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Heat Pumps – The Well-Tempered Future of A/Cs

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141–150 of 406 posts

Re: Heat Pumps – The Well-Tempered Future of A/Cs

#141
post #137

Earlier quoted context omitted.

-40C? That's an extreme situation. Heat pumps can be installed with backup heating as I understand it.

> Heat pumps can be installed with backup heating as I understand it. Then, what's the point? If you still have to have gas lines and infra, just use the gas. It's vastly cheaper.

> Then, what's the point?

Minimizing your gas use?

Re: Heat Pumps – The Well-Tempered Future of A/Cs

#142

I live in a colder climate where heat pumps are not popular. After talking with a number of HVAC people about this I was surprised to learn that despite being very similar to an AC system in principle, in practice converting an AC system into a heat pump system doesn't make economic sense--you end up just ripping one out and installing the other. I don't fully understand why this is the case, but I hope that there's…

This persistent myth just needs to go away. People use heat pumps all over Scandinavia, including in the arctic circle. They are extremely popular there. They were early adopters of this technology there decades ago. There are two popular varieties: - Ground source heat pumps. Those work pretty much anywhere; just dig below the perma frost and you are good to go on the northern tip of Canada, Alaska, Norway, or where…

Ditto Australia.

We've been using 'reverse-cycle air-conditioners' for heating in Australia for decades. I'm puzzled as to why there is any debate at all on their use for heating. A heat-pump is far more efficient for obtaining heat than direct resistive heating using electricity.

Many houses here use no other form of heating at all. And then at the press of a button, we get cooling in summer too. What's not to like?

* I also have a heat-pump condensing clothes dryer. The overall heat thrown out into the room is extremely low. The hot-air comes out the hot-side of the heat-pump to dry the clothes. The warm-moist air then passes over the cold coils, condensing out the water from the clothes and returning the heat to the cold-side of the heat pump which then pushes that heat-energy out the hot-side, producing more hot air to complete the cycle. I've had this Miele heat-pump condensing dryer going strong since 2009 - 14 years.

Re: Heat Pumps – The Well-Tempered Future of A/Cs

#143
post #128
post #48

Earlier quoted context omitted.

Although natural gas is "clean" compared to, say, coal, the advantage of a heat pump is that it uses less total energy than natural gas. That means it would be more efficient to run a heat pump off a natural gas power plant than to burn natural gas to heat your home directly.

People's AC summertime electric bills regularly get into triple-digits - it's not uncommon to hear someone with a moderately sized home having a $200-400 electric bill in the summertime. However, even in the midst of winter, gas heating bills rarely climb above $100 monthly. What am I missing here? It seems a heatpump, while more efficient, will cost significantly more to operate. Natural Gas is cheap ... and clean e…

I'm with you here. I replaced a gas water heater with a hybrid water pump and I'm paying more for my troubles. The thing is, I do plan on installing PV panels in a few years--I can't generate my own gas so once I make that happen, I'll be a happy camper.

Re: Heat Pumps – The Well-Tempered Future of A/Cs

#144
post #81

Earlier quoted context omitted.

Walk around in the American Heating and Refrigeration conference for a while to get a feel of these trends, this was specifically called out by many manufacturers as driven by the green movement.

It's being driven by government pressure to reduce energy consumption and dependence on fuel imports. That isn't a bad thing. It's the sort of thing a responsible government should be planning for.

Being responsible is so trendy.

Re: Heat Pumps – The Well-Tempered Future of A/Cs

#145

My 20 year old air conditioner recently died and I was looking into replacements. In my climate the temperature ranges from 40C in the summer, and -40C in the winter. After doing some research, it seemed pretty clear that having a furnace+AC was the way to go for my climate. Hardly a magic bullet technology.

-40C? That's an extreme situation. Heat pumps can be installed with backup heating as I understand it.

> That's an extreme situation

Depends on where you live

Re: Heat Pumps – The Well-Tempered Future of A/Cs

#146
post #137

Earlier quoted context omitted.

> Heat pumps can be installed with backup heating as I understand it. Then, what's the point? If you still have to have gas lines and infra, just use the gas. It's vastly cheaper.

> Then, what's the point? If you still have to have gas lines and infra, just use the gas. It's vastly cheaper. A) Not everywhere B) Heat pumps can be powered with solar, reducing costs even if your gas would normally be cheaper C) Some people are willing to spend a little more if it helps push electrification forward, for environmental reasons

I tend to need heat when the sun isn't warming everything up.

Re: Heat Pumps – The Well-Tempered Future of A/Cs

#147

My 20 year old air conditioner recently died and I was looking into replacements. In my climate the temperature ranges from 40C in the summer, and -40C in the winter. After doing some research, it seemed pretty clear that having a furnace+AC was the way to go for my climate. Hardly a magic bullet technology.

Same situation, but I'm looking to replace the AC with a HP. For a little extra money, you get the flexibility to choose your heat source. Newer thermostats can be programmed to switch between the power sources and you can hedge against one price fluctuations in one of the power sources.

Re: Heat Pumps – The Well-Tempered Future of A/Cs

#148
post #20

I have both HVAC and a ducted heatpump for one part of the home. The biggest issue with the heatpump is that in the climate I live in there are times of year where you may have the heat on in the morning and the AC in the afternoon. Or you may leave and when you return you want to change the temperature. A furnace and an AC can do this rapidly. A heatpump takes time. It's more of a trickle of climatized air than a bl…

[deleted]

Re: Heat Pumps – The Well-Tempered Future of A/Cs

#149
post #137

Earlier quoted context omitted.

> Heat pumps can be installed with backup heating as I understand it. Then, what's the point? If you still have to have gas lines and infra, just use the gas. It's vastly cheaper.

> Then, what's the point? If you still have to have gas lines and infra, just use the gas. It's vastly cheaper. A) Not everywhere B) Heat pumps can be powered with solar, reducing costs even if your gas would normally be cheaper C) Some people are willing to spend a little more if it helps push electrification forward, for environmental reasons

> Some people are willing to spend a little more if it helps push electrification forward, for environmental reasons

It's not a little more though, that was the point. In my area, California, it's about 4x more. Gas here is so cheap, it's almost free.

Anecdotally, I don't know anyone who's opted into the "green energy" plans offered by the area's utility providers - because they all cost a lot more than regular.

People talk a lot - but their bank account dictates their actual decision making. Running a heatpump seems very expensive for a lot of the country, with negligible gains.

Natural Gas isn't exactly what we would call "dirty"... seems like a min-max issue, with people forgetting there's still areas burning coil and oil for electricity production.

> Heat pumps can be powered with solar

Not in the dead of winter you can't... not everyone lives in big cities folks, and where it snows, it gets quite cold.

Re: Heat Pumps – The Well-Tempered Future of A/Cs

#150

My 20 year old air conditioner recently died and I was looking into replacements. In my climate the temperature ranges from 40C in the summer, and -40C in the winter. After doing some research, it seemed pretty clear that having a furnace+AC was the way to go for my climate. Hardly a magic bullet technology.

Is that the typical range in a normal year? Or is that the all-time extreme record?

One thing people tend to do when they look at heat pumps is look at the typical extreme low for the year and size the heat pump based on that. But even if you touch -20 a few times a year, your heat pump doesn't need to be sized to heat in a constant -20. If you hit -20 once or twice per year then it's usually only for a few hours and the lowest that you really need to heat through is usually much closer to -10 or higher.

But, yes, if you're in a climate that sees frequent and sustained temps of -40 then a heat pump probably isn't for you or the rest of the Canadian Prairies.

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