Heat Pump Sales Outpaced Gas Furnace Sales In the US In 2022 (electrek.co) 142
In the US, heat pump purchases exceeded those of gas furnaces in 2022 -- part of a bigger trend that saw global heat pump sales grow by 11%. Electrek reports: According to analysis released today by the International Energy Agency (IEA), heat pump sales in Europe saw a record year, with sales growing by nearly 40%. And specifically, sales of air-to-water models in Europe that are compatible with typical radiators and underfloor heating systems jumped by almost 50%. In China, the world's largest heat pump market, sales remained stable amid a general slowdown of the economy.
Currently, heat pumps function as a main heating device in around 10% of buildings globally. That's the equivalent of over 100 million households, or 1 in 10 homes. But in order to meet climate goals, heat pumps will have to meet nearly 20% of global heating needs in buildings by 2030. If installations continue at the rate of the last two years, then the world may almost be on track to reach the 2030 goal. The IEA says that global heat pump sales will need to expand by well over 15% per year this decade if the world is to achieve net zero by 2050, and that multistory apartment buildings and commercial spaces in particular should be prioritized.
Currently, heat pumps function as a main heating device in around 10% of buildings globally. That's the equivalent of over 100 million households, or 1 in 10 homes. But in order to meet climate goals, heat pumps will have to meet nearly 20% of global heating needs in buildings by 2030. If installations continue at the rate of the last two years, then the world may almost be on track to reach the 2030 goal. The IEA says that global heat pump sales will need to expand by well over 15% per year this decade if the world is to achieve net zero by 2050, and that multistory apartment buildings and commercial spaces in particular should be prioritized.
Some downsides, though (Score:2, Informative)
Heat pumps typically don't last as long as a gas or oil furnace. An air-source heat pump system defrosts by periodically switching back into air conditioning mode while the system is running. This results in the majority of the system's refrigerant charge being dumped directly into the suction accumulator every time the flow is reversed, which puts extra strain on the compressor until all the refrigerant re-evaporates. This defrost cycle is also one of the reasons a common FAQ for heat pumps is "is it no
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If you live in someplace cold enough that icing is a problem, then you need a ground source heat pump, which won't do that.
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If you live in someplace cold enough that icing is a problem, then you need a ground source heat pump, which won't do that.
It's not the temperature which causes the outdoor unit to ice over (the outdoor coil, which acts a condenser while in heat pump mode, is going to be operating well below freezing as part of normal operation), it's the humidity. Counterintuitively, air-source heat pumps tend to be more prone to icing in climates where they make the most economic sense to use in the first place: in the southeastern states where humidity does tend to be higher year-round.
Ground source heat pumps are significantly more costly
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Why is everyone posting about air heat pumps. Underground it's a consistent temperature year round with a huge heatsink to draw from.
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Why is everyone posting about air heat pumps. Underground it's a consistent temperature year round with a huge heatsink to draw from.
Maybe if you're building a new house where digging up things is fairly straightforward, but for an existing house you typically go with what's there, which means an air source heat pump.
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Because if you have an air conditioner, or considering getting air conditioning, you're about 95% of the way to making it a "full heat pump" (ignoring the fact that an air conditioner is a heat pump already - heat pump in this context refers to a bi-directional heat pump). After all, the major difference from your regular air conditioning unit and a heat pump is a reversing va
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Let's say you live alone and use a smart thermostat to keep your residence at slightly above freezing while you're out. A properly sized gas/oil furnace will quickly warm up your home when you return. Heat pumps, on the other hand are generally sized for the expected summer cooling load and if an energy-saving thermostat allows the living space to become too cold, the system may never catch up.
That sounds incredibly suspicious to me, because that's not the way heat works. Heat flow is proportional to the te
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The increased Delta T across an insulator is what causes the energy loss. As the difference between the temperature inside and outside your home increases, a proportionally greater transfer of heat energy to the cooler side takes place. That's entirely why energy saving thermostats work in the first place.
In a nutshell, leaving the house cold during the day means you lose less heat to the outside. As to being able to warm things back up quickly, that's just a function of BTUs available from your heating
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Mitsubishi's technology is about enabling the unit to produce its rated capacity at lower outdoor ambient temperatures than traditional heat pumps. What I was referring to in my original post was how equipment is typically sized.
A 5-ton (60,000BTU/h) air conditioner/heat pump is the largest size system you'll typically see in residential use. If a house needs more cooling/heating than that, additional systems are installed. Yeah, it's actually somewhat funny to see rows of outdoor units on the side of ve
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> Ever wonder how those Mitsubishi "Hyper Heat" mini-splits work?
I did, so I asked the engineering rep I often work with since I spec a lot of Mitsubishi equipment.
It works by recycling the waste heat of the compressor motor in combination with enhanced vapor injection strategy where a portion of the refrigerant is used, via heat exchanger, to sub-cool the bulk of the refrigerant headed for the evaporator. The sub-cooled refrigerant can them absorb more energy in colder temperatures, and the excess heat
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That sounds incredibly suspicious to me, because that's not the way heat works.
It's the way heat pumps work. They absolutely *SUCK* for setback thermostats. Most programmable thermostats don't even work on heat pumps. They tell you on the package. You will be lucky to find one in Lowes that does and if you do it will be three times the cost of others.
When you set back and the temperature program returns to heat, the temperature difference is greater than the difference for the aux heat trigger. If you have electric resistance emergency heat, there is no cost savings and general
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You should also insulate your home. That alone will save you a huge amount of money, and mean that the heat pump has a lot less work to do. It seems that many American homes are poorly insulated, and use the historically low cost of gas (relative to other countries) to make up for it.
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You should also insulate your home. That alone will save you a huge amount of money, and mean that the heat pump has a lot less work to do. It seems that many American homes are poorly insulated
And yet, they are still typically drastically better-insulated than homes in the UK. Europe is not one place, it's a region. Also, it really depends on where the homes are. In the US north or midwest, the insulation is usually very good, because it's very important. Also, historically we've been able to get a cord of hardwood for under $300, so the insulation hasn't been so critical here. It's only now that trees are in short supply and weather is more unpredictable that we're having big heating problems.
Get ready ... (Score:2)
Heat Pumps not as good as Natural Gas (Score:2)
Had one put 10 years ago in upstairs unit because of tax subsidy.
Downstairs unit much warmer with gas,
Now Electricity prices have almost Doubled in the past 2 years.
Natural gas is Much cheaper, at least for heating.
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When it's super cold outside their efficiency of the heatmap approaches zero and you end up on emergency heat.
That is true for air-source heat pumps, but not for ground-source heat pumps.
If you live where winters are cold, ground-source is the way to go.
Even in milder climates, a ground-source heat pump is more efficient but is more expensive to install.
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"That is true for air-source heat pumps, but not for ground-source heat pumps."
The ground around here freezes in the winter, so I don't know how well that would work.
(46 degrees North latitude)
Re:My opinion of them (Score:5, Interesting)
BLUF: You bury the ground loop deeper the closer to the poles you are.
Okay, 65 degrees North latitude here. Ground doesn't just freeze in the winter, we have permafrost in areas. As in the ground doesn't even defrost in the summer. You can STILL make ground source heat pumps work this far north, it's just that the depth of the ground loop goes up.
46 degrees north latitude isn't bad at all.
Around 40 is probably "ideal", in that you're putting around as much heat into the ground via cooling your house, as you're extracting for heating it.
One of the ideas I examined in college was actually installing solar heating sufficient to cover 100% of my house. In Fairbanks, AK.
You might go "huh, wah?" - But here's the trick: The system I proposed was a massive heat sink/ transfer system. Basically, build a massive insulated box under the house. Think of a 12 foot sub-basement. Fill it back up with the dirt/sand, putting piping(probably pex) in as you go), top off with water for the extra mass and heat transfer rate.
How you exactly do it is optional, but after that you hook up solar thermal panels covering ~50% of your roof. This helps keep your house cooler in the summer, but more importantly, you're storing that heat in your insulated box. You then heat your house using a ground source heat pump that is pulling heat from the box. Well, that and if you install the necessary flow logic, you can heat the house using the flow from the solar panels directly if there's sufficient heat there. If the box is hot enough, you don't need the heat pump version, but a heat pump version allows the box to get much colder while staying useful. It reduces waste heat loss a lot if the box isn't as hot, so you don't need as much solar.
Totally impractical for a retrofit, not completely electricity free, but actually didn't have a bad payoff time because the digging and piping wasn't incredibly expensive, and when heating, even with oil, is that expensive... Probably work better with a more modern super-insulated(not that my house wasn't heavily insulated) house to reduce the needed size of everything. Probably want a "mass intensive" house - A house with a lot of concrete/stone/brick in the walls, with the insulation on the OUTSIDE of the walls, in order to provide a lot of thermal inertia.
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Mmm... slashdot users afraid of technology. Incels.
Re: My opinion of them (Score:2)
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Not that much cheaper, actually. Because you have to go so DEEP under the permafrost that it gets quite expensive.
One problem with heat pumps that far north may not manifest for a few years, but because the heating demand is so much higher than the cooling, you have to oversize the bore system so you don't end up freezing the ground around your heat loop.
That problem is why I came up with dumping solar heat into it over time.
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Basically, build a massive insulated box under the house. Think of a 12 foot sub-basement. Fill it back up with the dirt/sand, putting piping(probably pex) in as you go), top off with water for the extra mass and heat transfer rate.
Your idea is similar to the "sand battery" implemented in Finland, as mentioned here: https://www.bbc.com/news/scien... [bbc.com] and discussed here: https://science.slashdot.org/s... [slashdot.org] Except in Finland they heat the sand to much higher temperatures (500C), using resistive heating from PV or wind turbines, instead of thermal solar.
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PV was still a lot more expensive back when I did my little feasibility study/report.
It also predated this report by about a decade.
So use cheaper solar thermal panels, heating the soil to a lower temperature. 500C, oof.
The higher temperatures would mean that direct thermal heating is easily possible, but is more expensive on the front end (PV vs Thermal, but they're close to the same price today), in order to save on the back end.
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And how does one get the loop into the rock of the mountain side?
How do they get deep oil/gas wells? They have drills for that.
Or you go for my box, which doesn't need that much depth. Dynamite works well for that.
Note that I wasn't addressing "one size fits all", and that I noted that my "solution" ended up being impractical. Not a good payoff time, but it was a project in college, I got credit for doing the workup. I think it even made its way into potential applications elsewhere.
Gas/Oil is going up
Re:My opinion of them (Score:4, Funny)
Dynamite works well for that.
Probably not a great choice for retrofits though. :)
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Why not? It just means you're retrofitting the whole house. ;)
Re: My opinion of them (Score:2)
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Its really too bad nobody has figured out how to drill or fracture rocks yet. One of these days someone will discover the breakthrough to make that possible!
Re: My opinion of them (Score:2)
A lot of places don't allow open loops to protect the drinking water.
That's why most systems are closed loop systems. Think a normal well borehole, but you put two pipes connected at that bottom, and then fill grout in to fill the area between the pipes and the wall.
That way the heat transfer fluid never leaves the system. It exchanges heat with the ground as it goes down. Once you get like 10 to 50 feet deep, the ground temperature is like 40 to 60 degrees year round, even in Antarctica.
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It seems unproductive to complain about people not choosing the more expensive option that produce no long-term savings. This is causing great resistant to change if when the change is good. This is one of the grea
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Re: My opinion of them (Score:5, Informative)
There have been a lot of improvements in the last few years. Older heat pumps were pretty much worthless below about 20*F. Newer ones work well down to about -10*F. If itâ(TM)s regularly colder than that where you live, having gas backup makes sense.
Re: My opinion of them (Score:3, Informative)
Re: My opinion of them (Score:3)
For those of us in hot climates (myself included), my biggest gripe is that heat pumps are slight less efficient in cool mode. For example, the Carrier infinity A/c unit will go up to 26SEER, but its heat pump equivalent is only rated at 24SEER. Thatâ(TM)s almost a 10% efficiency hit from having the heat capability. That makes a difference for those of us who can see $500 cooling bills in peak summer.
Re: My opinion of them (Score:5, Interesting)
When I shopped AC last year the super high end 24+ SEER stuff was so expensive compared to 16, the ROI was a longer time frame than the expected life of the unit.
Ymmv but I replaced some really old shit with 16's and saw a dramatic drop in my electric bill. 26 wouldn't be so much lower as to be worth it. There just isn't that much room left in my electric bill to recover from a higher SEER unit. I live in a very hot place so ac is on all day, too.
Everyone should do their own long term roi math before buying anything. Everyone's situation is unique.
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Also, single zone central heating/cooling is a waste of electricity no matter how high the SEER rating. Better to go with multi-zone, perhaps one zone for the bedrooms where people will sleep and another zone for the other rooms that don't need as much heat overnight.
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True but I'm the third or fourth owner so had no input into house design.
In my case they made the master suite a zone and the rest of the house a second larger zone. It works well enough since we're mostly in the house part and only use the master unit at night.
Re: My opinion of them (Score:2)
YMMV on the high vs low SEER stuff. I was able to buy a 26 SEER unit online and found a company willing to install it. Final price was what I was quoted for 16 SEER from another HVAC company.
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Yeah my all in quotes varied a lot too. Was about 60% difference for very similar units from high quote to bottom quote. I took the second bottom because they seemed to know better what they were talking about and weren't a whole lot higher than bottom.
I popped a small leak 3 days ago. They sent a guy out 45m later to fix it under warranty and he encouraged me to ask any and all questions I could think of before he left. Totally worth paying a little extra for the system last year.
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It's very likely that it would be much better to improve your home insulation than to buy a more efficient air conditioner. Just prevent the heat from coming inside in the first place. Even basic stuff like adding shutters to the windows (on the outside) and fixing major leaks can make huge difference. Some people have hooks outside their windows that they can hang blinds on in the summer, that simple and cheap.
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Insulation check is on my list.
I _had_ to replace the AC though. They were about 14 years old, leaking a lot of water, super loud, super inefficient, and didn't cool very well anyway.
It sucked and cost a lot but new units cool great, are super quiet, and my bill instantly dropped a few hundred bucks a month. Since replacement was required I see the improvements and lower cost as almost like a side benefit.
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Absolutely. Haven't been in the house too long so i've been spending time/money on things that were super messed up like the ac, the pool pump not pumping, adding solar, the various leaks, holes, rats above the garage and so on. Ugh. Down to my last few smaller projects then I can see if it can use more insulation, maybe swap the old water tank (it's way past expected life span) for tankless electric, get some bug screens up and other quality of life stuff.
Ah, the joys of home ownership!
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maybe swap the old water tank (it's way past expected life span) for tankless electric
Trust me on this, you do not want one of those.
The original tank water heater in my home was in the master bedroom closet. It was a massive pain in the ass to remove and clean up the resulting mess when it sprung a leak. I figured it would be a great idea to install something that would be easier to deal with as the replacement, so I ran some crazy heavy gauge wiring and snagged an EcoSmart heater from Amazon.
The good? Yeah, it made hot water and aside from having to run that ungodly thick wire, it wasn'
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Hm, that's super disappointing. I had a gas powered tankless about 8-9 years ago which was AWESOME but no gas in this house so electric or nothing.
Thanks for the advice. I'll definitely rethink that one and take a much closer look before doing anything like that now. I was already iffy on it anyway but hearing electric having serious reliability issues is bad news I take very seriously.
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I've also heard a lot of good things about the Rinnai gas tankless units from folks I know who have them. Gas would've been my first choice as well, if it was available here.
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The other piece you need to be careful of is the rise they're capable of. Where I live, even a gas unit (I can second the generally-positive opinions on Rinnai from when I looked into them a few years ago) could only provide tepid water for a shower in the middle of winter; and the electric units couldn't even manage that. Annoying as hell for me, because I was trying to relocate an old (tank) water heater out of a closet to reclaim a kitchen cutout.
Much less of a concern for you in FL :), but depending on
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I have a different take. I now know that at least model has given one person in the real world a bad experience and deep diving into reviews will be important, particularly if that brand looks interesting for some reason and I'm also now warned to not take for granted the quality of any of these devices so when reading reviews that will be something I look for.
Everyone's mileage may vary but we're still all on the same road.
Re: My opinion of them (Score:2)
I can second the heat pump hot water heaters...
Got one... 7(?) years ago now and it saves a huge chunk of my electric bill. Especially in the summer, where we basically get free AC/dehumidification out of it in the basement.
The only downside is the rebound is slow, which can occasionally bite you. It does have a hybrid coil/compressor mode for "high demand," but I usually just leave it in heat pump mode unless we have guests staying over.
We paid about $500 more for it than an equivalent conventional electri
Re:My opinion of them (Score:4, Funny)
When it's super cold outside their efficiency of the heatmap approaches zero and you end up on emergency heat.
Then burn more fossil fuels. Eventually, global warming will make heat pumps work in your area!
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makes heat pumps a nonstarter ~6 months of the year.
Only 8/50 states seem to report an average low of get $500 electric bills
You don't run the emergency heat every single day
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Re: My opinion of them (Score:5, Informative)
heat pumps aren't really good during the fall-to-winter and winter-to-spring seasons. During the winter, heat pumps won't work.
Based on what? You know people actually own these things right? They're not new technology, like at all, its actually been around for decades, we know heat pumps work on cold days just like we know air conditioners work on hot days because they are actually the same exact thing. Seriously, the argument against heat pumps has never been do they work on mild days because thats where they work best, it's always been about the extremes.
Even just the most cursory of google searches you can find operating specs:
https://hvacdirect.com/aciq-2-... [hvacdirect.com]
Min/Max Outdoor Temp for Heating -2275
Min/Max Outdoor Temp for Cooling 5122
https://hvacdirect.com/mrcool-... [hvacdirect.com]
Min/Max Outdoor Temp for Heating -22F-75F
Min/Max Outdoor Temp for Cooling 5F-129F
Re: My opinion of them (Score:5, Informative)
Where are you living? The Yukon territories?
All but the shittiest, oldest offerings are good down to around -10 to -20.
And, again, you're only running defrost mode for a few minutes each day to remain frost-free.
Also, what''s your home envelope like?
If you're running one of these (essentially) cardboard-sheathed homes with absolute minimum insulation?
Yeah, there's no unit of any sort (other than setting the house on fire) that'll keep you properly warm on a continuous basis.
A well insulated, air-sealed home? One where you're losing minimal heat to conduction (and almost none to convection)? No matter what you use for power, you're fine.
Something Net-Zero/Passivehaus conforming?
You'll stay warm OFF YOUR PLUG LOADS!
As for the shoulder seasons, that's EXACTLY where heat pumps are in their element.
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Indeed, heat pumps are better with colder weather than they used to be. A 40 year old unit is a different story.
>A well insulated, air-sealed home?
Sadly lots of people don't have that option. In a region replete with brick-veneer houses, for example, insulated walls are often infeasible. Framing out, insulating, sheathing, and painting interior walls would be extremely expensive, and few people are willing to give up that square footage.
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I know people that use them in Finland and Norway. Outside of part of Alaska heat pumps work nearly everywhere in the USA.
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Re: My opinion of them (Score:2)
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most heat pump systems actually get their heat from the hot water heater.
95% of heat pump discussions are about air source pumps. Where are you getting this from? This is something I have rarely if ever heard about because it makes almost no sense from a plumbing and HVAC perspective. (Unless we are talking about some municipal style system)
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Where are you getting this from? This is something I have rarely if ever heard about because it makes almost no sense from a plumbing and HVAC perspective.
They might be referring to water source heat pumps [controlairsystems.com], which is something you really only see in commercial installations. I've only ever worked in residential, so I just imagined someone standing in the ice cold snow in their bunny slippers spraying down their outdoor unit with hot water from a garden hose.
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Re:More questions than answers. (Score:5, Informative)
The thermostat has since died and I've had trouble finding a replacement.
Unless the original installer botched the wiring, a standard heat pump capable thermostat from the typical big-box hardware store should work just fine.
The issue is that my heat pump is an air-to-air unit and so needs an outdoor thermometer to know if it is too cold to run.
Most heat pumps are designed to automatically call for the electric resistive heat if it is too cold for them to operate. Outdoor thermostats are typically used in dual-fuel installations in combination with a circuit to lock out the heat pump when it's too cold, because the system can be damaged if the heat pump and the gas/oil furnace's burner are running at the same time.
There is no harm in running an electric resistive heat strip at same time as a heat pump, other than the harm it does to your electric bill.
If someone told you their system "blew up", it's most likely because the original installer left a bunch of crud in the refrigerant lines during the install (did they have a nitrogen tank hooked up while brazing the lines?) and/or didn't do a proper flush with nitrogen and double evacuation to at least 500 microns of vacuum. Shitty hack job installations are the #1 killer of HVAC equipment, not cold weather.
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There's two ways a typical heat pump falls back to resistive electric heat. The first is that the outdoor unit itself calls for the heat strip to turn on. This is typically the white thermostat wire at the outdoor unit, but since there's no official industry standard color scheme you have to check the schematic to be sure. The outdoor unit will call for the resistive heat to turn on while it is in defrost cycle, or if it detects a condition where it should not be running (most modern units are already "s
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A heat pump thermostat has an extra terminal labelled "O/B" that controls the reversing valve (aka, heat or cold mode). It will also have extra logic to control the auxiliary heat strips as a second stage and offer the option to use the strips as an emergency backup if the heat pump should malfunction.
A thermostat built to manage air source heat pumps should have a means to connect an outdoor thermometer so it knows to switch over to emergency heat so as to avoid a malfunction of the heat pump. If the heat pump is run until a malfunction is detected (such as no temperature rise in a given time frame) then it is likely permanent damage was already done.
I am aware that a heat pump capable thermostat will have an "O/B" terminal. What is difficult to find are thermostats with terminals for an outdoor tempe
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If the heat pump is run until a malfunction is detected (such as no temperature rise in a given time frame) then it is likely permanent damage was already done.
A properly installed heat pump can happily run for days on end producing no usable heat, provided it's cold enough outside. Outdoor thermostats are simply for the comfort of the humans living in the residence, who typically don't want to wait for the indoor thermostat to realize it's not getting any warmer and to kick over to the 2nd stage of heating.
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A properly installed heat pump can...
I know what a properly installed heat pump can do, I had one. I can't find replacement parts. This tells me that the popularity of heat pumps is likely being overblown. If heat pumps are so popular then I should not have difficulty in finding parts for repair. If you believe I'm full of shit then provide links to replacement parts, specifically a thermostat that will do a proper switchover from an air source heat pump to auxiliary heat when the outdoor temperature falls below a set point. Prove me wron
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An Ecobee 3 lite will do the switchover just fine, I have one installed on my heat pump right now.
Ecobee 3 lite (Re:More questions than answers.) (Score:2)
I see no input for an outdoor temperature sensor on the therefore it is not compatible with my heat pump.
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It reads weather data, so unless you have some weird microclimate it should work.
"Compressor Minimum Outdoor Temperature:
The compressor will not run below this outdoor temperature. This is set to 35âF/1.7âC by default. Before adjusting this setting, we recommend reaching out to the manufacturer of your heat pump/compressor to inquire about the safest setting. Running your compressor at a temperature below what it can handle can damage the equipment and is ill-advised.
If you have a heat pump with a
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How much is "big furnace" paying you to come up with his drivel?
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If I'm spouting "drivel" then it should be easy enough to prove me wrong. I'd like to be proven wrong because then it means I can buy the parts I need to fix my heat pump myself rather than pay someone else to do it for me.
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There's probably tens of millions of heat pumps installed worldwide and you're the one single person who has this unsolvable problem?
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Prove me wrong. Pick a big box hardware store, go to their website, and find me a thermostat that has the ability to switchover to auxiliary heat if the outdoor temperature gets below a set point.
Again I'll admit it's been some time since I looked for such a thermostat so things may have changed. The professional installers obviously have sources for these thermostats but they do not appear to be items that are typically stocked for the DIY homeowner.
I suspect that if you look hard enough you'll find the
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Pick a big box hardware store, go to their website, and find me a thermostat that has the ability to switchover to auxiliary heat if the outdoor temperature gets below a set point.
They don't do that for the same reason thermostats also don't automatically order a cooler full of iced margaritas on a day when it's too hot for your air conditioner to keep up with with the heat wave. A thermostat's job is activate the HVAC equipment based on the temperature inside your home, not to predict how well it's going to work.
Here's your outdoor thermostat. [amazon.com] Typically they're used in conjunction with a fossil fuel board, but if all you want is your heat pump to fall over to auxiliary heat, it's
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They don't do that...
Mine did until it broke. By that I mean switch over to auxiliary heat, not order margaritas.
A thermostat's job...
A thermostat's job is to protect the air source heat pump from self destruction because it frosted over. I thought I'd check to see if there was a change in the heat pumps since I bought mine 15 years ago. That same unit is being sold so there's a need for thermostats like my old one yet. There's new model units on sale this year but they still sell the model I have, so maybe the new units have the "smarts" built
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That part isn't a "hack", that's how your issue is properly addressed in the HVAC trade. There is no established standard for an indoor thermostat to be able to determine the outdoor ambient temperature, so any manufacturer can come up with their own sort of implementation. I'm assuming you've seen the relevant XKCD comic. [xkcd.com]
Your complaint basically sounds like you're upset that you can't find an aftermarket stereo at Walmart that works with your Tesla. Although, in the case of your heat pump, I've already
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There is no established standard for an indoor thermostat to be able to determine the outdoor ambient temperature, so any manufacturer can come up with their own sort of implementation.
That's right, there's many different ways to sense outdoor temperature but few of the thermostats on the market have that feature in any form. I'm not asking for a thermostat that works with my old sensor, I'm asking for a thermostat that can have an outdoor temperature sensor attached.
Your complaint basically sounds like you're upset that you can't find an aftermarket stereo at Walmart that works with your Tesla.
Until a few minutes ago I couldn't find them anywhere. Someone was able to find a source and link to it but it is still an outdated model lacking in features that are seen in common, inexpensive, and "smart" thermostats I c
Re: More questions than answers. (Score:2)
Ecobee does this and is sold at big box stores.
https://support.ecobee.com/s/a... [ecobee.com]
Under "compressor minimum outdoor temperature"
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Earnestly trying to answer, is this what you are looking for or am i not understanding? This Emerson model has an optional outdoor sensor unit and from the manual it looks like you can program it from either the inside, the outside or a weighted average between the two:
Select Dual Fuel Temperature – With dF selected On and outdoor remote sensor available, select the outdoor temperature the thermostat will use to determine when to switch to gas heat and shut down the compressor. When the outdoor temp
An actual answer!(Re:More questions than answers.) (Score:2)
Holy shit! Someone actually found what I'm looking for.
While that is a thermostat that does what my old one did it is clearly an older model that lacks the features of the "smart" thermostats available today. It is also a thermostat that I'd have to special order, it is not something that any store around me appears to keep in stock. It is also more expensive than competing options with more features. The main unit, outdoor temperature sensor, and shipping, means it costs double what I could pick up at
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I think you're conflating the HVAC units with the thermostat's which in a lot of cases are seperate items from seperate manufacturers (Almost every home i've lived in had a Honeywell thermostat, they also have an outdoor sensor that works with their smart units)
Also I think what you are looking for is a somewhat niche case which is why it's not super common, you are really just trying to buffer the transition when the outside temp is too cold and the indoor temp has yet to drop enough to activate the auxill
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I think you're conflating the HVAC units with the thermostat's which in a lot of cases are seperate items from seperate manufacturers (Almost every home i've lived in had a Honeywell thermostat, they also have an outdoor sensor that works with their smart units)
I'm not conflating anything. The outdoor temperature sensor was clearly attached to the thermostat, not some control board in the furnace. I studied the installation manual for the heat pump and thermostat carefully when the thermostat failed so as to find an appropriate replacement. I had ample time for study because the failure happened in the winter so I hooked up a "dumb" bi-metallic strip style thermostat to keep the heat running and buy myself time for this study. It is clearly the responsibility
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I think you are using what I would consider a somewhat edge case in your example to malign the entire concept which is a little bit uncharitable. I don't know where this idea of "sprcialty thermostats" is coming from since for most residentials thermostats are something like 90% compatible since the HVAC unit is actually quite dumb be design. I have a Sensi which is pretty cheap for smart thermostats and it works with like 90% of units out the box with plenty of specific wiring points for heat pumps and 2
What free market? (Score:2)
... a tax incentive in this case is a pretty free market way to go about it ...
I believe you are confused on what it means to have a free market.
We've had government incentives on heat pumps for at least 15 years, I'm aware of this because I got incentives for my heat pump 15 years ago, and now people are excited when heat pump sales outpaced furnace sales for the first time. This is some kind of success story?
...it's rarity I think speaks to it being something of an edge case...
That's been my entire point. Heat pumps are the edge case. It's difficult to find thermostats built for heat pumps because they are an edge case. There's plenty of thermos
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Where is something i can read about this risk of a heat pump that "with no automated switchover then there's a risk of the heat pump grinding itself to pieces" and why does this not happen all the time when people are running heatpumps with Nests, Sensi, Honeywell, etc, since like 75% of Americans see snow and 50% see it regularly heat pumps should be destroying themselves left and right. If you can demonstrate how real the risk of this is when buying a heat pump and running it with any popular thermostat
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...doesn't make heat pumps as a concept a bad thing...
I'm not necessarily arguing that heat pumps are "bad" or "good" just that they are not popular. Pay people to buy heat pumps and the popularity will certainly improve. The "bad" about air source heat pumps is that they don't work when the outdoor temperature gets below about 40F. At that temperature they tend to frost up and stop providing heat. There's a lot of days below 40F where I live, and I'm not exactly living in the Arctic circle. Let's assume I am completely wrong about permanent damage to he
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gets below about 40F. At that temperature they tend to frost up and stop providing heat
Dude, its 2023, not the late 90's. Heat pumps work well below 40F nowadays with many working down to 0 and they don't frost up because they have defrost cycles like any commercial freezer or other below freezing HVAC unit does. This has been pretty standard for awhile, it's not uncoomon to find units rated to work well below 0 today. Efficency is a thing for sure but again, we're talking 200-500% coefficency to contend with for heat pumps.
going to start talking about backup heat requirements. Backup heat? Why does a heat pump need backup? Do they break often?
They do not break often, no more than a standard AC system since t
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Heat pumps work well below 40F nowadays with many working down to 0 and they don't frost up because they have defrost cycles like any commercial freezer or other below freezing HVAC unit does.
Technology doesn't change physics. Pull heat out of humid 40F air and you get frost. Keep running a defrost cycle to keep the frost away and at some point the heat pump is pumping heat out of the house faster than it is pump it in.
Do I have to remind you again that I own a heat pump? I've read the manual that came with the heat pump and they have charts in there on how the heat pump performs at given temperatures and humidity. These charts can be verified in by looking in physics and chemistry textbooks
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Keep running a defrost cycle to keep the frost away and at some point the heat pump is pumping heat out of the house faster than it is pump it in.
That's not how any of this works, no wyou are conspiracizing (heat pumps actually waste more energy and they only get used because of government) Think about it. There are plenty of people operating pumps in cold climates.
Do I have to remind you again that I own a heat pump?
Who cares, I own a dog, doesn't make me an expert on their biology.
Also it's just math, you can look up charts for CoP on heat pumps. Even at a low efficency the CoP (coefficent of performance)is usually over 200% and on most mild winter days it's 300-500%. BTU is irrelevant, CoP or eve
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Who cares, I own a dog, doesn't make me an expert on their biology.
Owning a dog won't make you an expert on their biology but you will know something about how much a dog eats. If someone comments to you about the costs of feeding a dog then you are going to have at least an order of magnitude idea on if the other person knows what they are talking about.
Also it's just math, you can look up charts for CoP on heat pumps.
Yes, I can look up CoP on heat pumps. Where I live -40F degree temperatures are common every winter, and CoP charts rarely go that low because at well above that temperature CoP gets to 100% and so is no better than resi
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BTU/hr is very relevant
Not in measuring *efficency*, which is a percentage which you can apply to the BTU.
If we assume a CoP of 200% and another common size of furnace of 120,000 BTU/hr the math works out much the same as above. My house has a 60,000 BTU/hr furnace but I know people with bigger houses and they have to have a furnace at least close to 120,000 BTU/hr to meet code. Code for these houses require 250 amp electrical service so take that into account on sizing things up.
This is kinda dishonest because it's BTU *per hour*. You can run a 40K heat pump for 3 hours versus a gas 120k for 1 and still come out ahead in terms of energy used, in fact most heat pumps just run more constantly constantly versus on/off cycles for gas and still come out ahead while also keeping the insides more evenly warm. Climate and temeprature dependant but again, BTU not really relevant here, efficency is what we
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This Emerson model has an optional outdoor sensor unit and from the manual it looks like you can program it from either the inside, the outside or a weighted average between the two
That's the fancier way to do it, but sometimes the existing wires aren't adequate and depending on how the house is laid out sometimes it's a massive pain to run new wires from the thermostat to outside. The way it's done in the trade is that since heat pumps call for auxiliary heat anyway during their defrost cycle, all the needed wiring is already present at the outdoor unit. You can then install a SPDT mechanical outdoor thermostat to automatically switch between energizing either the heat pump or the
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Thank you, I was trying to see if the sensor already exists on the condensor (it would make sense it would have one if not a couple, thermocouples are cheap) or like you mentioned, a setup that seems to operate independent of the thermostat.
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I hear these new fangled motorized carriages are more complicated than a horse and less reliable.
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A heat pump is just an air conditioner that can be run backwards. NOPE. Heat pumps are VASTLY more complex than air conditioners.
What? No they bloody well are not. They have literally one more major component (which is just a valve) and a couple more sensors, so a heat pump is barely different from an air conditioner. There's more math to be done in sizing components, but a basic heat pump is scarcely more complex than a basic air con.
A really good heat pump might have some automatic vents and a variable speed compressor, but guess what? A good AC has 'em too
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They have literally one more major component (which is just a valve) and a couple more sensors, so a heat pump is barely different from an air conditioner.
In addition to the reversing valve, heat pumps have:
A suction line accumulator (basically, a metal container for slowly boiling off refrigerant when the cycle direction changes)
An expansion device (usually a TxV or an orifice piston, for metering refrigerant flow into the outdoor coil during the heating cycle)
A defrost thermostat, timer, and relay (the timer and relay are usually integrated onto the main PCB in most units)
Generally speaking though, the increased part count usually isn't the cause of additio