajorin 5y ago
    It's generally fairly temperate in NYC. The Daikin in my building runs at 100% capacity down to -4F. The last time NYC recorded below -4 was 1943.
- JshWright 5y ago
  They aren't generally cheaper "enough" to operate to justify the increased equipment cost over gas. A lot of that has to do with natural gas subsidies in New York though, which I expect to change in the near future.
- tag2103 5y ago
  I hate to bring practical experience with a heat pump to the table but ours is a 3 year old unit and last February in the Texas "blizzard" the heat pump became a solid block of ice and the system ended up using backup "glow rods" to heat the air. Glow rods are about as efficient as an old coil burner type range- exact same principle. Heat pumps aren't a panacea, they have an appropriate use. Usually in a warm climate but they don't really work well (from my direct experience) in freezing temperatures or below. Something I assume NYC gets rather regularly.
  - Danieru 5y ago
    You're the victim of cost optimization. A old climate optimized heat pump will have logic to run the pump in reverse to melt the accumulated ice. This happens without you noticing but it let's the pump keep going and keeps the net efficiency above a coefficient of 1. If anything America is a victem of HVAC "specialists" who use their skills to install the bare minimum systems. Over in Japan everyone just buys a featurefull mini split and pokes a hole in the way and plugs it in. The net effect is Japan has a competitive market for featureful yet cheap minisplits. While Americians are forced to pay more for less.
- indymike 5y ago
  > Technology is pretty awesome. So I have a heat pump. In central Indiana. Temp ranges from -15F in the winter to 100F in the summer. Today it was in the mid 50s. My across the street neighbor has the same floorplan house, but he has gas. When we compare bills, I pay about $40/mo more for heat. He pays about $40 more for AC... so it ends up being a wash, except my HVAC plant cost about twice what his conventional electric AC / Gas forced air setup. As a bonus, the electric that I use comes from a giant gas plant so... Would feel better about electric if it wasn't just shifting production to a giant facility on the other side of town.
  - karmanyaahm 5y ago
    > As a bonus, the electric that I use comes from a giant gas plant so Yes, however, that won't be the case for long (hopefully).
    - indymike 5y ago
      > Yes, however, that won't be the case for long (hopefully). Ok, so, what are we going to generate energy with? Nuclear is a non-starter, coal is dirty, so without gas, wind and solar are simply not capable of getting the job done in a cold snap.
kibwen 5y ago
This seems to be for new buildings, not existing buildings. And for new buildings, one would hope that they would forego electric resistive heating in favor of reversible electric heat pumps for dual cooling/heating, which are competitive or better in cost versus natural gas (depending on various local factors).
natch 5y ago
If you think electric heating is expensive, wait until you see how much it will cost to keep ocean water out.
scatters 5y ago
Was that resistive, or heat pump?
dzhiurgis 5y ago
My builder estimates 30w/square meter in norther europe - but the house is built to an A+ insulation level
Gigachad 5y ago
There are basically two options I see. One is implementing a general greenhouse gas tax and charge the shit out of people who use gas heating until they upgrade to more efficient systems. And the other is to mandate new builds comply with efficiency ratings. The first option has the benefit of being generalised and applying to everything. But it hurts in the short term. The second option has the benefit of being a painless transition for everyone but could result in sub optional choices being made by the government.

Danieru 5y ago

> Electric heating is expensive Air heat pumps are cheaper to heat with than gas in most situations. It takes rather extreme cold and cheap gas to out compete the 400%+ efficiency of heat pumps. Technology is pretty awesome.

hattmall 5y ago
How do they get the efficiency number above 100? Are heat pumps that efficient at cooling as well?
- gregable 5y ago
  It depends on your definition of efficiency. Electric heat is considered 100% efficient as 100% of the watt hours that go into the device eventually get turned into the same amount of heat. A heat pump moves heat from outdoors to indoors. The outdoor heat lost is ignored in the efficiency calculation (as it should be), and thus the efficiency question is how many watt hours of electricity does it take to move a watt hour of heat (joules) from outside to inside. Depending on the temperatures involved, it's usually a multiple, for example, 1 wH of electricity moves 4 wH equivalent of heat indoors, ie: 400% efficient. If you consider the whole system, much of the electricity for a heat pump may come from burning natural gas elsewhere, which involves losses along the way. This is still usually better than 100% overall efficiency. Direct natural gas heating is less than 100% efficient too. Most furnace systems are about 20% loss in exhaust, though they can be much better. This is still usually better than burning the gas at a plant, converting to electricity and then heating with resistive electrical in your home.
  - syshum 5y ago
    Most modern gas furnaces are 95% AFUE, the minimum in northern US states is 90% And comparing AFUE efficiency to HSPF is not really a thing, you can not look at a gas furance that is 95% AFUE, and a Heat Pump that is "400%" claim that the gas furnace is must less "efficient" that is not how any of those works. To be clear a heat pump at temps above 25 degrees Fahrenheit is more efficient but comparing the metrics in this manner is a bit misleading Further heat pumps are good to 25 to 30 degrees Fahrenheit, under that a gas furnace is normally used to supplement a heat pump in colder climates. Most heat pump manufacturers do not recommend operating a heat pump in below freezing conditions
    - dieortin 5y ago
      Then how would you say it should be compared?
    - rudedogg 5y ago
      > Further heat pumps are good to 25 to 30 degrees Fahrenheit, under that a gas furnace is normally used to supplement a heat pump in colder climates. Most heat pump manufacturers do not recommend operating a heat pump in below freezing conditions Just wanted to chime in that they do make a lot of low-temp heat pumps, going down to -30f now. The efficiency drops dramatically at temps that low, the best site to look at cold-weather models is https://ashp.neep.org/#!/product_list/ https://ashp.neep.org/#!/product_list/ If you look though, the "COP @ 5 degrees F" for a lot of models is above 2.0, which from my understanding means you'll be using 1/2 the electricity someone with baseboard (resistance) heat would. And above those temps the COP gets much higher.
- dghlsakjg 5y ago
  Heat pumps are actually exactly what the title says. Using compressors they are able to extract heat even from relatively cold air and transfer the energy inside. They can use 100 watts of electric energy to move 400 watts of heat from outside to inside. The downside is that the colder it is outside the less efficient they get (since there is less heat outside) so it only works in relatively temperate climates.
  - hattmall 5y ago
    What I don't get is the comparison to gas though. Like how can burning natural gas to generate electricity then using that electricity on a separate device be more efficent than just burning the natural gas directly for heat. The essential output of natural gas is heat to generate electricity if the heat pump were 4x efficient then could a natural gas plant generate electricity, run a giant heat pump and then use the heat to generate 4x more electricity?
  - XorNot 5y ago
    This does only apply for air-sourced heat pumps though. Unless you are literally living on an ice-sheet, a ground-sourced heat pump can be efficient all-year round and beat out an air system easily.
    - dghlsakjg 5y ago
      Fascinating. I’m in the PNW where I don’t think it gets cold enough for this to matter
endisneigh 5y ago
Though I agree that heat pumps are more efficient and cheaper (ongoing) - they're still more expensive to install. I'd say the #1 plus is that you get air conditioning or free, and so in that way it's simpler.
- bpicolo 5y ago
  That is probably an issue - suspect developers ultimately are going to pick the cheap-for-them version. (Probably what happened in my case)
- BostonEnginerd 5y ago
  I doubt that they’re cheaper to install if you’re already putting in air conditioning. Plus you save the $30/mo meter fee from the gas company.
syshum 5y ago
NYC has "extreme cold" and likely puts heat pumps into their very inefficient range many days of the year.
- kbajorin 5y ago
  It's generally fairly temperate in NYC. The Daikin in my building runs at 100% capacity down to -4F. The last time NYC recorded below -4 was 1943.
JshWright 5y ago
They aren't generally cheaper "enough" to operate to justify the increased equipment cost over gas. A lot of that has to do with natural gas subsidies in New York though, which I expect to change in the near future.
tag2103 5y ago
I hate to bring practical experience with a heat pump to the table but ours is a 3 year old unit and last February in the Texas "blizzard" the heat pump became a solid block of ice and the system ended up using backup "glow rods" to heat the air. Glow rods are about as efficient as an old coil burner type range- exact same principle. Heat pumps aren't a panacea, they have an appropriate use. Usually in a warm climate but they don't really work well (from my direct experience) in freezing temperatures or below. Something I assume NYC gets rather regularly.
- Danieru 5y ago
  You're the victim of cost optimization. A old climate optimized heat pump will have logic to run the pump in reverse to melt the accumulated ice. This happens without you noticing but it let's the pump keep going and keeps the net efficiency above a coefficient of 1. If anything America is a victem of HVAC "specialists" who use their skills to install the bare minimum systems. Over in Japan everyone just buys a featurefull mini split and pokes a hole in the way and plugs it in. The net effect is Japan has a competitive market for featureful yet cheap minisplits. While Americians are forced to pay more for less.
indymike 5y ago
> Technology is pretty awesome. So I have a heat pump. In central Indiana. Temp ranges from -15F in the winter to 100F in the summer. Today it was in the mid 50s. My across the street neighbor has the same floorplan house, but he has gas. When we compare bills, I pay about $40/mo more for heat. He pays about $40 more for AC... so it ends up being a wash, except my HVAC plant cost about twice what his conventional electric AC / Gas forced air setup. As a bonus, the electric that I use comes from a giant gas plant so... Would feel better about electric if it wasn't just shifting production to a giant facility on the other side of town.
- karmanyaahm 5y ago
  > As a bonus, the electric that I use comes from a giant gas plant so Yes, however, that won't be the case for long (hopefully).
  - indymike 5y ago
    > Yes, however, that won't be the case for long (hopefully). Ok, so, what are we going to generate energy with? Nuclear is a non-starter, coal is dirty, so without gas, wind and solar are simply not capable of getting the job done in a cold snap.

kibwen 5y ago

This seems to be for new buildings, not existing buildings. And for new buildings, one would hope that they would forego electric resistive heating in favor of reversible electric heat pumps for dual cooling/heating, which are competitive or better in cost versus natural gas (depending on various local factors).

natch 5y ago

If you think electric heating is expensive, wait until you see how much it will cost to keep ocean water out.

scatters 5y ago

Was that resistive, or heat pump?

dzhiurgis 5y ago

My builder estimates 30w/square meter in norther europe - but the house is built to an A+ insulation level

Gigachad 5y ago

There are basically two options I see. One is implementing a general greenhouse gas tax and charge the shit out of people who use gas heating until they upgrade to more efficient systems. And the other is to mandate new builds comply with efficiency ratings. The first option has the benefit of being generalised and applying to everything. But it hurts in the short term. The second option has the benefit of being a painless transition for everyone but could result in sub optional choices being made by the government.