I’m not sure about where you live but where I live (Canada) you can’t legally do your own heat pump installations. You need to be certified to handle refrigerants and that sort of thing.
I'm from the UK. I was under the impression you could do it yourself here but couldn't find a definitive answer.
It's absolutely something I wouldn't take on myself though. Changing a light switch or rewiring a plug, sure - but I'd be guaranteed to make a huge, expensive, inefficient mess with a project like that.
Yes, for example a mini split unit. You can purchase these at the hardware store and install them yourself. You just can’t do this with units that integrate into a central heating/cooling system which require the installation and charging of the refrigerant lines.
Just in case you don't know it, you may be interested in the videos about heat pumps, and other related technologies on 'Just Have a Think' channel https://www.youtube.com/@JustHaveaThink
I replaced an old condenser and furnace with a 21 seer 5 head mini split system last summer. It’s much quieter and allows everyone to have their preferred temp. My biggest surprise was the efficiency. I have amp meters on my mains, and I thought something was wrong when we first turned it on. The old condenser was 32k btu and the new one was ~40k, but it consumes 30% the energy compared to the old unit on average. This is all for AC. As for heating, my electricity bill is higher as I replaced natural gas… but I have solar. Anyways, heat pumps are pretty awesome IMO. On a new build I’d look at geo thermal heat pumps. Still a lot of theoretical efficiency to gain with improvements.
I have a ground source heat pump to heat and cool my home. If you can do it, it is the best system I've ever had. You've got to have enough room for the horizonal loop, or drill some wells.
It is a bit expensive to put in, so I wouldn't do it unless you plan to live there long enough to recoup the costs. If I were to sell my house nobody would give me a dime extra for it.
Well, I would! But I get the point, it's just chance of who's otherwise interested, and to actually get the amount extra they think it's worth you probably need two of them anyway.
The first house I built (designed, generaled and did a lot of the work) was super insulated. Selling it taught me that people just look at square footage and price. They aren't likely to know or care if is built better.
It was eye opening. I got a taste of exactly why builders build crap homes. Building code is the minimum and they build to it for a reason.
We are now friends with the people who bought it and several times they have thanked us for building it well. They didn't know what they were getting, but it is nice to see they appreciate it now - especially when the power is out and neighbors are crying about their cold houses and these lucky people are staying warm.
My third and final build I built for me. I never plan to sell. Even when my kids are gone and I only need half the house it would be very hard to find something to downsize to that would cost me less per month than I pay now. Ground source is that good.
It is crazy how cheap it is to heat modern houses compared to old ones, and this really ought to be factored into the price! The money you spend on energy is gone forever whereas your down payments go right into your equity, so most people should be happy to pay a lot more for well-insulated square footage.
Do you think this is really an information asymmetry problem? What if there was a standardized way to compare the cost of maintenance per M2?
Maybe it's cultural? We built a house in Ireland and our neighbours freaked out at the idea you could build a house without radiators, or heat a house without burning something (oil, gas, etc). It's been nice and warm (affordably) with just two air source heat pumps.
Interesting. I live in Dublin, we have a terrace house so it's not that large. When we bought it 12 years ago we did a complete renovation (decent insulation, new gas boiler). Since everything works, I don't want to rip everything out and junk it. But I was think about filling the south-facing roof with PV solar and installing two air-source heat pumps. I was hoping to cool the house in summer and heat it from March to October for free. Plus in the sunniest months, divert extra electricity from PV to the hot water tank. But I intended to leave the gas boiler in place as a backup. Maybe I shouldn't. Anyways, if it ever breaks down I'll just have it removed.
A standard to compare costs would be ideal. Right now in the US, your best bet is to repeatedly mention energy efficiency in the listing and use a realtor who understands how to market it. Provide monthly bills to show actual usage and use the analytics which most energy companies and smart thermostats provide. Being able to show 50% energy usage compared to average homes in your area helps homebuyers understand the benefits.
There’s a standard in the EU called Building Energy Rating (BER) which is disclosed when a house is sold. It’s a scale that runs from A-G, with A rating being the most energy efficient.
Anecdotally it doesnt seem to have a huge impact on the asking price.
There is a strong correlation between BER and the age of the house. In Denmark the majority of houses are in category D. Almost every house built after 2007 is >D and EVERYTHING that is built after 2011 is A or B, with a large majority in A.
My house is from 1935 and the statistics tell me that it is practically impossible for me to get the house above C. I think that it is theoretically possible but the required investment will be so big that it makes more economic sense to tear the house down and build it with modern materials and techniques.
Is there no equivalent to the Energy Performance Certificate[0] there? It’s not perfect, but it gives you a rough idea of how energy efficient the house is and where improvements should be made (e.g. insulation).
There could be an energy classification system to make it visible to buyers, to have something that uses the same scale to measure all houses so it's possible to compare. For example estimated average heating bill.
In Norway all real estate listings have an "energy classification" as one of the main data points. Example from a random listing I pulled up: https://imgur.com/a/0M9cNad
Of course, most people haven't cared that much about it. But it's changing with higher energy prices. I had a friend regretting buying something with grade F, for same square meters he pays like 10x the amount for heating than I do in my C apartment. (scale from A..G)
I think I would pay at least $5-10k more for a ground source heat pump on a house. The energy cost savings are insane. I think I would even prefer that over a solar installation.
Which model of indoor and outdoor did you go with? My research into multi split suggest that going with multiple mini splits is more efficient. There is also a concern that multi split is not eligible for IRA tax credit
I went with the Daikin 5MXS48TVJU for the condenser and 3 models of the head units. All Daikin. I didn’t want a bunch of condensers around the house, and I didn’t want to run power everywhere. I’m not sure about efficiency compared to multiple condensers or the IRA stuff.
Just as a heads up. Make sure you get a real pro to do the sizing on your unit.
I put in two Mitsubishi H2i systems last year and have had some pretty insane energy bills due to sizing them too large (A general overview of why here: https://carbonswitch.com/heat-pump-sizing-guide/)
Once I get my solar in place I won't feel too bad about this, but for now has been a bummer as was expecting a real efficient beast.
Around here (NE USA) oversizing is common with furnaces; the attitude is "better safe than sorry" where "sorry" means "contractor gets called because furnace struggles in mid-winter".
I replaced my old (95kBTU/hour output) forced-hot-water furnace and separate hot water heater with a condensing furnace about eight years ago. I got a heat loss calculation done, which concluded I only needed 59kBTU/hr of heat. It was a struggle to get a small-enough furnace installed; one contractor said he couldn't in good conscience sell me anything smaller than 120kBTU/hr.
My final system was 89kBTU/hr. A couple of weeks ago, in record -13°F/-25°C cold and high winds, it was burbling along at 60% power. Could have been even smaller.
We had an energy audit done a few years ago and the conclusion was that we needed about 40kBTU/h of furnace (upstate NY). We have an 80 (came with the house when we bought it). It’s actually quite hard to buy any gas furnace smaller than 60. But modulating gas furnaces seem to be becoming a thing now which is good and may make up for over sizing.
If you are oversized you may also run into problems of short cycling in warm weather, where you won't be able to dehumidify because it will be cooling too quickly. Who installed your system, they should be on the hook to fix it.
The article doesn’t make it seem like oversizing is a problem for efficiency —- it will just cause the units to turn off more frequently, leading to other issues.
We are running a large single head Mitsubishi ductless h2i in Montana. It easily provides most of our heating needs down to about -5F and some heat down to -15F, we have our old propane boiler / in floor system that kicks on when its really cold.
And it provided ac in the summer which we didn't have previously.
There are some downsides, it was expensive to put in and the outdoor unit is loud. While it does save us money, it probably wouldn't make sense as something that will pay for itself in heating costs with current propane prices and natural gas is much cheaper if you can get it. But definitely makes sense for new construction especially when paired with a wood or propane stove for back up heat in power outages/ambiance/quick heating.
It needs good air flow to work well and the noise is only really a problem inside the house in the room next to it. I may put some sound insulation on the wall at some point.
Really? I'm curious what brand of heat pumps these are. I have two air source units. One is a whole home Carrier Infinity unit (4 ton) and a GE single head ductless mini-split. The Carrier heats and cools our entire home save for a sunroom that's not ducted which is why we also have the mini-split. I never hear either unit.
As a Briton, I can't help thinking that once the unit is in place, with its double-wall sandbag enclosure (including 4' service space), I won't have any garden left.
Americans on this site always mention grid failures as a concern about electric heating/cars/whatever.
While I won’t claim that power failures never happen where I live, because they do…but they’re very very rare and short enough not to care. The only exceptions are major natural disasters like hurricanes.
Americans, why do you have such a terrible electricity distribution grid?
Power outages aren’t an argument against heat pumps anyway. Without power my central fan can’t run and thus my forced air natural gas furnace is dead in the water.
Anyway, where I live in Boise most utility outages are due to physical damage - whether that be animals, auto accidents, extreme weather (not “it got cold”, but wind gusts toppled a tree that brought down a utility pole), and fiber seeking backhoes. Even had the gas get shut off at my old house because an auto accident hit some equipment a street down causing a gas leak.
I will compare some nominal power inputs to add perspective about the dead in the water forced air furnace.
I will compare a nominal 3Ton = 36,000 BTU/h (10.55kW) furnace+AC running at about 1200CFM with gas fuel input at 45,000 BTU/h to similar heat pump system outputs and electric resistance heat.
The central furnace fan is probably about 1/2 horsepower rating (372W) and has some design tolerance built in where the brake horsepower is less than this. The heating output at 80% efficiency is 36,000 BTU/h (10.55kW). This output is constant regardless of outside temperature. This could be run with a small inverter generator or possibly a robust battery system in the 20kWh range with appropriate solar.
Note that the heating input for this size of furnace can go up to ~155,000 BTU/h (45.4kW) with only the same amount of fan power needed in the form of electricity.
Looking through Mitsubishi literature, a 3ton hyper heat pump (SUZ-KA36NAHZ) at 17f can deliver 25400 BTU/h (7439 W) of heat output with an input of 2490 W. You will need strip heat to supplement this output to make up the difference (10.55kW - 7.439kW = 3.1kW of electric heat) So total power input is 3.1kW + 2.49kW = 5.6kW input for 10.55kW output. This might be short a few hundred watts as you still have to run the fan. This could be done with a larger portable generator.
Electric resistance heat would need the full 10,550 W to equal the output and now you need a relatively large fixed natural gas generator and transfer switch.
My personal opinion is that a heat pump system for normal operation with a natural gas or propane furnace as backup emergency heating is a good option to cover emergency situations as much as possible without adding an additional separate system like a wood burning heater or similar device.
Every gas meter I've ever had has been purely mechanical. Have you ever seen one that needed mains electricity to work, and that acted like a shutoff valve when it lost it?
You’re right about the gas meter, but the town/city infrastructure necessary to pump gas through said meter does rely on electricity. They have backups, but for how long? Long enough to ride out most power outages, but nothing unexpectedly extended.
Many rural houses have tanks on site because there are no public gas lines to connect to. My house has a 1000 gallon tank and is not vulnerable to the above, for example.
It’s not bad where I am now in rural Montana but where I grew up near Seattle the power was off for a week plus most winters.
Lots of above ground power lines in heavily forested suburban sprawl means lots of branches in lines every wind storm and they (private) electric co has to visually check all of them before they can turn power back on.
Despite being much more rural the power coop that serves me now seems to never have an outage that lasts more then a few hours. Probally mostly because they have much less pine to check.
> The only exceptions are major natural disasters like hurricanes.
Which is the same as with us Americans.
My last apartment had a handful of power outages and all except one was due to weather. The exception was a transformer that exploded — which seems common as I’ve seen at least three just randomly go boom.
When you get major weather events, where they are pulling in personnel from all over the nation, is when people get concerned about electric heating because it might take a while to get to them.
Does American utilities not pay any compensation for power outages?
My local utility pays 50 EUR starting 12 hours after the start of an outage, and 4 EUR/hr after that. So a 2 day outage would pay out 200 EUR, and it all happens automatically.
There's no exceptions to this (only if you are at fault...), and this gets subtracted from their regulated revenues such that it hits the bottom line.
Naturally, most low voltage distribution lines are buried under ground
Not in Canada.. and this is the first I’ve ever heard of it.
Mind you here we have a much much larger country to cover in infrastructure , so it’s cheaper to run above ground.
Worth mentioning that I’ve lived in Alberta my whole life and I don’t remember a utilities outage lasting as long as 1/2 a day, so not sure a payout after that length of time would make sense anyways.
Our neighbourhood had an outage last winter during the -40 cold snap, and we were definitely at risk of water pipes freezing (gas fireplace was on, but without circulation it didn’t matter). The potential structural damage repair costs from outages up here would be insane, which makes me wonder if that’s part of why our grid seems so reliable (compared to other countries, anecdotally).
Where I'm at (Madison, WI), it's more like multiple times per year. This is a capitol city.
Recently, I stayed for three months on a mountain in Virginia. We lost power at least 6 times, usually for multiple hours. Once it was out half the day. There's a good reason the proprietor there keeps a backup generator on automatic failover.
I'm American, I think it isn't that bad, people are just like to whine and complain. America is also huge, so there is likely someone with a different experience and reason to complain.
My well pump is electric and I haven't been out of power long enough to be concerned about getting water.
We don’t. Power very very rarely fails, but when it has recently it’s been big infrastructures with flawed designs like the freezes in Texas, from what I’ve seen.
America doesn't have regular power outages; they're very infrequent and exceptional. However, when they do happen, they can be really big events, such as the big failure in the Northeast about a decade ago, and the infamous problem more recently in Texas during the winter. There's also local outages from natural disasters or extreme weather. Usually, very localized outages from storms (like falling trees) don't affect that many people and are repaired quickly. Outages from hurricanes, however, are bigger and take much longer to fix. What happened in Texas was just really bad planning and legislation, and only affected Texas.
It seems to depend on the area. In the SF Bay Area, wide scale power outages are rare. In Houston, most of my coworkers had small generators to keep their fridges and air conditioners running after a hurricane knocks out power.
Depends on where you are in the SF Bay Area. The hills in the region often have week long outages every year. I always know when the power goes out because the valley in front of my house hums with the sound of generators.
I mean, 10s of thousands of people isn’t wide scale? Weeks of teams of PG&E workers trying to restore power isn’t wide scale? What is the threshold here?
Most of our distribution network is above ground, so areas with higher wind and older infrastructure are more prone to outages. When I used to live in Ukraine, power outages were rarely due to distribution infrastructure (which was underground in most of the city I lived in) and much more likely to be related to generating capacity. We would go through periods of rationing where there would be frequent outages that would last a few hours, but rarely long enough for food to go bad.
If it doesn't have one already, look at installing a compressor blanket. This reduces compressor noise significantly. High end models generally have these already, but you can buy purpose built blankets for something like $70.
No, wrapping a compressor in a blanket doesn't make it overheat. Compressors are cooled by the refrigerant running through them, not through heat lost through the casing.
Pretty much every rural community will have one if not multiple propane providers. It generally is more expensive than natural gas, but the difference isn't astronomical. Heating with fuel oil is, by comparison, much more expensive.
Don’t know where you live, but here in NC propane is around $3.32 per gallon[0], equivalent to $3.60 per therm. My last natgas bill was $1.38/therm, almost a third the cost. In fact, propane is much closer in cost (per BTU equivalent) to fuel oil than natural gas.
For natural gas, is that only some itemized procurement price, or full price as delivered?
In the SF Bay Area, our last PG&E bill split across Jan/Feb was effectively $3.05/therm. The actual pricing in our bill reflects tiered pricing, with different tier thresholds in each month. The first tier covers up to 2 therms/day in Jan and 1.48 therms/day in Feb. The price tiers were $2.68..$3.06/therm in Jan and $2.75..$3.14/therm in Feb.
The bill also described $1.37/therm and $1.44/therm procurement prices for Jan and Feb, respectively.
Damn, I just got my propane tank refilled - it's a tiny 125 gallon one, mostly backup for our wood stove. We paid something like $2.40, and that's only because we didn't get a bulk discount most people get when they fill up the larger tanks sized for primary heat for a full season.
Propane is a bit more expensive then traditional electric heat depending on the year.
It used to be much cheaper so a lot of old houses that aren't near a natural gas line were built with propane heat. You might save $200-1000 a year by switching to a heatpump but that means 10+ years to offset a ~$10000 install cost for a large unit professionally installed with a new 220 circuit run for it etc so most people just keep paying for propane or maybe use small electric space heaters.
And if you are somewhere you need to worry about pipes freezing in power outage a while you are away or temps bellow the heatpumps minimum -15f range a propane stove is a nice option. Relatively cheap to install and they can be setup to run on a thermostat with no grid power.
If i was building a new house i'd go heatpump + a propane stove for back up heat and a dual fuel induction/propane range.
If you are into heat pumps, our team at Airthium (YC S17) is building an industrial heat pump able to reach 1000℉. Most HP are limited to 360℉ so it is a big deal in terms of industrial heat decarbonization potential (3% of the world's CO2 emissions).
See https://airthium.com
In case you don't get a reply from the parent commenter, it is basically putting many heat pumps together. So one heat pump steps the temperature up a bit, and your next heat pump takes that warm fluid and bumps up its temperature and so on.
You don't want to do large changes in temperature all in one go because it's inefficient - heat pumps love small temperature differences.
The no 1 obstacle in us adopting heat pump is the installation cost, currently there is no way you can recuperate the initial cost of replacing gas furnace with a mini split, because you can get billed 10k in labor for a 1.5 day work even the equipment itself cost only 2k.
You can not just send people checks and expect things can go well.
There are DIY mini-split systems that require only a couple of wrenches and drill.
Installed one myself in garage last year. Only paid to electrician to run 240v
The same reason can be asked why not just buy a couple hard drives and a server instead of going to cloud, because most people can not do much beyond their professions.
wall unit and outdoor unit come pre-vacuumed and sealed. lineset filled with gas and sealed. when you connect lineset to units seals are broken and gas fills entire system.
Every HVAC company I've talked to in Houston has advised me against heat pumps. Mainly, natural gas is so cheap in Texas that the cost benefit analysis doesn't work out.
Natural gas isn't that cheap everywhere. Texas is a big producer of natural gas so it's probably extra cheap there.
Where I live electricity has been getting cheaper faster than natural gas, so at some point it makes more sense to do a heat pump.
Plus if natural gas is cheap it can also be used to generate electricity without having to run and maintain natural gas lines to every house as well as electrical lines.
It's interesting math. You can turn natural gas into heat directly at around 90% if it's plumbed to the building. You can turn natural gas into electricity at around 50%. You can turn electricity into heat (resistive) at 100%. You can pump ambient heat inside using electricity at 300% (depending on several factors; adjust as appropriate).
Therefore the choice is between a gas furnace at 90%, or gas to electricity to a heat pump at 150%, if we care about the efficiency of gas usage between the two options.
But when comparing price per kWh of delivered gas vs electricity, ignore the 50% gas-to-electricity efficiency, because that's irrelevant. It's just the 90% vs 300%.
Therefore a gas furnace is cheaper if the delivered price per kWh of gas happens to be no more than 30% that of electricity in your area. Of course the rate for gas will more likely be in therms than kWh, but that's a simple conversion (1 therm = 29.3 kWh).
Not in Massachusetts. National Grid has basically doubled since last year. However a lot of towns have some kind of municipal service for a much lower price.
I would assume you have an AC unit as well as a gas furnace — but the AC unit is super close to just being a heat pump, so it’s worth considering replacing your AC unit with a heat pump at some point and turning off the gas furnace to see how the costs differ. Most likely for fairly long sections of the year in Texas you would easily heat your house with a heat pump at a low power usage since it’s not too cold out.
> assume you have an AC unit as well as a gas furnace
A typical Texas house has one unit that is both AC and furnace.
Most houses built in the last 50 years have central AC. Given that you'll have ducts, the simplest and easiest way to heat the house is to use them. In other words, it's forced air heating. It's really not a great form of heating, but it's adequate for relatively short, mild winters.
So if you replace your one AC/furnace unit with a heat pump unit, you probably won't have a gas furnace anymore to do the comparison. (Apparently, there is such a thing as a "dual fuel heat pump", though, which can heat with gas or heat pump. I'm not sure how much those cost.)
Another factor is that AC is the bigger concern for energy usage because AC is used much more of the year. So when replacing your system, whatever money you can spend on an upgrade, you're probably better off putting it toward improving AC efficiency rather than heat efficiency. Or toward something that will help with both, like insulation.
> Another factor is that AC is the bigger concern for energy usage because AC is used much more of the year. So when replacing your system, whatever money you can spend on an upgrade, you're probably better off putting it toward improving AC efficiency rather than heat efficiency.
Given that an AC is just heat pump, but with the hot bit outside, and the only thing needed to swap the hot and cold bits is a reversing valve. A high efficiency heat pump is also a high efficiency AC (that’s a very tautological statement).
So investing in improved heat pump for heating, naturally means investing in an improved heat pump for cooling.
The outside coil and fan also has to be sized for the worst case load that will be demanded based on seasonal climate. In some places this may influence the decision a bit.
If you need to replace your AC anyhow it probably makes sense to go for a heat pump unit vs just AC. But it probably doesn't make sense to throw away an otherwise fine AC to upgrade. I say this as a Houstonian myself.
Highly doubt it. The labor cost would probably exceed any savings and at the end of the day tech changes quick enough that you don't really want to be doing large service repairs on ac units, most likely more cost effective to replace the unit.
That'll change quickly. Texas is well suited for both solar and wind power, and the regulatory climate means they are being widely installed and will drive the price of electricity down significantly.
We got a heat pump last year and the heat pump + installation was around 14,000 Euro (minus ~2000 subsidy). Even with the current gas/electricity prices in West-Europe it currently doesn't work out last time we calculated, I think we'll break even when we are lucky. The price delta between gas central heating and a heat pump is still too large. (Though having a heat pump will probably improve the energy label, increasing the property value.)
However, our main motivation was to stop destroying the planet. Also within ~25 years, the government will require every building to be disconnected from gas (to achieve CO2 reduction goals). And from 2026 onwards, gas heating can still be installed, but it it'll be required to install a hybrid heat pump as well (a lower-capacity heat pump, where the gas furnace is a backup).
I'm surprised that nobody here has yet pointed out that if you have the money for the alternatives, installing new long-lived infrastructure or appliances that directly generate emissions by burning natural gas is unconscionable. Adding new renewable energy sources to an electricity grid is significantly easier than replacing ten million natural gas appliances scattered around the country. And removing all of those natural gas appliances will unambiguously have to happen in a world that takes climate change seriously.
This holds true even if your current electricity mix involves coal or other things worse than natural gas. Those plants will have to be shut down within the lifetime of your appliance or neither thing matters very much.
True, but solar panels are a capital cost (ie a one-time cost) whereas electricity/gas is a consumable.
There are lots of variables, but return on investment in solar is around 14% annually for me. It'll vary from place to place, so you need to do your own math.
It is interesting how the numbers work out in different places. Where I'm at it doesn't make sense at all. So much of my bill is just to have a meter and the per kilowatt rate is crazy low. Because of the high fee just to be hooked up the only way solar wins here is to get off grid - but winter kills that idea.
I don’t know why this is down voted. HVAC companies would actually LOVE to sell you heat pumps. But they don’t want callbacks and they don’t want word getting around they sell more expensive to install and run systems.
But in Texas, a heat pump wound probably be great. But yeah, natural gas is cheap.
This hasn't been my experience at all. I'm doing a pretty comprehensive remodel and swapping out 3 furnaces and I've done my own manual J/D/S calculations.. I've compared my cost of electricity & gas and while natural gas may be marginally cheaper if I were to upgrade to high-efficiency units, I've decided to install HPs anyways since our electric costs are much more stable here and our electricity is lower carbon. I literally can't find a company to install them. It has nothing to do with callbacks or expense, it's just that most of these companies are staffed/run by older guys who want to install the same massively oversized low efficiency furnaces and SEER 15 AC units they've been installing for the past 30 years.
The only people willing to install heatpumps are from an hour away and who spend their time building luxury homes. It's crazy to me that the rest of these guys aren't out there working with those Federal IRA funds and installing heat pumps left and right. We're climate zone 4 with a design temp of 6ºF, just about every modern HP will spend 99.9% of its time working at full BTU here.
I ran into the same thing when I built my house, where I couldn't find anyone local to take care of installing my split mini units without a wait of six weeks or more. I ultimately ended up purchasing a 25lb refrigerant tank, guage set, and vacuum pump to commission the units. I wasn't trying to DIY or save money per se, but this seemed to be the path of least resistance. Five years later all five heat pumps are going strong, this market dynamic doesn't seem to have changed much (here in Virginia USA) as I helped my neighbor bring her two heat pump units online in October 2022 after she couldn't get any of the local installers to schedule her either. I'm still puzzled why heat pumps are not dominant in the US market and why natural gas furnaces of any efficiency are still being installed, given that you can't power them from rooftop PV which is everywhere these days.
Watch the "Home Performance" channel on YouTube (see https://youtu.be/1Iiho2cm2LY) and note that there is a community of builders and installers who follow these practices and are likewise supporters of this channel.
Yeah I've considered this route... Mr Cool makes some precharged linesets for their heat pumps that are a still lower resistance path, but I'm at a bit of a loss how to take care of the refrigerant in the existing AC if I do end up DIYing it and swapping that unit out for a HP.
If the unit is still operational, it can usually be 'pumped down', which essentially means closing the 'out' valve and force-running the compressor to pull all the refrigerant back into the main compressor unit. You then might be able to take it to the waste facility, where they have people licensed to recover the refrigerant (for a fee).
I have my EPA cert, and I'd still probably go that route. The recovery pumps are expensive ($500+) and you need a recovery tank ($100), and then you still need to find somewhere that will take it from you. For a single job, it might be better to pay a HVAC company/moonlighting tech to do that part and do all the manual labor yourself.
Oh nice, that pump down process is something I hadn't heard of. I do have a good plumber and electrician, and our County has really good waste disposal options so that may work for me. Appreciate the heads up there.
I inquired about a higher seer unit when I had my system refreshed recently (I'm not in TX). The company I went with had the opinion that the higher SEER units are harder to diagnose and fix if you end up having a problem.
With the way supply chains are right now, getting a less common unit means if you have a problem, and you will because half the components are imported now, you're going to be sweating it out while you wait 3-6 months for a part, and that's if you can find a tech to come out and diagnose it properly.
If I lived in the deep south, I'd get whatever the standard equipment is and spend the difference on extra solar panels.
They make the most sense in a hot climate! You already have a heat pump, for air conditioning, why not use it for heating too and stop spending money on a furnace?
I'm up in DFW, I'd highly recommend a heat pump, gas is at an all time high, and not likely to come down soon. Running a gas fireplace a couple hours a month costs me 60+ dollars, I'd hate to think what a furnace would cost.
Well it depends what your optimising for. If you just want to heat your house in the cheapest way possible, maybe gas is better in some situations. If OTOH you want to signal to the market that you give a damn about climate change and act as an early adopter of technology that's going to be crucial part of net zero, then perhaps the equation is different. The benefits aren't just "a warm house".
Does the cost-benefit analysis really not work out even with the new 2023 incentives created as pay of the Insulation Reduction Act?
(Also, which is more likely in ten years: that natural gas will be cheaper than today, or that electricity will be? I think with the huge new investments in renewables, the latter is more likely.)
I wish heat pumps that were powered by natural gas were more common.
(I know everyone is expecting the entire grid to be 100% renewable on electric but it's going to take decades and by that time people can switch to new heat pumps. In the meantime we can save energy that way.)
If we want to move the needle in a meaningful way (CO2 wise), heat pumps and solar panels need to get better, cheaper, easier to install, and more available.
Where I live, driving a heat pump is more expensive than burning gas, from a purely economical POV. Our cost ratio per kW/h for electricity:gas is 3.5:1 right now, but COP for consumer heat pumps in real-world usage is just 2.6 (Yeah they all claim a COP of at least 3, but those are as realistic as ICE fuel economy ratings.) Those ratios need to at least match in order for a heat pump to make any kind of financial sense.
Those heat pumps for a mid sized house cost €15k right now. On back order for 12+ months.
Disregarding differences in NG price between utilities and households, I see different numbers than that. 60% efficient NG turbines, onto a 85% grid, and a 2.6 COP at home means no NG furnace can compete until the weather hits winter lows. I don’t see how it can make it worse.
Whenever anything related to heat pumps comes up, it always feels necessary for me to point out how behind the times the US is.
There are plenty of US climates that’d do just fine with a modern heat pump system. This wasn’t always the case admittedly, due to the lower lows. I know it’s a meme at this point, but even on HN I still see a lot of distinctly American ignorance and exceptionalism when people talk about this. I’m thankful for Technology Connections et al for putting the hard yards into getting some nerd circles across the line.
Why does it feel necessary when you recognize that the technology has only recently become performant enough for mass adoption on a continent with a different general weather pattern?
I have a Bosch BBVA (with auxillary heat strips) that was installed a few months ago that replaced an air exchanger from 1971 and a roof compressor from the early 90s.
I absolutely LOVE the Bosch system. It somehow manages to keep the heat more consistent at the set temp than my previous system. The Bosch system supposedly has some sort of power saving feature. We shall see how it handles the California summer.
As the adage goes, install quality is more important than the unit itself but so far I'm really impressed with the Bosch unit.
Presumably not the new idea that is discussed in the article though?
We bought a heat pump last year and we're pretty happy with it. The cost is comparable to our older (not very efficient) gas furnace. Temperatures here (Vancouver, BC) rarely dip below zero Celsius.
The only problem would he pumps that I've heard is that you have to apparently get a water filter here in the United States because depending on the water quality it could do tremendous damage to the HVAC system if it's not treated and that can be very expensive. The treatment part not the replacement part. Obviously that's expensive
We have recently bought newly built 2 story house (140m2) with the heat pump and foor heating completely insulated. Our electricity consumption is 600 KWh per month including heating end everything else. We keep thermostat at 20 degrees centigrade. Is the consumption too high or normal for the house of this size and configuration?
That sounds about right if you've got the thermostat at 20 degrees constantly; I live in a 700~ sq ft apartment and consume around 300kwh/pm; 10% of that is an inefficient NAS I built from old parts and I hardly use the heaters because god almighty are electric heaters inefficient.
Assuming you are in western Europe, I'd say for 140m2 it seems a bit more than okay, depending on how much windows you have. And depending how north you are. And depending on your usage (WFH, cooking...), it can be great.
Depends on the outside temp too. Best to monitor SCOP. My 180 m2 house with 18 degrees inside in January w ground souce heat pump (IVT Geo 508) and normal radiators ->
What is the impact on the immediate local environment? Drawing the heat out of the ground throughout the year surely means the ground will be colder going into winter. What impact does that have on plants, insects and small mammals when they are overwintering in the ground, etc? And what is the knock-on effect from that?
I have never heard this to be a problem for classic water water heatpumps. The hole goes straight down so the area impacted is quite small and the first part is isolated anyways.
Dunno how far down insects and mouses live?
In the article they mention heating the ground with 1.5m deep holes. I guess that would annoy the local life?
> Palmer has a heat pump in her U.S. home, along with a furnace as backup. “If it gets really cold, we can rely on the furnace,” she says
And boom, there’s the problem. I have a heat pump for some bedrooms on the second floor but only because I have furnaces heating the other side. I am impressed how the tech has improved though.
I think that's less and less of a problem. We just installed a Mitsubishi Hyper Heat, that's supposed to work down to -20⁰F without any auxillary heating.
Many other units have auxillary resistive heating when the temperature are that low, which is obviously less efficient than the heat pump, but is still better than needing to maintain a fossil-fuel furnace.
Mitsubishi now has a HyperHeat+ unit that goes down to even lower temperatures than before, and that's before you add the heat strips for auxiliary resistant electric heating. Watch Matt Risinger's "Build Show" channel on YouTube for recent announcements from the International Builders Show 2023 on this.
Are you Canadian? I had previously looked into heat pumps for cold climates and thought that it was economically not a great investment and required a gas back-up.
No, Massachusetts, so probably warmer than you, depending on where you are.
Even in Canada, though, I'd look into whether heat pumps with resistive auxillary heat are economical. If it only ever goes below -20⁰F for, say, a week a year, you'd probably still come out on top. And you'd definitely come out on top environmentally if your electricity is mostly green.
And with heat strips, a heat pump unit can continue to provide heating even below -20. Heat strips do make the heat pump more expensive, but I would wager they're less expensive than having a separate furnace.
Have a look what's being used in the Nordics in Europe. Sweden has 90% share of heat pumps for residential heating systems for example. I've got a Panasonic that heats to -35°C as advertised by the manufacturer and-40°C as tested in the lab.
To be fair, though, space heaters are dangerous in older homes with unknown electrical system quality. You're running a circuit at just shy of it's max load for potentially long stretches of time. Any poor connections (cough, backstabbed outlets) along the circuit or damaged wiring could result in a fire.
Aux heat for heat pumps (not mini splits) usually starts at 5KW (4 space heaters) and is a dedicated circuit direct to the panel and sized correctly. It's also contained in a steel enclosure with strict rules about distances to flammable items.
I’m not sure if you’re being literal or figurative, but most heat pump installations using forced air share everything with the furnace so there is no “side”. My thermostat just has a setting to use the NG furnace when it’s colder than X. BTW my heat pump is about 20 years old and works great in the range I have it set to operate in.
Literal. Did a 2-story home addition where the second floor had a heat pump installed since the existing venting system wound have been underpowered to support it and it would have been difficult to run vents there.
I wonder if it would be economical to make ground-fed heat pump that had piping built in together with house (dig out foundation, put piping for water-to-water heat pump, build house), for the colder places.
I'm told that (at least for the soil near my house) you want the ground source piping to make it down to the ground water because without that moisture the soil's capacity to transmit heat degrades over time.
You really need to tap into a watertable for the ground-loop to work. Otherwise it'll be nothing but a huge PITA.
And at this point in time, the best air-source heat pumps are good enough until -25C. Meaning that you get CoP more than 1 at this temperature. So this would work for most of the US just fine.
I have a “ground source heat pump” (a long pipe zig zagging under my lawn at about 2-3 foot depth) and kinda sandy soil and nobody mentioned no water table and it works great. Sand is not ideal but it’s not a blocker.
The most common heap pumps use bore holes straight down into the rock here in Sweden, but lateral installs are marginally better performance (sun reheats soil every summer) if you have a big garden.
Heap pumps dominate in Sweden so the installers have a lot of confidence and give good practical advise.
This guy is doing something similar with heat pumps and water storage - specifically utilizing radiator and boiler along with heat pumps: https://www.2040energy.com
We have a Nibe F470 air-to-air. Most of the time it's as loud as an old fridge. Not something you notice, since it in its own small room (where the gas furnace used to be). When it's freezing outside and the heat pump is working hard, it is louder, but you'd also hear the gas furnace under such circumstances.
I think by and large, it's more quiet than the gas furnace we had before.
I have the feeling that the next big thing we're going to see is cheap and easy ways to very effectively insulate old buildings. Then you won't need to heat or cool them very much at all.
I'm currently looking into getting a heat pump. Gree units seem both advanced and lower cost, so I'm trying to figure out if their quality is up to par.
Does anyone know if heat pump outdoor units are audible?
It would depend on the unit, but modern Japanese makes such as Daikin, Mitsubishi and Fujitsu are exceptionally quiet. I installed a Daikin multi-split system 10 years ago. My neighbour was concerned about the potential noise from the outdoor compressor. I assured her that it would not be possible to hear it from next door. On the final day of installation, the units were tested at full capacity. My neighbour craned her head around the wall and asked when it would be turned on. She couldn’t believe it was running full tilt. She couldn’t hear it at all.
It's going to depend on the model/manufacturer. Typically, the inverter based outdoor compressors are much quieter than the single or dual stage compressors that were common with the traditional American brands.
If you can find the detailed spec sheet or service manual for the unit, they usually have decibal ratings listed.
Well, they make some noise, but not as much as you'd think. I'm pretty sure that is on the spec of the various units so you can compare. We got a TOSOT and it's right out my office window but I can barely hear it (the indoor fan portion makes more noise in the house).
If you're in Canada you can get more than half your cost back through federal and provincial grants... So it actually ends up being a pretty sweet deal.
This paints heat pumps in a very rosey shade. The reason for heat pumps poor adoption is their poor performance and general inability to maintain comfortable Temps in colder climates and anywhere that weather and Temps change frequently. They also have a tendency to be unreliable. In an era where most home appliances have become less reliable, not more it is difficult to believe heat pumps would be the exception.
> their poor performance and general inability to maintain comfortable Temps in colder climates and anywhere that weather and Temps change frequently.
This doesn’t make any sense: heat pumps adjust seamlessly for changing conditions and the low temperature ranges keep pushing more and more of the country into the range where you can go all winter without auxiliary heat. A few days of electric heat per year are nothing compared to the savings the rest of the time.
As a renter of a home with a ground loop buried heat pump in Wisconsin I was very disappointed in winter. It was cold inside and there was no way to keep it warm. I wouldn't rent another house with a heat pump.
Aha. Yes I just have the above ground type. The only person I’ve met with an in-ground type wasn’t satisfied with his either but I figured that was because he was retrofitting it into an older home.
Just my point. Many builders over-estimate the efficiency of a heat pump when deploying the systems in places where it's -15F for months at a time and the frost line is 60 inches down. The label rating isn't going to be achieved. That can be fixed in time with better heat pumps made for actually cold places but right now there are still early adopter problems that don't apply to traditional furnances/heating.
They are globally ubiquitous wherever summer heat reaches ~30C/95F, and also in vehicles... just not so much in northern parts of North America and Europe.
https://youtu.be/7J52mDjZzto https://youtu.be/MFEHFsO-XSI https://youtu.be/7zrx-b2sLUs https://youtu.be/43XKfuptnik