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Does anyone else find it interesting how overrepresented the topic of heat pumps are on hacker news lately?

voisin 3y ago
They operate at up to 400% efficiency and represent serious low hanging fruit for household carbon footprint reduction and the main barrier is education, so no I don’t think they are overrepresented.
- zabzonk 3y ago
  400% compared with what? and how?
  - AndrewDucker 3y ago
    They can shift 4x the amount of heat than the same amount of energy would generate.
  - jdlshore 3y ago
    A resistive electric heater converts 100% of its energy to heat, by essentially wasting it. A natural gas heater converts about 95% of its energy to heat, by burning it. A heat pump converts about 3x its energy to heat, by acting as a sort of reverse air conditioner that’s cold on the outside and warm on the inside.
  - thaumasiotes 3y ago
    400% is probably the ratio of thermal energy released by the heat pump to energy (of whatever kind) used to operate the pump.
    - baking 3y ago
      That has to depend on the outside temperature.
      - KMag 3y ago
        And also the indoor temperature. My recollection from designing these in class about 20 years ago is they typically operate at about half the Carnot efficiency.
- bitshiftfaced 3y ago
  I take your meaning, and it's a good point. But it's still interesting, even if you swap the framing for "underrepresented outside of hacker news."
- SlightlyLeftPad 3y ago
  Unfortunately, in California the electricity price is 6x the price of natural gas.
  - belthesar 3y ago
    This is a fair statement, but it represents an incomplete truth. Quick term run down, then some quick math. COP: Coefficient of Performance. This is a ratio of how much you can augment the temperature for every unit of energy you put in. Your best, most efficient top of the line gas furnace has a COP of 0.98. This means that, for every 1 joule of energy, you're getting 0.98 joules of heat energy. Let's say that, for easy math's sake, you pay $1 per joule for natural gas, so your operational cost for the furnace is $1.02 per joule. Yes, numbers are crazy town, but simple math for simple explanation. A modern bog-standard heat pump has a COP of 4. The operational COP of the heat pump varies depending on the difference in temperature from inside to outside, but the vast majority of the state of California is going to operate at temperatures that can support the COP. Per your statement, electricity is 6x the cost of gas, so we'll say that every joule of energy going into the heat pump costs $6. This puts your operational cost at $1.50 per joule. It's certainly not a "better deal", but the cost delta can't simply be measured by the cost of the energy going into the heating system.
    - sokoloff 3y ago
      > most efficient top of the line gas furnace has a COP of 0.98 That's a steady-state, best-case figure that is almost never achieved in practice. Very long run times and very low temperature operation is required to achieve those figures, and most homes are not setup to create those conditions. I'd not be surprised to learn that most 95+% efficient furnaces run at 90% realized.
      - voisin 3y ago
        This is super interesting. Do you have a source for this? I don’t doubt it, but I had never thought of it and it doesn’t surprise me that it is a misleading figure to begin with.
akamaka 3y ago
The entire world is going to switch away from using fossil fuels for home heating within the next 20 years, so you should expect to hear a lot about heat pumps going forward. In places like Europe, where gas prices have skyrocketed, the change is already happening with great urgency.
- smileysteve 3y ago
  And as global temperatures AND wealth related comforts are adopted; the cooling side is also increasing in use.
maineldc 3y ago
My theory is that heat pumps are before or right after the "chasm" in the technology adoption cycle and that's an exciting place to be! Skeptics can make good points about how over hyped they are, how the benefits are less than people think etc. Believers can feel excited about being an early adopter. It's the perfect circumstances for the people of hacker news.
- voisin 3y ago
  The other issue is that heat pumps were pretty awful in even remotely cold climates for decades, and there is some hangover due to bad experiences. But the technology has suddenly experienced a leap from being effective around -0C to -25C. It takes a while for industry to recognize that the technology has improved, and there are multiple generations that have done nothing but sling gas appliances and don’t want to upskill to know how to install heat pumps. I have had a hell of a time trying to get a trade anywhere near my small town that will actually install one. They all just use the introductory meeting to spread FUD about heat pumps. Same thing happened when I swapped from a gas water heater to a heat pump water heater. Lots of FUD, but I finally got the switch made and am so happy I recommend it to everyone. I also switched from a gas stove to induction and the FUD around induction was total bullshit and I’ve never been happier with an appliance. /endrant
  - foobarian 3y ago
    > suddenly experienced a leap from being effective around -0C to -25C. I was wondering what changed. Better refrigerants?
    - voisin 3y ago
      I believe so, yes.
  - distances 3y ago
    Maybe everyone should just point out that it's now the preferred heating method in all of the Nordics. If heat pumps work there reliably, it clearly is a proven technology. As a disclaimer, if you have an air source heat pump in a very cold environment you do need a backup heating method too, like direct electric or just a fireplace.
Finnucane 3y ago
It is literally the new hotness, and as the article says, getting clear info on it can be difficult. Our furnace--a gas tankless combi unit--probably has a few years of life left in it, but we want to plan for it's replacement, not wait until it fails in the middle of winter. Figuring out how well it will work in our location, with the pipes, radiators, etc, we have, seems to be not straightforward.
chucksta 3y ago
The northern hemisphere is going into the dead of winter, heating is on a lot of peoples mind
Angostura 3y ago
Given we are in a climate crisis and this one technically interesting solution ith a need for more innovation - the representation feels proportionate.

They operate at up to 400% efficiency and represent serious low hanging fruit for household carbon footprint reduction and the main barrier is education, so no I don’t think they are overrepresented.

zabzonk 3y ago
400% compared with what? and how?
- AndrewDucker 3y ago
  They can shift 4x the amount of heat than the same amount of energy would generate.
- jdlshore 3y ago
  A resistive electric heater converts 100% of its energy to heat, by essentially wasting it. A natural gas heater converts about 95% of its energy to heat, by burning it. A heat pump converts about 3x its energy to heat, by acting as a sort of reverse air conditioner that’s cold on the outside and warm on the inside.
- thaumasiotes 3y ago
  400% is probably the ratio of thermal energy released by the heat pump to energy (of whatever kind) used to operate the pump.
  - baking 3y ago
    That has to depend on the outside temperature.
    - KMag 3y ago
      And also the indoor temperature. My recollection from designing these in class about 20 years ago is they typically operate at about half the Carnot efficiency.
bitshiftfaced 3y ago
I take your meaning, and it's a good point. But it's still interesting, even if you swap the framing for "underrepresented outside of hacker news."
SlightlyLeftPad 3y ago
Unfortunately, in California the electricity price is 6x the price of natural gas.
- belthesar 3y ago
  This is a fair statement, but it represents an incomplete truth. Quick term run down, then some quick math. COP: Coefficient of Performance. This is a ratio of how much you can augment the temperature for every unit of energy you put in. Your best, most efficient top of the line gas furnace has a COP of 0.98. This means that, for every 1 joule of energy, you're getting 0.98 joules of heat energy. Let's say that, for easy math's sake, you pay $1 per joule for natural gas, so your operational cost for the furnace is $1.02 per joule. Yes, numbers are crazy town, but simple math for simple explanation. A modern bog-standard heat pump has a COP of 4. The operational COP of the heat pump varies depending on the difference in temperature from inside to outside, but the vast majority of the state of California is going to operate at temperatures that can support the COP. Per your statement, electricity is 6x the cost of gas, so we'll say that every joule of energy going into the heat pump costs $6. This puts your operational cost at $1.50 per joule. It's certainly not a "better deal", but the cost delta can't simply be measured by the cost of the energy going into the heating system.
  - sokoloff 3y ago
    > most efficient top of the line gas furnace has a COP of 0.98 That's a steady-state, best-case figure that is almost never achieved in practice. Very long run times and very low temperature operation is required to achieve those figures, and most homes are not setup to create those conditions. I'd not be surprised to learn that most 95+% efficient furnaces run at 90% realized.
    - voisin 3y ago
      This is super interesting. Do you have a source for this? I don’t doubt it, but I had never thought of it and it doesn’t surprise me that it is a misleading figure to begin with.

akamaka 3y ago

The entire world is going to switch away from using fossil fuels for home heating within the next 20 years, so you should expect to hear a lot about heat pumps going forward. In places like Europe, where gas prices have skyrocketed, the change is already happening with great urgency.

smileysteve 3y ago
And as global temperatures AND wealth related comforts are adopted; the cooling side is also increasing in use.

maineldc 3y ago

My theory is that heat pumps are before or right after the "chasm" in the technology adoption cycle and that's an exciting place to be! Skeptics can make good points about how over hyped they are, how the benefits are less than people think etc. Believers can feel excited about being an early adopter. It's the perfect circumstances for the people of hacker news.

voisin 3y ago
The other issue is that heat pumps were pretty awful in even remotely cold climates for decades, and there is some hangover due to bad experiences. But the technology has suddenly experienced a leap from being effective around -0C to -25C. It takes a while for industry to recognize that the technology has improved, and there are multiple generations that have done nothing but sling gas appliances and don’t want to upskill to know how to install heat pumps. I have had a hell of a time trying to get a trade anywhere near my small town that will actually install one. They all just use the introductory meeting to spread FUD about heat pumps. Same thing happened when I swapped from a gas water heater to a heat pump water heater. Lots of FUD, but I finally got the switch made and am so happy I recommend it to everyone. I also switched from a gas stove to induction and the FUD around induction was total bullshit and I’ve never been happier with an appliance. /endrant
- foobarian 3y ago
  > suddenly experienced a leap from being effective around -0C to -25C. I was wondering what changed. Better refrigerants?
  - voisin 3y ago
    I believe so, yes.
- distances 3y ago
  Maybe everyone should just point out that it's now the preferred heating method in all of the Nordics. If heat pumps work there reliably, it clearly is a proven technology. As a disclaimer, if you have an air source heat pump in a very cold environment you do need a backup heating method too, like direct electric or just a fireplace.

Finnucane 3y ago

It is literally the new hotness, and as the article says, getting clear info on it can be difficult. Our furnace--a gas tankless combi unit--probably has a few years of life left in it, but we want to plan for it's replacement, not wait until it fails in the middle of winter. Figuring out how well it will work in our location, with the pipes, radiators, etc, we have, seems to be not straightforward.

chucksta 3y ago

The northern hemisphere is going into the dead of winter, heating is on a lot of peoples mind

Angostura 3y ago

Given we are in a climate crisis and this one technically interesting solution ith a need for more innovation - the representation feels proportionate.