Hello everyone! Looking to install heat pumps for our home. We currently have forced water baseboard heat fueled by an oil furnace. We're looking at a Gree system, which supposedly can heat down to -31 degrees. Obviously they won't be super efficient that low, but it seems that they'd fare ok in Maine winters (southern Maine) the majority of the time. My question is if anyone has experience using heat pumps as their only heating source, particularly in a single family home? We have a wood stove on the main level if we ever got into a pickle. We'd leave the oil system for backup, but they're noisy, ugly, and in the way along walls we'd like to place things along, so we'd love to remove the system entirely. A couple HVAC people I've talked to seem surprised we'd want to remove it, but to me there are clear benefits. Is this a bad move? Or more personal preference?
Comments
PencillCat t1_jcw4ju2 wrote
I'd install the heat pump and keep the oil as a backup for a few years to test it. See how much you use it and how you like it.
I've considered doing the same (I hate how loud the boiler is). I use a pellet stove as my primary heat source in the living room, and it's kept my house warm enough that I only used 170gl in 10 months (includes hot water in the summer). I'd like to eventually add a a heat pump or two as backup, and eventually get rid of the boiler.
I'd advise not to do anything drastic that can't be undone easily or cheaply.
Syrhen OP t1_jcw6l8b wrote
Unfortunately we're trying to finish the basement which is where everything is stationed. The layout works much better removing the oil tank, so doing it later means we have to use the "worse" floor plan. Otherwise I'd totally agree with your thoughts.
PencillCat t1_jcw7won wrote
Gotcha. Sadly I can't really offer any more advice. Everyone I know who uses a heatpump only uses them as backups, and for single rooms. The price hike in electricity has had people wary to use them as a main heatsource too.
I can sympathize though. I'm working on (slowly) finishing my basement too, and more than once thought "if only that dang boiler wasn't in the middle of the room." haha
Syrhen OP t1_jcw8ipk wrote
Right. The uncertainty in electric prices is one of my reasons for hesitation.
20thMaine t1_jcw90p5 wrote
If you remove the heat source for the baseboard make sure it gets drained at least. Don’t want those pipes to freeze in the walls
eljefino t1_jcwa3xw wrote
My heat pump is primary. I home-brewed a gadget based on an Arduino board that runs my boiler for a minute every hour when the outside temp is below 35, to keep the pipes from freezing, and to provide some heat to some closed-off rooms that don't get good air circulation from the heat pump.
One year in, and the system works well, and I'm saving real money.
Of note, I ran the boiler non-stop for that one 15-below day in early February. Gave the heat pump a break.
alpha417 t1_jcwdpuw wrote
removed oil from house last month. 2 extra low temp heat pumps do the heavy lifting. oil hydrionic system converted to gas tankless hot water with furnace backup for heat. keeps the original piping in place .
Majestic-Feedback541 t1_jcw7cvf wrote
I wouldn't rely on it for the only source.. having the woodstove helps,as long as you can keep your basement (pipes and all) warm too. When it got really cold this year, one apartment of my landlords froze up. That one apartment ONLY has a heat pump. They had to grab a bunch of space heaters for the tenant. And the pipes froze up too.
But, I mean, it's your choice, not mine
Syrhen OP t1_jcw8ee4 wrote
That's my worry, though if they really do operate at -31 surely I'd be ok? If the power goes out I'm hosed either way and reliant on the stove regardless.
Accomplished-Bee650 t1_jcwe61e wrote
“Operate at -31” at extremely low efficiency when you need heat the most. Is this really all that hard to understand? I’m an advocate for heat pumps but people don’t seem to understand that they are not miracles of science.
Majestic-Feedback541 t1_jcwj8g7 wrote
During that cold snap, the one in the apartment did not work. The Landlord had to run out and purchase a bunch of space heaters for tenants and pipes froze. So, no, they don't exactly operate on extreme temps correctly..
thesilversverker t1_jde368m wrote
They become resistive electric heat around -5/-10.
They work just fine, but costs more. If you hire a joe blow to size and install, and they dont do a schedule J, they might undersize, leading to freeze.
If you've got a cheaper, non-variable $/BTU option, keep it for cold weather. We dont live in the UP tho, they're fine as your primary in maine.
mainebitch1 t1_jdjbsz8 wrote
Wrong btu output drops massively when you approach the op limits my 36k btu rated to -30 puts out 8k btus at -20.
Try fuckin heating your house @-20 with 8k btus, so many uneducated jackasses in this sub its ridiculous. And i install them for a living
thesilversverker t1_jdjr3q7 wrote
Why the shit you people talking -30 like it's at all common? Yea, cap drops there, but we might get 8 hours of -30 temps in a decade?
Checked mine - i'm still getting nearly 30k/36k at -15f, the record low point this winter. Which was like maybe 8 hours. Since we expect these temps, any competent installer would size for the realistic scenario.
mainebitch1 t1_jdklk47 wrote
What kind of an idiot would have back up heat? ^this guy^^^^^^
BitOf_AnExpert t1_jcwmfml wrote
We did exactly what you're talking about. Removed a forced air furnace and ductwork and installed mini splits. Overall, it's been great. We have Mitsubishi hyper heat which are rated down to -13. First winter we had only the heat pumps, and had no trouble. As a backup we got a wood stove insert this winter which is nice for lowering the electric bill, but not critical. It's time to ditch fossil fuels.
Mixedthought t1_jcwdkw0 wrote
Have you considered something like the veismans combi boiler? It handles both water and heat. They run off either propane or natural gas and will hook up to your existing system. Small about the size of a water cooler and quiet. You would still be able to get rid of the oil tank, but you would have to add a propane tank outside which is perfect if you wish to get a gas stove or a generator.
Im in the same boat as you. The basement layout is awful to put in a finished basement in a small home so the only way to do it is to figure out how to remove stuff. We have contemplated the heat pump with a rinnai water heater and a pellet stove or the combi boiler and a pellet stove.
Syrhen OP t1_jcwe7kg wrote
Interesting thought. We've been thinking what we'd use for hot water if we remove the oil furnace.
bunnycricketgo t1_jcwkaz7 wrote
I've used geothermal for sole heart source, but even with that I had a wood stove; it works when the power is out and is nice to have when it gets REALLY cold.
Don't get a pellet stove as the backup: those need power too (for the feeder), but a wood stove just works with or without power.
AlternativeWay4729 t1_jcxme8r wrote
We have a 900 square foot STR that has a 25kBTU Fujitsu. The Fujitsu actually seems to work better when it's cooler. The remote set point has always been squirrelly, plus or minus 5F, usually minus. We tell the guests to set it to 74 to get 68F. It's a replacement remote, although it is the proper Fujitsu one. But I would never want just a heat pump in Maine with lousy CMP service and outages six to eight times a year. We put in a 10kBTU Empire propane monitor, runs without electricity, just enough to keep the chill off for when the power goes out in winter and we're not there and there's no guest, and a pellet stove for when there is a guest, no power, and we need to run a generator. Both were lightly used but secondhand and cost $500 each and then the stove pipe, etc. Pellet stoves pull only a few hundred watts, so we can still run the stove or hot tank on a 5kW genny (just not at the same time). We can turn the pilot on the propane monitor off after April and leave it off until November. We also put in a couple baseboards, which are quieter if the guest wants less fan noise. Kinda regret that once a month sometimes when the bill comes, because some guests will just run the baseboards and run up the power bill, but they never complain so that's worth something. Others would rather run the pellet stove, so we encourage that, and buy pellet for them no questions asked. It's important to know that the insurance company gave us not trouble when we said that there was both a heat pump and a monitor. That combination seemed to fit the bill. Twenty years ago they might have held out for a furnace.
AbrasiveDad t1_jcxp21p wrote
My house was built in 2018. 1100 Sq/ft 2 bed and 2 bath with a daylight walkout basement with a glass slider.
We have one heat pump in our living area that aims almost directly down our main hall to the bedrooms and bathrooms. The bedrooms all have electric baseboard. We have no other heat. The basement is entirely unheated and the main floor is insulated from the basement. We have a heat pump hybrid water heater in the basement.
In the winter I let the heat pump run on its own until it starts to struggle to keep up at that point I start turning up the electric baseboard just until it kicks on (analog thermostats in each bedroom). I'll play with the thermostats until the average house temperature is a degree or 2 from the heat pump set temperature.
The highest electric bill I've had in 5 years is probably just under $400. Last month I used 36KW. Highest monthly usage in last 3 years was 42KW and that was January of 22.
The no heat in the basement is going to get corrected with a pellet stove I got for free from my father. It gets as low as the high 30's down there but I've had no issues so far.
Prestigious_Mango_88 t1_jcxsam9 wrote
We did the same four years ago. Mitsubishi system, left the oil hydronic system in just in case. Haven’t needed it, and finally pulled it out this year. We have a wood stove that we used the old oil boiler flue, so that’s our emergency backup (and nice on those really cold days). If it works in our 1791 farmhouse, it should work for anyone!
SuccessfulCow5557 t1_jczlmjn wrote
We put in heat pumps this winter for a backup heat and dehumidifier option in summer. The basement was much cooler without the furnace and pipes carrying hot water all the time. Anytime it was below 0 degrees the heat pumps could not keep up, they’d work but if set at 68 the space would be 58 and they were working hard. Burned a lot less fuel but had a very cold basement and some comfort trade offs on the extreme days.
thesilversverker t1_jde3kd4 wrote
> Anytime it was below 0 degrees the heat pumps could not keep up, they’d work but if set at 68 the space would be 58 and they were working hard
This means whoever sized your system did it incorrectly - same thing would happen with wood, natural gas, or oil.
floralwhale t1_jd0f4db wrote
We're in Westbrook. Had two heat pumps installed last summer (one in the primary bedroom, one in the living room). Our plan is to test them out for a few years before removing the oil heat. So far so good! Our heat pumps have gotten us through winter on their own.
wakman33 t1_jd4a9g3 wrote
The wood stove will save your ass if it gets really cold or the power goes out. I put in a heat pump, got rid of oil and kept the wood stove and pellet stove for power outages and extreme cold. It works great. So the heat pump isn't really sole source of heat. You'll be fine.
mainebitch1 t1_jdjb8j0 wrote
No if it gets really cold they wont cut it you need backup with heat pumps a woodstove would be fine
eastforestwest t1_jcw2i35 wrote
I think it's foolish to remove a system that works rather keep it as a good, proven backup