71–80 of 83 posts
Earlier quoted context omitted.
Gas powered heat pumps also exist, using the same principle as gas powered refrigerators… from what I’ve heard they are already used in some countries but not on in the USA.
They are very likely denigrated as 'obsolete technology', but like all technology there are use-cases where a particular technology works best.
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As someone who switched four years ago to a heat pump plus conventional furnace, I can state from experience that my thermostat takes electricity cost per kWh and gas cost per therm (other units are available, these are just the ones that match my utility bills) and efficiency of both the heat pump and furnace and runs whichever is cheaper. Gas cost has varied a bunch over the years I’ve had it, electricity less so.…
> As someone who switched four years ago to a heat pump plus conventional furnace, I can state from experience that my thermostat takes electricity cost per kWh and gas cost per therm […] What is the make and model of the thermostat you are using? Is it from the heat pump OEM (Trane?) or a third party?
It’s a rebranded Nexia
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What fraction of the population lives with -40 degree winters? That's the only reason they might not be viable, in that they require customization that is only useful to a tiny tiny tiny fraction of the population.
A huge chunk of canadas population in Quebec, Ontario, prairies, and BC see -20 for weeks on end. -40 is more rare but happens every year. Huge chunks of the mid-western USA see those as well. At -30 my furnace is basically on continuously.
Why does these articles always leave out how electricity the pump needs and how that varys with temperature? It's not magic or free.
So far, 35% of households in my province have installed heat pumps, most keeping their EBBs or oil furnace as a backup. Every home that switches from EBBS is cutting their heating electricity usage by 50% (annually), freeing up electricity for the homes switching from oil furnaces to use for their heat pumps so our grid isn't being overloaded.
Earlier quoted context omitted.
What fraction of the population lives with -40 degree winters? That's the only reason they might not be viable, in that they require customization that is only useful to a tiny tiny tiny fraction of the population.
A huge chunk of canadas population in Quebec, Ontario, prairies, and BC see -20 for weeks on end. -40 is more rare but happens every year. Huge chunks of the mid-western USA see those as well. At -30 my furnace is basically on continuously.
In terms of cost, it's a lot cheaper than gas + electricity (it evens-out on the coolest days, and is cheaper otherwise). It will not amortize the cost of the heat pump itself for a while, but that's a cost I'm happy to eat right now.
As someone who switched to a heat pump recently, you should know "your mileage may vary." Don't confuse physical efficiency for cost efficiency. In many places, natural gas is still more cost efficient, even if it isn't as efficient in terms of physics.
As someone who switched four years ago to a heat pump plus conventional furnace, I can state from experience that my thermostat takes electricity cost per kWh and gas cost per therm (other units are available, these are just the ones that match my utility bills) and efficiency of both the heat pump and furnace and runs whichever is cheaper. Gas cost has varied a bunch over the years I’ve had it, electricity less so.…
Earlier quoted context omitted.
> As someone who switched four years ago to a heat pump plus conventional furnace, I can state from experience that my thermostat takes electricity cost per kWh and gas cost per therm […] What is the make and model of the thermostat you are using? Is it from the heat pump OEM (Trane?) or a third party?
Trane xl1050. It’s a rebranded Nexia
* https://www.bayareaservice.com/wp-content/uploads/2020/02/18...
Earlier quoted context omitted.
As someone who switched four years ago to a heat pump plus conventional furnace, I can state from experience that my thermostat takes electricity cost per kWh and gas cost per therm (other units are available, these are just the ones that match my utility bills) and efficiency of both the heat pump and furnace and runs whichever is cheaper. Gas cost has varied a bunch over the years I’ve had it, electricity less so.…
Can you give more detail about your system and in particular the thermostat that makes these adjustments? Sounds interesting!
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It's my experience that they do stop working completely at some temp. The defrost cycle creeps up to 100% and there goes the heat.
That's because the heat-exchanger is not efficient enough to prevent too much frost from building up. The answer there is a better (probably bigger) heat-exchanger.
I added an efficient wood stove instead. There's a good tax rebate that covers installation as well - I took advantage of that last year.
Earlier quoted context omitted.
They are very likely denigrated as 'obsolete technology', but like all technology there are use-cases where a particular technology works best.
Why they would be obsolete if more efficient than regular natural gas heat, which is by far the currently most widely used home heating technology?
When did you last see a kerosene-powered fridge? It's about 40 years since I last saw one. Hence my 'obsolete technology' label.
Reverse-cycle (heating) heat-pumps rely on fans to extract the heat away from the machine and send warm air into the room. If you have electricity for the fans, you might as well use that electricity to power the heat-pump too.