Should I go heat pump only?
Hi all,
I am in the middle of taking bids with my local HVAC companies and am looking for someone to nudge me in one direction or the other. For background, I bought my house in western Michigan, right off the lake Michigan coast near Grand Rapids, last Fall. My home inspection made it clear the AC would need work and I haven't started to feel the need for it until recently. I called an HVAC company out and when they said the unit was 25+ years old, I just told them to forget about even fixing it because it would be at least 10% of the cost of a new unit and still way less efficient.
So.
My natural gas furnace is also ~20 years old and the first HVAC guy said that if it broke down, it likely wouldn't pass a safety inspection. They said something about how the coils being dirty or positioned someway or something, I can't really recall 100% what the issue would be but the gist that I got was that when it breaks down, whether it be 1 year, 2 years, or 5 years, it won't be worth fixing or it will be unfixable. A new AC would be ~$6500 and a new furnace would be ~$7000.
So I started up the conversation towards installing a heat pump unit in instead of a standard AC unit. My initial thinking is that when the furnace goes, I have the back up ready to go instead. Now a heat pump unit is going to cost me around $2000 more. I don't think my plan will be to ever install a replacement furnace. Depending on what the solar assessment says, evaluating both ground mounted and roof mounted solar, will tell me how worth it is to go that route and have discounted or free heating and cooling.
Where the calculus gets tricky for me is there is the Inflation Reduction Act which will give me a $2000 tax credit for a heat pump. But that will come with buying a more expensive, and efficient unit, and I believe I will also have to completely get rid of the furnace I currently have since the total home system has to meet the efficiency standard. In addition, last month I replaced my fuse box with a 200 amp panel and if I meet the requirements to get the $2000 tax credit, I would also get $600 tax credit for the panel since I can tie them together.
All in all, I am looking at getting a more efficient unit for roughly the same price as the less efficient unit but without the natural gas furnace as either main heating, or back up heating. My hesitation is that natural gas is so cheap that it doesn't make sense financially to go heat pump only unless I have renewable energy to pair with it. But maybe I am just overthinking it? And maybe I have gotten something wrong in my calculations?
Any advice or clarifications would be greatly appreciated. I have one more quote coming this Thursday and I hope to make a decision by Friday to get the work started
Short answer: Make sure your HVAC installer knows what they're talking about, then go full heat pump.
It would be wise, given your location, to have a backup heating method for those cold days, when heat pump only might not suffice. If I were in your shoes, that would probably mean a wood pellet stove of some sort. A gas fireplace insert would probably suffice though.
While you're right that gas is possibly cheaper when you don't factor renewables, doing it this way puts you on a nice stepping stone to add on some solar panels (or a wind turbine, if you can), which definitely helps.
For those horrid spring/fall days where the temps exist in that space of 'cold enough to want heat in the night and hot/humid enough in the day you want AC', heat pumps in auto mode are godsends.
Hmmm, yeah that's a good idea.
I do actually have a random wood burning stove in my garage that came with the house. It isn't hooked up but I could look closer at it tomorrow to check it out. Home insurance probably wouldn't like a wood burning stove though...
I also coincidentally do have an inoperable gas fireplace. I didn't bother doing anything with it because I didn't care when I moved in but I will do more research into one that can operate as a mini furnace with a blower, if those exist.
Odds are you'd be just fine with some resistive heaters plugged into wall outlets on the absolute coldest days of the year. Though I don't think you'll need them since modern heat pumps work well even below freezing. A more expensive option would be a geothermal heatpump, but that's almost certainly overkill.
I've got a closed loop geothermal heat pump in my home. In the same year, I installed solar panels. Other than the significant cost outlay to do it all, I've paid ... $0 for all my heat, cooling, and most of my hot water over the course of the ~18 months since I had them installed.
I have a variable speed compressor in my GSHP such that it always uses the lowest power to heat or cool my home. The most watts I've ever seen it use to heat my home was 1700. It's insanely efficient. I keep the thermostat pegged at 70 year round and live in supreme comfort. To heat my home to 70, while it's 15-20 degrees F outside for less power than it takes to run my microwave is absolutely bonkers.
Because it's ground source, and the compressor lives in the basement where the propane furnace lived before, I have zero issues ever with the idea of outside temperature affecting the efficiency or functionality of my HVAC.
I'm a bit resistant to having electric only options for now when I don't have solar, and solar may end up being unviable where I am. The rough calculations that I have show that I would barely meet my electric needs in winter if I were still using natural gas as my heating option, so I don't have high hopes that it will work out.
I also have very limited outlet options in my home unfortunately. I was going to push for a whole home rewire at some point in the next 12 months and maybe then I would feel more comfortable.
You may want to look at wind options (disclaimer: this is not an endoresment, investigate local options) if solar isn't viable (and you're far enough north that winter solar is basically a rounding error). If its anything like living near the ocean, you're gonna have a pretty solid breeze more often than not.
There is a decent breeze on-and-off throughout the day, but most noticeably there seems to be a lack of wind overnight unless we have some weather fronts smashing into each other. On top of that, I am in a fairly suburban area. I have doubts that ground mounted solar would be approved on my home, let alone my own
personal wind turbine.
I know New Jersey has laws that say localities can't put overbearing restrictions on installing residential wind turbines, but can't speak to your locality sadly.
Hey, we live in the same area!
Important question: when you say you live right off the Lake Michigan coast, are you literally on the coast / beach line?
I ask because I used to do residential cable install there, and houses right on the coast (or very close to it) have specific issues due to the wind and basically getting sandblasted. This would be relevant to both your HVAC and solar - solar would be prone to degrade faster, as for HVAC you would want to plan out having your external heat exchanger on the side of the home facing away from the lake.
Other than that, some things to look at:
Be skeptical of people who suggest something would be 'unrepairable' and encourage you to spend a great deal of money. I've been given the same advice by an HVAC tech that I called out just to top up our refrigerant after doing my own maintenance and repairs - there are often commissions involved in making a sale like that, or they are being pushed to make a quota of sales, things of that nature. Look at online reviews, get a second opinion, that kind of thing. Worth spending the smaller amount to make sure the information telling you to spend a much larger amount is not biased. Also, I have a large helping of distain for the word 'unrepairable' in general because of the described profit motives involved.
Next: tax breaks. There are tax deductions to be had for making energy efficiency improvements to your home OTHER THAN /IN ADDITION TO THE FEDERAL TAX BREAKS. I looked it up, Michigan will be rolling out some new ones as part of their funding from the Inflation Reduction Act: link here. I'm pretty sure there are already some tax breaks in effect, but the IRA funding should be more and it looks like the timeline is to put them into effect and make them available come October this year. It looks like (currently, tentatively) the max rebate for a HVAC heat pump is $8K. Note that is max, no idea what you would actually get. Oh, and look into (and maybe ask a tax consultant?) if getting solar and a heat pump in the same year would conflict in terms of the max tax break you would get - I don't know that they would, it's just something that occurs to me to look into. If there is some max energy efficiency tax credit per tax year, you might want to space it out over 2 years.
Look into the warranty terms on anything you might get. It's a big purchase, don't just ask 'how many years', if it's worth spending thousands (over 10K???), then it's worth a couple hours of reading soul-destroying fine print and doing some web searching so you really understand what you are getting in terms of support and coverage in case something breaks.
Technical discussion on heat pumps and very cold weather: Matt Ferrell covers this issue in this video, he also has another video about cascading pumps that deal with extreme temperatures by doing multi-stage heat pumps. Basically, there have been advances in heat pump tech and it has gotten better. Just look into the specifications of the models available, or look into ordering a newer-gen model that can soldier through the cold days.
That's all I can think of at the moment for advice. Hello kinda-neighbor!
My understanding regarding cold-climate heat pumps, supplemented by my practicle ownership of a new-but-not-cold-climate, good to about 10F:
While they can operate at full capacity, their efficiency has a fast dropoff below 40F or so, and is worse than electric baseboards below 25ish.
Having even a small supplement, especially a fuel-based one (for emergencies due to grid failure), can provide great savings on the coldest days.
Running my gas fireplace insert when temps are below 30 for me, it'll cost like $20 more in gas, but save me about $80 in electricity (0.22/kwh) due to not needing as many defrost cycles.
Yeah, a lot of it comes down to a case-by-case decision based on what model heat pump is being considered, the relative cost of gas vs electricity in the location being considered, expected average and extreme yearly temps, etc.... definitely no real hard and fast this-is-right / that-is-wrong answer on full heat pump vs heat pump with gas backup (or hybrid system that is less designed as backup and more designed to be programmed to switch over to optimize total cost of heating).
Hi neighbor!
I am just over a mile from the coast so no beautiful views, but I do get a nice cooling during the summer/warming during the winter effect that is readily apparent when going to Grand Rapids for the day.
I was pretty skeptical of the comment about repairability for current furnace, but my understanding was their concern is not really about not repairable, but more will it be worth it to fix when it does break. If I recall the concern correctly, they were concerned about my heat exchanger. They mentioned particulate matter falling onto the heat exchanger due to its age and the specific model I have. Fixing that particular piece of the furnace could run me ~25% of the cost of a new furnace, while not having nearly the same amount of efficiency.
Thank you or the information about the tax breaks! I don't know if I would qualify for any more than the federal ones I found. Generally, I don't fall in the income tax bracket where I would receive the highest amounts available. Regarding solar, it is definitely not happening this year. Maybe next year, but more likely two years from now. It is unfortunate because solar panels might be more expensive in the coming years due to the tariffs on Chinese solar, but maybe if Biden gets re-elected we will have more tax incentives for the US-produced stuff.
Ah, the sweet spot! Nice. That buffer against high highs and low lows, while still being away from the harsher wind aspects is very desirable. I always enjoyed the days I was routed to the Spring Lake / Grand Haven / Holland areas, especially when I was at a house close to the coast. Great air there.
Oh, and take care with selecting the company to install your solar. There is incentive money out there for those companies, and there have been known cases of bad actors essentially scamming customers to get them to sign off on solar installs, not really caring about what the customer actually wants or install quality, and then walking away with the federal solar install incentive money while shafting the customer in various ways. Definitely look for reviews on independent sites about any company you are considering.
I don’t know if the tradie situation in the US is anything like Australia, but it might be worth asking people in adjacent fields for reputation — for example, I can imagine builders and/or electricians might rub elbows with solar installers and therefore pick up on reputation through hearing complaints or praise from customers?
This makes sense to me. Anyone who would be called in to remove or repair a crappy or incorrect install, so Electricians and Roofers are the ones that come to mind. You would just need to stay aware of potential bias from profit motive with these groups as well, but that doesn't mean they aren't worth talking to for information.
Heat pump efficiency rapidly decreases as temperatures go below freezing. At about 12°F they basically just start to produce cold air and you will need to supplement with either Electric or Natural gas. Since you live in the northern US, you should be buying a combo unit that allows you to switch over to an alternative source when the temperatures get below the point that heat pumps are viable.
If you don't want to get a full combo unit, you at the very least should expect to need to buy a bunch of electric baseboard heaters for individual rooms (which could get complicated if any rooms are on shared circuits). I think this is likely to be the most efficient (but less convienient) option.
All of that said, heating with a heat pump is something like 300% efficient vs the 100% efficiency of a modern baseboard heater or the 98% efficiency of Nat gas. So, you get a huge energy savings during the majority of the winter and only should have to supplement with alternative heat during the really cold periods in late January / early February.
Just want to let folks know that there are new "cold climate" HVAC systems out by Mitsubishi, and some coming out soon from Trane and Carrier, that provide 100% of their capacity down to 5F (-15C) and continue operating down to -13F (-25C) and possibly lower. Their efficiency is incredible and for anyone looking at running a whole-home electric system, I'd strongly recommend these new "cold climate" units.
I recently had the Mitsubishi H2i system installed at my place and it's a profound improvement. The difference is like driving a modern sports car versus a sports car from 50 years ago. There's a lengthy-ish comparison article here that's the best I can find on short notice.
The drawback is that the default air handler (the part inside) doesn't have resistance heating. I think it's an option, but if you don't have it installed you have literally 0 heat as backup for any scenario where the heatpump isn't able to function. But in those cases you'd typically switch to baseboard or a floor-standing heater. Apparently the Canadian market has units that will go to -17F (-30C) and below.
Also, Mitsubishi has an article on why the SEER2 rating doesn't matter anymore.
So far, out of the two HVAC people that I have talked to, they have been pushing Goodman units and haven't mentioned cold climate as a selling point for them. I will do some research on my side to find a contractor who specializes in these units.
To add to this, if you're going tge heat pump route electric backup probably makes the most sense, especially if you're adding solar and potentially battery storage since those then can supply your heat. That way you can always maintain a minimum temperature in the whole house to keep pipes from freezing.
That being said, consider using space heaters or zoned baseboard heating in the rooms you spend the most time in on really cold days where the system will switch to it's backup heat. No sense in heating the whole house up to 70 when you can keep it closer to 65 (taking load of the central system) and only use resistance heating in the spaces you need it. Will help reduce the amount of energy you need and stretch your battery (if you get one) while on the backup heat.
Technology Connections made a great video about bad HVAC practises carrying over to Heat Pumps: https://youtu.be/DTsQjiPlksA
This is the video I was going to dig up and link. Tl;dw: yes, go full send on heat pumps. Consider supplemental resistive electric heating if you live in a place where it gets very cold at winter (which OP does); it's a lot simpler and therefore more reliable than a combustion-based supplement.
I installed an AC and heat pump in my last house, in the northern US. The AC side of things is standard regardless of whether you have a heat pump. The heat pump basically let's you reverse the system.
Go duel with a heat pump and gas furnace. Climate is getting more extreme; hotter summers but also colder in places during winter. Even the best, cutting edge, fully communicating systems struggle to keep up when it gets close to zero F. I know because I installed a high efficiency unit, and even when it can keep up, barely, it is cheaper to use a different heat source and not run your blower unit running 24/7.
You lose heat during a cold snap, and you run the risks of pipes bursting if you don't have a backup heat source, especially if you happen to be traveling.
Me 2, that was my experience. It's still worth it given how much gas pricing has risen. In what I would consider temper weather the unit works well, once that sweet spot is moved then the alternative is better. One thing to consider in this setup is the automation. Gain the efficiency of both solutions without having to run around trying to do it yourself.
If you really want a Heatpump in Michigan, I'd go dual fuel. Heatpump coupled with a furnace. It would fit right into your current setup, no need to run 240v or have some auxillary heating method installed elsewhere.
The heatpump runs when it can keep up, and if it can't, the furnace will run instead.
I'll add on that I remember this guy is an HVAC installer, so I'd trust his words over most others.
I wasn't even aware of duel fuel furnaces.
Most people who have them don't even realize they do, because visually they're identical to a conventional system. Only way to know for sure is identifying the dual fuel control board, the thermostat wiring, or seeing the reversing valve in the condenser.
My hesitation and reservation is the price I was quoted for 17.2 SEER heat pump and 98% efficiency furnace was nearly $19,000. Granted, I can just ride the existing furnace until it goes out and be out of pocked ~8k-$9k just for the heat pump install, going for a lower efficiency unit and forgetting about any tax incentives from IRA.
Are there any downsides that you can think of to just going with a heat pump only, and then fixing/getting a gas fireplace that I could use to supplement during extremely cold weather?
Also, any specific brands to avoid?
Cost? No idea what your fireplace situation is and how much it would cost to have one installed / repaired if you have one, so I don't know if that would be close or not.
Also no idea how big your house is. A furnace would provide central heating, I don't know if a fireplace would be enough to warm you house, or just the room it's located in.
Brand really does not matter. Every brand has some kind of prevailing issue of one kind of another. The install itself is going to affect your system more than the brand.
If you want to only run a heat pump, make sure you get one big enough, and maybe bigger than is theoretically needed.
Before it hits the point where it literally can't keep up with the heat loss, it enters a regime where it needs to run 25/50/75/100% of the time, blowing air just slightly warmer than the ambient air at a speed that can make it feel cold and drafty wherever the air vents point. Being blown on by 67 degree air in a 65 degree house half of the time is no fun.
So talk with your installer in detail about the design goals of your system, and maybe make them measure how fast your particular house leaks heat.
Yeah, that's in line with what I have been told. I currently have a 2 ton AC unit and the heat pumps being suggested are at 2.5 ton or 3 ton. I am 90% sure I will be going with Carrier/Midea 38MURA with the associated air handler. The performance seems good enough to fit my needs and I at least have until January/February next year when a potential cold snap comes in that I can get my fireplace up and running, unless I see some estate sales this summer offloading some other heating sources that I can purchase on the cheap.
I have one more consult this morning but should be able to make a decision by Monday.