Supplemental heat for a wood stove...opinions on mini split heat pumps?

[Dalmatian90]

Long story short:
Looking at a Mitsubishi ductless HyperHeat system for a 650 s.f. soon-to-be well insulated ranch house in Connecticut.

It will "officially" be the central heating system. Reality is I've heated exclusively with wood for 10+ years except for the extreme ends of the heating season when I use electric space heaters.

Anyone have experience with one of these is a moderately cold climate? The Mitsubishi HyperHeat system is rated for -13F which I've only see maybe every four or five years here. Plus I reckon the A/C will be more efficient than my window unit.

Short story long:
So I'm in the process of dumping a ton of money into my house...will count myself lucky if I end up south of $45,000 by the time I'm done.

Which will result in refinancing the mortgage once I'm done to roll the loans into it.

Which means the insurance company and bank will have a kaniption that my only heating system is a wood stove built I think before UL started listing stoves. (Hoping I can find an insurer who won't mind the old stove, but it being the only heat source WILL be a problem.)

House will be well insulated when we're done -- the 4:1 roof is coming off, a 6:1 roof is going on. (Thankfully I have another section for my chimney...more draft!). Siding and sheathing is coming off, sills and studs fixed as necessary, new insulation as necessary, followed by new sheathing, tyvek, and vinyl.

Plus a bathroom down to new floors and studs, and the beginnings of a kitchen remodel (vaulting the ceiling over part of the living room & kitchen to make the 650 s.f. seem bigger).

I don't want a furnace in the basement because it floods occasionally, and one flood too many finally took out my old oil burner many years ago. There are some drains that collapsed after 40+ years which I can rebuild to reduce the reliance on sump pumps, but it was too darn wet to think about digging this year.

Propane wall heaters seem to take up a lot of my limited wall space, the cheap ones have horrible efficiency, and the efficient ones...well by the time I get that installed plus a propane tank I think I'm around the cost of a mini-split.

I already have a concrete pad that can be re-used to mount the A/C-heat pump unit on, and I think I have a good location for the indoor unit which will circulate the air well in my house and be out of my way wall space wise.

 

[cre73]

We have installed 2 mini-splits in the last couple years. Mine have worked well for shoulder season. Mine are not good down to that low of temperature. I think mine only work down to about 10-15F. Between the two of them I have about 3k invested and installed them myself. Hope they hold up well.

 

[ChoppyChoppy]

I've never had a roof pitch like that. Here's it's like 4-12, 6-12"

 

[Mustang71]

I have installed many of them and we have the best luck with Mitsubishi. The heat cool units work very well. Make sure you keep it up off the ground because the snow can block it and there goes ur heat.

 

[NSMaple1]

I would not hesitate to go with a mini-split. Some new homes around here are even being built with those as the sole heating source.

Mitsu, Fujitsu and Daikin are likely what I would call the big 3, and what I would with. I haven't got one but can see one in my future - I yanked out all our oil-fired stuff 6 years ago and now have wood with an electric boiler as backup. If (when) I get to the point of that electric boiler being needed for anything more than very infrequent backup, I will be evaluating alternatives and a split will be the first consideration in the evaluating. Plus it gives cheap a/c in the summer.

 

[OnTheRoad]

I'm not experienced in mini-splits but they make sense to me. However I do have experience with a heat pump. 10 years ago I had one installed at the house and here in Missouri, it isn't of much use most of the year. When the outside temp is 45 or better, it works just fine. However, the natural temp in the house in that weather is close to my comfort level without additional heat. When the outside temp drops below 40 the heat pump blows cool air and regardless of the temperature in the house, it feels cold. There are maybe a dozen days a year where the heat pump could heat the house but the days on either side of those days it might not do the job. It's more trouble than it's worth to switch back and forth from gas to heat pump during that time.

Since the heat pump was installed, it's almost never been used in heat mode. That extra $500 was a complete waste.

Your situation is very different but don't expect much from the heat pump.

 

[Mustang71]

Well here in the buffalo N.Y. area I install a lot of those mini splits. They have come a long way in the heat pump technology. We put them in for heat now not just ac and they work very well. I'm not saying heat all winter with it but a good amount of it. And as an add on to a wood stove In a small comfortable house it would work great.

The Mitsubishi has a heating element to melt the snow away from the condenser the LG does not. We have had a lot of issues with the LG.

There are many customers who do use them for heat all winter around here and they work. We are mostly between 10 and 30 in the winter.

 

[Dalmatian90]

Thanks guys.

Reading up on them, it's clear the technology (on the heating side) has dramatically improved in the last ten years...which makes a lot of internet stuff already obsolete.

Waiting for the final quote, going to take a two-head 23,000 but system which I know is a going to add a bit more than I expected...but also needs a 40A circuit so as soon as he said that I knew I'm also upgrading to 200A service :/

 

[Mustang71]

Upgrading from what service? That's about as much power needed for a 4 ton condenser unit for a large house. I'm surprised it would need that much power. Is that the maximum breaker size that's listed for the unit? I would think it would be more like 20 amps and it's not going to draw anywhere near 40 amps when it's running. I'd think a 150 amp service would be enough unless you have all electric appliances or are running a pretty nice garage with a lift and welder and such.

 

[Dalmatian90]

It's all electric appliances, plus garage, and is already 200A through the meter.

So you're only talking about the cost of the 20' of cable from the meter to the panel if the electrician 20 years ago didn't oversize it when the fuse box was replaced with a 100A panel...which knowing him he very well may have. (I can't find the gauge on the insulation jacket that I can read)...other than that the labor is going to be the same. Plus I've never heard of a 150A service in this area; not sure if it's code or local traditions.

 

[ChoppyChoppy]

My folks in Maine had one put in about a month ago. They had to upgrade the power, had 100 amp service which fed the house, shop, and 2 garages. The panel 8n the house was full too. Cost $350 for a sparky put in a bigger panel (I thought that was really cheap)

100 amp is common here too, that's what I have. All my stuff is gas though.

 

[Mustang71]

Hmm odd I see 100 150 and 200 all over the place around here. I have 200 amp service and am happy with it. Sounds like upgrading won't be to bad to do.

 

[ChoppyChoppy]

Hmm odd I see 100 150 and 200 all over the place around here. I have 200 amp service and am happy with it. Sounds like upgrading won't be to bad to do.

Most houses here don't have much of an electrical load. Kitchen stove, water heater and dryer is about it for power hungry items, and lots of houses those are gas.
I'd imagine in areas where A/C is common 100 amp wouldn't be enough.

 

[67L36Driver]

It gets warm here on the backside of Missouri.

We put in a 200 amp service so I could run my arc welder, air compressor and central air without tripping breakers.

 

[Mustang71]

I have all electric stuff besides the furnace along with welders and a 60 gallon compressor. The compressor doesn't draw much for power. My house is 1700sqft my ac is on a 30 amp breaker but I could have done a 20 amp also. 100 amp is very common around here on houses built pre 1980s the main problem is the panel is to small to add circuits so people upgrade.

Most people have gas everything in the city and suburbs but where I live there is no natural gas so it's all electric or propane.

 

[OnTheRoad]

For you HVAC experts, I'm curious what has made the current heat pumps so much better than the 10 year old models. Boyles law doesn't care what year your heat pump was made. There is only so much heat available in 35* outside air. When it's 20* outside, what is the outlet temp of the new super duper heat pump at the register and at what cfm? I'm skeptical about these systems because there just isn't much heat in 20* air. Heat pumps work great where the low temps are in the low 40s but are worthless in cold climates. I pity anybody who is counting on a heat pump when it's -10 with the wind screaming as we see in winter here. What would the temp at the register be when the ambient temp is -10 at 1400cfm with a typical 4 ton system?

 

[Mustang71]

I'm not sure about regular split systems with heat pumps because we never put those in.

The mini splits are computer controlled they control the outdoor fan the refrigerant flow and adjust based on temperatures. You can plug into them and get a full read out of the info. I've never seen them working in 10 degrees because I don't hang out at people's houses all the time but people say they work.

They manage to get 21 seer out of those units too where a regular condenser is 13 to 14 in the north east.

 

[Mustang71]

I'm also in the western NY area it doesn't get to -10* here usually 20s and rarely below 10*.

 

[al-k]

we ended up getting a lennox. i know its not the best but it was about 1k cheaper. we have a 2 zone 9k in the bed room and 15k in the main living area witch is 30'x 26' with 18' valeted ceiling. have only used it for cooling so far and it works great. light bill is about 40$ more a month and it cost us 8k to have it installed with a 12 year warranty. i really like that i don't have to lug that window ac unit up and down stair any more. had to put a 25 amp disconnect and a 20 amp service gfi out side. hope this helps some

 

[Mustang71]

I don't have anything good or bad to say about the Lennox. I don't know who makes them but Lennox just puts the name on it. Same with Lennox boilers. The boilers are Dunkirk boilers but a different color and cheaper. If they put their name on it it's probably not a bad product.