Home Heat Pump for a mild climate

[uglymoney]

Great question. I'd like to know the same thing, or if there is an internet calculator somewhere to plug numbers into.

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[Core Shot]

I don’t know the number.

But yes. At some temperature a ductless split becomes resistance heat.


Nat gas isn’t evil in a high efficiency furnace.
Odds are there’s a nat gas peaker generating electricity to send to your heat pump and Tesla.

[NBABUCKS1]

How are you measuring your current COP?

Gree makes an easy to read chart that shows the BTU's produced at outside temp with COP



For reference a 1500W resistive space heater makes 5118 BTU's. At no point is it more efficient to run a space heater - however I would get more BTU's below -15. Oh also apprently I lied in my original post and I'm gettin 2.14x the BTU's

Also here is NEEP's indpendent testing of my model - they have a whole database.

https://ashp.neep.org/#!/product/25405/7/25000///0

[NBABUCKS1]

Nat gas isn’t evil in a high efficiency furnace.
Odds are there’s a nat gas peaker generating electricity to send to your heat pump and Tesla.

And that's fine. I still wouldn't own a heat pump w/o some kind of backup power - wood stove, nat gas/propane furnace (would need generator interconnect to run furnace in power outage...)

The whole 'coal/nat gas/fossil fuel is powering your EV' argument is silly. Of course they are - and that's great. It's more efficient to have one large generator making power than millions of tiny less efficient ones running around (ICE engines for cars)....I/we're getting off topic....

[Shorty_J]

Gree makes an easy to read chart that shows the BTU's produced at outside temp with COP



For reference a 1500W resistive space heater makes 5118 BTU's. At no point is it more efficient to run a space heater - however I would get more BTU's below -15. Oh also apprently I lied in my original post and I'm gettin 2.14x the BTU's

Also here is NEEP's indpendent testing of my model - they have a whole database.

https://ashp.neep.org/#!/product/25405/7/25000///0

Thanks for that link... I'll explore a little more on that site.

Looks like you have a 38 seer unit?!?!? Wow! I think mine is 17 or something... I doubt mine is getting similar performance to yours.

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[uglymoney]

I don’t know the number.

But yes. At some temperature a ductless split becomes resistance heat.


Nat gas isn’t evil in a high efficiency furnace.
Odds are there’s a nat gas peaker generating electricity to send to your heat pump and Tesla.

Meh.

Iowa is over 60% wind generated electricity now. My gas furnace sucks at turning that into heat.

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[Shorty_J]

Can't seem to find any other models on that site.

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[Shorty_J]

Meh.

Iowa is over 60% wind generated electricity now. My gas furnace sucks at turning that into heat.

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Where I live almost all electricity is gas powered... and probably not 97% by the time you get the power to my house.

I'm all for making the heat pump do more work but without the data I'm not willing to not let my new efficient furnace work when I don't know how the heat pump is performing in the cold.

I have already had at least 1 incidence that I know of where I was in the heat pump operating range and the furnace was running instead of the heat pump... I.e. it needed a defrost cycle even then to clear it so it could work.

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[uglymoney]

Absolutely.


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[Core Shot]

Meh.

Iowa is over 60% wind generated electricity now. My gas furnace sucks at turning that into heat.

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Jfc. I had to google that shit.

It’s over half. Wow.

And how do they store the energy for when the wind ain’t blowin?

[uglymoney]

Great point, you win. Back to heat pumps please.

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[NBABUCKS1]

Absolutely stupid how well these things work. I spent $1k on the heat pump and $3k on a wood stove and stove pipe. I haven't even hooked up the wood stove yet (long story) and the heat pump is doing everything and I've had it down to -5 F. Really wish I hadn't spent that money! Helps that my place I built is super tiny and well insulated. Line set is a disaster because I installed it in 30 degree weather and didn't want to kink the lines bending them so ignore that.

Put it about 4 feet up on very non approved mounting base. I didn't mount it to the house because everyone complains about noise when attached to structure. This isolates it.

Edit sorry about the double image but i can't remove the sideways one.

[NBABUCKS1]

also this is a super cool website that shows real time (idk how valid) where your energy is coming from

https://app.electricitymaps.com/map

[Nobody Famous]

Absolutely stupid how well these things work. I spent $1k on the heat pump and $3k on a wood stove and stove pipe. I haven't even hooked up the wood stove yet (long story) and the heat pump is doing everything and I've had it down to -5 F. Really wish I hadn't spent that money! Helps that my place I built is super tiny and well insulated. Line set is a disaster because I installed it in 30 degree weather and didn't want to kink the lines bending them so ignore that.

Put it about 4 feet up on very non approved mounting base. I didn't mount it to the house because everyone complains about noise when attached to structure. This isolates it.

Wow, nice job for $1k. If that cost included the inside blower unit I'd say you did great, exceptional.

The latest refinements and updates in mini splits are impressive. Gree and Fujitsu are pushing the envelope on cold climate performance units. The latest are spec-ed to work down to -15F and -18F. Think about that, a mechanical device can efficiently extract heat from outside air when the air temp is -15F.

This level of performance was not readily available just five years ago, or even two years ago. Performance on the traditional whole-house heat pump systems have been a few years behind the mini splits, and when the traditional systems catch up to where the current mini split technologies are today it will really be something to see, game changing.

I'm hoping when that time comes in a few short years the manufacturers will have perfected the designs for heat pump systems to work interchangeably with radiant heating systems. That's when I install radiant. Imagine that, it's 0F outside and your floors are a comfy 72F heated from an air sourced device sitting a few feet outside your home.

P.S: Install, don't sell the stove. It's a backup. You hit it out of the park on the installation but should you ever have a breakdown in the middle of cold season you'll find few if any HVAC contractors who will troubleshoot or service DIY installs. Warranty coverage is usually denied if the work is DIY. And if a few years elapse there's no guarantee you'll might find the same model or any model that is usable, directly interchangeable, with your inside blower unit and line set/plumbing.

[Dromond]

Well, two and a half years after I started this thread, I got a heat pump. We replaced our 15 year old gas furnace with a 2.5 ton Fujitsu ducted heat pump. The air handler went right in the place of the old furnace, and there was a good spot for the outdoor unit a short distance away.

I got the higher end Halcyon unit this has no loss on efficiency down to -5, eliminating the need for any backup heat source. As a bonus the outdoor unit is smaller and quieter. It’s so quiet that I can barely hear it running just a few feet away.

I decided to replace the furnace because it needed a few thousand dollars of preventative maintenance, and I felt better about putting that towards a newer electric system that could also provide cooling in the summer. So far I’m really happy with it. I hemmed and hawed over how large of a system to get, but this one kept the house at 68 when it was 15 outside which is about as cold as it gets here. The only brief time it couldn’t keep it at 68 was actually one night where snow was melting outside and so it was 32 and extremely humid. This seemed to cause the unit to ice up faster and go into its periodic defrost mode more often. The result was that it dropped to 66 inside for a couple of hours because it can’t output heat during the defrost cycle. No big deal.

Overall the temperature is much more even in the house with a constant flow of warm air coming out of the vents. This variable speed unit is better in that respect than our old on/off one speed blast of hot air gas furnace. We keep it at 68 and during the day at 66 at night which it handles no problem.

One tip is to get multiple quotes when looking for an installer. I took a lot of time and got 5. The size of unit and prices quoted were all over the place. One was more than double what I paid for a similar unit from Mitsubishi, in part I think because it was from a well known white glove type installer that is well known and spends a lot on advertising. I went with a smaller company where the owner does the installs because he was more straightforward to work with and just wanted to do the job efficiently for a reasonable price and move on. The install was quick and easily fit into one day. I did have the electrician come earlier to do his work because I also wanted him to install and electric car charger in the same visit, which worked out great.

All in all I’m pretty pumped about this thing (sorry) and am looking forward to a cooler house during heat waves as well as steeply dropping gas usage.

[Nobody Famous]

Insightful article on Heat Pump usage in the extreme cold of Winter in Maine. Seems like the entire state is lining up to install a heat pump, 116k signups in a state with 600k occupied housing units.

Skip over the mentions of the national trade groups several individuals report their experiences, even one heating oil delivery business owner weighs in, he says he only used his for cooling.

These are all the latest 'efficient at extreme low temp' models.

https://archive.ph/yVCH2

P.S: Look at the installation in the 3rd picture, the base looks way off-plumb to my eye, surprised this passes any basic installation checklist or code inspection.

[teletech]

During the last cold snap mine stopped working at around -10ish. It just in an addition I added so that area was freezing but the furnace was working in rest of house. It that was my primary heat my house would have frozen. They are great 95% of the time though. I live in Maine

[m5d5cb]

https://www.premiumhomesource.com/pr...-hp-wm-230c25#

Anyone ever done the DIY route? Looks fairly simple…..

I DIYed a Mitsubishi 18k BTU GL series heat pump for my garage. It was about $2500 in parts/materials but I see prices have increased. Easy wiring because its on the same wall as my panel – 220V 15A breaker. It's only about 8A steady state max output.
I'm not sure what it would cost to have a pro do the entire install but I would guesstimate $6000?

I regrettably missed out on a H2i hyper heat, but I think this is still good for 100% heating at 10F and operates down to -4F. Vs H2i with 100% at -5F and still operating at -18F as noted above (amazing). I didn't know H2i was an option at the time but we only saw down to 15F this year anyway.

It works VERY well. I thought I wanted it for the AC but the heat is way more valuable. It will heat my 700sqft garage up from 50F to 70F in about an hour when it is 20-30F outside (those numbers are not scientific). Whisper quiet inside and out. Just a gentle, 105F (If I recall correctly) breeze.
My electric bill may have gone up $15/mo with me keeping it always set to 50F and having it 'at temp' for projects several times a month.

It's been fantastic for working on cars or woodworking in the garage.

For full DIY I recommend a Mr Cool system (still Mitsubishi), unless you have a vacuum pump and want to deal with flares.

Mitsubishi also has the ceiling mount cassettes that may be a much slicker looking in-home addition or upgrade.
A friend of mine went with a ceiling unit (I think maybe a different brand) after seeing it.
Another friend saw mine and DIY'd a Pioneer system with 3 units in his cabin and it works great and is way less expensive than Mitsubishi for a part time place.
Yet a third friend says he is going to have a Mitsubishi system installed in their winter place (but talk is cheap).

[dmcd]

Saw this thread and I'm testing some new heat pumps right now for work. There are wall mount heat pumps without outdoor units that are becoming more prevalent and are far easier for a DIY or inexpensive install. A few companies (Ephoca, Olimpia) have units on the market right now. They're the entire system in a single package with just air intake and exhaust holes that need to get punched through the wall. We're testing one at my work right now and I've been really impressed by it. Obviously this isn't for an entire house, but if you've got a large open space or a single room (garage, living room, ADU) you want to heat/cool these are pretty interesting, with no ducts and no outdoor unit to run lines from and they just run off 110V so no electrical work either. Ephoca makes one version that has an ERV built in as well for fresh air and they all have resistive heating for when it get's really cold.

Pretty cool tech that they can fit the entire system into a 40"x22"x6.5" box and all it needs is two 8" vents to outside.