Well, I don’t know anything about that specific heat pump, but we installed a new heat pump in our house 2 winters ago. We are in north Missouri, where we have real winters with days of below O° not unexpected. It’s a Bosch Split System Heat Pump.

The heat pump keeps us nice and cozy. It has a backup system BUILT IN to produce supplemental heat when the air outside is too cold. I don’t remember if the supplemental heat is fueled by natural gas or electricity. (I think it’s natural gas.)

Thanks littlebug! Our goal is to get completely away from gas. But we have the luxury of a warmer climate. 0 degrees would be freakishly cold here, not something we need to design for.

He's a little out of date with info on heatpumps (especially Mitsubishi minisplits) and I'm not sure I buy his story of dry weather killing efficiency(!) But backup (auxiliary/emergency) heat is advisable with any heatpump. In your climate, you won't use it very often so just get resistance electrical strip heat backup.

Daikins tend to be expensive for what they are. They are inverter condensers (they are based on minisplit condensers) but for some reason, their ducted air handlers are two stage (I'm assuming based on a Goodman ducted system). I'd get a single or two stage Goodman heatpump system with electric resistance backup.

We're also in the Seattle area and are getting a Mitsubishi hyper heat installed. They say we don't need additional heat strips.

Thanks sktn77a! That's helpful info. We're getting a Mitsubishi ducted system, not a minisplit.

Pgjs, also helpful info, thanks. Hope your experience is a good one.

The winter design temperature for the Seattle area is about 27 F degrees. Going below the freezing temperature happens occassionally. I am not an expert about the Mitsubishi heat pump you are installing. I assume it will need to go through defrost cycles when ice accumulates on the outside coil. During the defrost cycle the heat pump will reverse itself and work as an AC to send the heat to outside coil. The heat pump will turn on the back up heating strip to warm the cold air when in the AC mode. Ask your installer what will happen during a defrost cycle if you don't have a back up heat system.

1. Thanks, @mike_home! I will definitely ask about defrost.

Another factor to consider that hasn't been mentioned is your personal use pattern.

So long as outdoor temps are within their designed operating range, a heat pumps work fine to maintain a set temperature. To raise the indoor temperature more than a few degrees can take hours and hours.

Do you use a setback thermostat? Do you like to turn down the temperature setting during sleep hours? Do you turn down the temperature during the daytime or when you'll be away from home for more than a few hours? If so, simply relying on the output of a heat pump will not be sufficient because of the time needed to respond to an increase in temperature setting. Supplemental heat, either in the form of a furnace or heat strips, will add to the comfort performance of your system.

As someone who lives in a mild-weather area but with some hot days during which running an AC during the late afternoon is essential, I choke on the notion of having an AC system (which is what a heat pump is) running for hours on end (and with heat strips at multi kilowatts per hour), day after day. Unless you live somewhere with cheap electricity prices, you won't be happy with what your monthly bills will look like. If you have gas available, that's the way to go, in my opinion.

Price it out and see what you find.

Thanks Elmer. Your points on use patterns could be an important factor on choosing backup heat. We're committed to a heat pump though. Getting rid of gas in our home is a priority.

"To raise the indoor temperature more than a few degrees can take hours and hours." What?? I could get my ductless Mitsubishi cassette cranking and changing the temperature by several degrees in 10 minutes. Also, I'm just now starting to use them for heat but all summer long I kept them on 24/7 without opening a window with my electric bill averaging $165. Then a brutal heat August came along and the bill jumped to almost $400 but I'm talking 3 slim cassettes running non-stop night and day maintaining 70 degrees during the day and 68 degrees at night... I never turned them off. From my understanding my Edison rates are the highest in the country.

You can't go wrong with Mitsubishi. Use a certified installer and it doubles the warranty. Also, if you like technology there is an add-on piece that uses infrared that will track your movements around a room and redirect the vents so the cool or hot air is on you at all times.

The new heat pump GE Ultrafast combo Washer/Dryer is a must if you want to dump using natural gas. That machine changes the way I do things entirely since it is both a washer and a dryer and is more efficient then my stackable ever was. My bill shows that a big load costs about 25 cents to wash and dry... in under 2 hours. Its amazing.

Apples and oranges, paul f. You mention Slim Cassettes - that's a mini split system. The OP is talking about a ducted conventional split system.

You are right... his set up would not allow heating and cooling of one room. Both are heat pumps not exactly apples and oranges. The BTU's would be the same.

The outdoor temperature is 25 F degrees it may take a while to recover from a temperature set back if there is no auxillary heating available.

Stax, the climate here has changed a lot just in the 18 years we've lived here. Last year we had a week of 90 degree heat--IN OCTOBER. And a lot of 90+ days all summer before then. The year before that was the "heat dome" year when it hit 110 in June. And those were both La Nina summers, which are supposed to be cooler on average. This year will be our first El Nino in 4 years--it's going to be hot. AC is a lot more useful here than it used to be.

Paul F, thanks for the washer/dryer tip! Our electric Whirpool units are still going strong. I'll take a look at heat pump units when they fail. Next research project though will be a heat pump water heater. That's the only remaining gas appliance in the house.

When you have an all-in-one washer/dryer, it takes twice as long to do laundry because only one load at a time is being processed. You can't move the first load into the dryer to start a second in the washer.

A family member lives overseas and has a 220V heat pump clothes dryer. A light load takes 90+ minutes to dry (after exiting a washer with a high RPM spin cycle). I know, I've used it. A larger load can take as long as 2 hours.

I doubt the claim of a two hour wash and dry cycle for the GE unless the wash cycle is 15 minutes or the load referred to is very small.

If the temperature is 25F, the weather is usually pretty dry. There could be water on the unit from rain that fell before temps dropped. Wouldn't the defrost cycle run for a bit, melt and dry out the unit, and then keep chugging?

That's not what the issue is.

Your info seems a little out of date Elmer. I have 3 of the GE machines so you can doubt all you want. The drum is slightly bigger than the average drum at 4.7cu and a full load of sheet or clothes will wash and dry in 2 hours...110 plug, no vent, no gas. You can load the machine and leave the house or go to sleep and wake up to dry clothes. You can't do that will the old technology... so stay home on laundry day if you like.

Your relative does not have the break through GE machine. There is nothing like it on the market. It is new technology introduced at last years consumer electronics show.

Haha, well, I don't remember the brand but I know it's Japanese. Japanese companies were the original innovative developers of heat pump products and remain so today.

GE, as you may or may not know, is a Chinese owned company and many of its products are made in China. The branded consumer products of the parent, Haier, have a terrible reputation in the US. Two good reasons to avoid GE.

I have friends who are afraid of anything new, too. No worries.

Thanks everyone for helpful advice! We ended up going with the Mitsubishi hyper heat model, no backup heat. Crews are installing it now. If we made a mistake, we will use the nice oil-filled space heaters we bought to get us through this week.

Yes, you gotta get the Mitsubishi hyper heat model - that will still heat your home when it gets pretty cold.... efficiency goes way down when temps are near zero,

We've had a 12K hyperheat heat pump in NE Seattle for more than a decade - we turn it on in the AM and leave it on all day (unless we leave the house) . It usually heats up the place within an hour or so.

Really works best in a well insulated space, since heat delivery is slowish - if you are in a drafty home it may struggle to keep up. So insulate and go with multi-pane windows.

also I dont believe in multi zone, get one head unit for each indoor unit, if you can - you'll have more redundancy, and generating capacity as well as shorter coolant runs. This is how people in Japan do it. Only reason to have multizone is if you think you'll only use one head unit at a time.

just my $.02 worth - hope your project goes well

-M

I have a multi-zone with 4 head spread over 2 floors. One bedroom downstairs and one bedroom upstairs. As we know, heat rises. If you spend the night running 1 or 2 heads downstairs then lots of heat will go upstairs even without that upstairs unit running.

Thats my only problem with the multizone. I cannot cool the upstairs bedroom to a more comfortable temperature to sleep if the heat is on in the chilly downstairs bedroom. So, I will be buying a separate compressor and attaching one of the bedrooms to it. Its extravagant but the installer told me I can piggyback the 220v from the other unit and just place the unit right next to it... after inspection.

Thanks Mattrophy and Paul F. We got the Mitsubishi installed a few days before Christmas, and so far it's doing well. This weekend will be the real test--overnight lows of 20F, which counts as a serious cold snap here. FWIW we have a ducted system, not a multi-head ductless.

My only complaint so far is the sounds. Some of this is having a compressor outside a living area window, instead of isolated inside the garage, like our furnace. But the heat pump outdoor unit makes a very different sound from the old AC unit. Deep motor rumble that we can hear throughout the house. I assume we will get used to it, but we're also talking to the installers about sound dampeners on the bolts and other things we can do. I swear I can feel the vibrations physically (DH insists I'm imagining this, he may be right).

Wow, the outdoor units I have to put my head near them to make sure they are running they are so silent, no vibration whatsoever. I installed mini splits in my rentals so I have 4 compressors total and the installer put one directly below a bedroom window outside, the window swings open about 15" above it and there is the slightest white noise coming from it during the dead of night.

I guess that's good news. I've heard from everyone how quiet they are, and this one is just not. Hopefully that means something is a bit wrong with our install and this can be improved. When I think of the whole neighborhood having machines generating this sound, the future seems depressing.

mcarroll16, I'm in NE Seattle. I'm in the same boat as far as noise & vibration is concerned. I got a Mitsubishi Hyper Heat installed in Spring 2022. I had the installer put anti-vibration pads on it. It helped a bit, but I can still feel it. The rumbling and the buzzing though! I can hear that thing from every room in my house and it wakes me from sleep even with a white noise machine cranked. Granted, my house is old and drafty with single-pane windows, but I certainly wouldn't call the unit "whisper quiet", as advertised. It doesn't help that it was installed in the narrow side yard between mine and my neighbor's house. It's effectively an echo chamber. My neighbor can hear all the noise too. I feel awful about that. Frustratingly, when technicians have come to check it out, they say the noise is normal and within the dB limits. I'm now considering a compressor blanket and a fence with insulation, and if that doesn't help, moving the unit so at least it's not bugging the neighbor. It's been a total PIA and really disappointing after spending $$$$ to have it installed. I hope you have better luck with your unit.

Btw, during last weekend's super low temps, after 8+ hours of the heat cranked to 75, we reached a balmy 63 degrees inside. Like you, no backup heat. Luckily, I'm accustomed to keeping the house on the cool side anyway.

We have the SUZ-KA36NAHZ. But I strongly suspect that it's an installation issue. The sound inside is faint. The vibrations are what's driving me crazy. I think the refrigerant lines are tranferring vibrations where they are attached to floor joists. I noticed it from the beginning, DH and oldest daughter not until this cold snap. The other night my daughter jumped up from her dining chair, because the vibrations bothered her so much. When the motor runs hard it makes the fridge vibrate too. I notice that the sound sound in our upstairs rooms is about the same, but the vibration is absent.

@kmuelly, I'm surprised by your unit's poor heating performance this past weekend. Bellevue is usually a couple of degrees warmer than Seattle, but not that much. I turned our unit to 69 on Thursday afternoon, to prepare for the cold weekend. Our temp dropped to 67 in the early morning hours Friday and Saturday, but never got lower than that, and managed to stay at 69 through most of the daytime hours. I have no complaints about the heating performance. (For other Houzzers, Seattle area was low teens overnight this past week, low 20s daytime.)

Today was the first day we turned on AC. In cooling mode the heat pump is amazing! I cannot hear it indoors. Standing 10 feet away outdoors, it's audible but extremely tolerable. Much much better than our old AC unit. I think I would keep it running when seated on the patio, where we used to turn the AC unit off when we hosted outdoor events.

I've been tracking the noise levels with a decible meter iPhone app this spring. I'm fairly convinced that some of the noise is an install error. and that heat pump vibrations are being amplified by our house framing. The heat pump is on the NW corner of our house. Our master bedroom is on the second story SW side. I can hear the heat pump clearly in the bedroom. Unless I open a window, and then ambient outdoor noise completely drowns out the heat pump sound.

Not sure what we are going to do about this yet. For other Houzzers considering a heat pump, I don't think our experience should be a reason not to get one, or even a knock against this Mitsubishi model. Just hire really experienced installers.