Mini-split heatpumps in winter?

[SmokeyDP]

I have 2 LG split systems, each with 3 zones for a total of 6 zones in my house. The one setup is 3.5 years old and the other was just installed this month and has heat built in.

At what point are these no longer efficient to run to heat your house? I have steam radiators so this was more just for my curiosity than anything. I heard the older ones wouldn't work when it was below freezing but that the new ones are designed to work in these conditions.

 

[SkipsShop]

Depends on what seer it is.

 

[JerseyHarold]

Some manufacturers claim that their systems work to about 20 degrees, but the colder you get the more the efficiency drops off. I wouldn't use one below about 28 degrees.

 

[HVAC Phil]

I have my heat pump in my house set to not come on at 25*, then to fire 1st stage of gas heat. I would use the heat pump in the house on the mini-split till around 25-30*, the use the boiler to take over from there.

 

[Jackfre]

I do not know the performance curves of the LG. I'm assuming both units are inverters. LG should be able to provide the info you seek. With Fujitsu ( which I represent) the curves are published for power input in kwhs vs btuh output. I have friends in VT and NH who run their units down to 20f and then bring on the oil. Savings $-$ of over 50%.

The thing is, you will decide your balance point based upon how you are living in the house, ms location and ultimately how comfortable you are in the house. Every system has a personality and you get to find out what yours is.

Contact LG, find out who the local manuf rep is and with your models and ser #'s available, find out what the output curves are. Keep us posted. I'd like to know hownyou make out

 

[SmokeyDP]

Thanks for the responses!

I don't feel like chasing down the information from LG, I was more looking for some general information found in this thread. Since only half the house has the heat pumps, it's kind of a moot point since I have to run the steam system for the other half since it's all one zone.

 

[HoosierBuddy]

I've never heard of a hybrid minisplit...but one point is you would certainly NEVER want to run your resistance heat strips if you have another viable option. Once a heat pump reverts to the electric resistance strips, it's going to use about 3 times as much electricity.

Phil

 

[HVAC Phil]

I've never heard of a hybrid minisplit...but one point is you would certainly NEVER want to run your resistance heat strips if you have another viable option. Once a heat pump reverts to the electric resistance strips, it's going to use about 3 times as much electricity.

Phil

Don't know if this was meant towards me or not, but i don't have a mini-split. I have a gas 2 stage var spd furnace with a heat pump. I was just giving him of an idea when the heatpump will no longer be efficient.

 

[HoosierBuddy]

Don't know if this was meant towards me or not, but i don't have a mini-split. I have a gas 2 stage var spd furnace with a heat pump. I was just giving him of an idea when the heatpump will no longer be efficient.

I was not referring to any of the other posts.

Phil

 

[NoSloCoupes]

Wow, i've been looking into a mini split with a/c and heat for the shop. No idea they shouldn't be ran when the temp is that low in the winter....i'd be in the shop when its below the 20's.

 

[hydramatic]

whats wrong with NG..the new Rheem is 80% efficient..the newer heatpumps have NG as a backup anyway..or 8000watt electric...I don`t like a compressor running winter and summer..NG is clean and cheep..compaired to a Killowatt...

 

[itsy]

I've never heard of a hybrid minisplit...but one point is you would certainly NEVER want to run your resistance heat strips if you have another viable option. Once a heat pump reverts to the electric resistance strips, it's going to use about 3 times as much electricity.

Phil

http://www.fujitsugeneral.com/hfi.htm

I believe they are new this year and you have to be certified through Fujitsu to buy/install them.

 

[thammel]

A hybrid mini-split system should be no big deal to set up and makes a ton of sense. I have a ceiling suspended Reznor propane heater. I'm also planning to purchase a mini-split heat pump. No matter what they say, the efficiency of the heat pump will start to drop dramatically below about 35F. So my plan is to buy a Honeywell 8320U t-stat (I have 2 of these in my house) and an external temperature sensor and set it so the Reznor turns on when the outside temp is about 35-40F. This should take the load off the mini split so it will not be needed (especially if I set the mini split t-stat about 2F-4F below the Honeywell tstat for the Reznor).

My lower level house system needs replacing. It's a propane furnace with an AC. My plan is to replace with a heat pump and propane furnace hybrid system. In the long run this will be cheaper.

Tom

 

[sneezer41]

The new Mitsu's and I think other high end ones will run down to -13 with 100 percent btu's down to 5 degrees[just looked it up]

 

[WVBrady]

The new Mitsu's and I think other high end ones will run down to -13 with 100 percent btu's down to 5 degrees[just looked it up]

Can you provide a link or reference? I looked for energy star rated mini-splits and couldn't find any Mitsubishi units that weren't dual or more units. I would like to have just one indoor unit.

 

[SmokeyDP]

I was on LG's site earlier and the unit says it runs down to 5F, but no mention of how efficient it is. I did see however, that now they have a 4 zone unit too.

 

[sneezer41]

http://www.acdirect.com/xcart/product.php?productid=2853

26 seer, -13F

No they don't give them away

 

[sneezer41]

I followed the fujitsu link, it appears to be like the mitsu city multi system, nothing new really. I considered the fujitsu halcyon units this time around but had used the mitsu before so stuck with them.

 

[NoSloCoupes]

I'm wondering how one of these units would do in the winter in my 32x30 with 14' ceilings....i'm guessing ceiling fans would be a must to?

 

[rickairmedic]

I notice that most of the people in this thread asking about " heat pump units " have no location in their profiles . I will say if you live in Fla then a heat pump mini split will be a great addition to your home if you live in Maine not so much .


Rick

 

[Jackfre]

I notice that most of the people in this thread asking about " heat pump units " have no location in their profiles . I will say if you live in Fla then a heat pump mini split will be a great addition to your home if you live in Maine not so much .


Rick

Rick, I sell them in Maine. What I tell the Mainers is that the way to make oil heat more efficient is to burn less of it. Install the MSHP and run the bejeepers out of it until you hit your balance point. That is typically about Dec1. That way the single stage, over-sized boiler will have a load against it and operate fairly efficiently. I have customers who have had a dollar to dollar reduction of up to 60% using the mshp in conjunction with their boilers. The one fellow is a contractor who puts a sub-meter on each of his units sold. Most of his business is now coming from customers who can read the actual consumption on the mshp and compare bills. They then tell friends. So, don't change your still operating system...add the mshp. We don't need a lot of cooling up here. We do need dehu though.

I agree that in any of the climate control threads that a location should be included. How's the house coming?

 

[redsky49]

There simply is no blanket answer for this question. It all..."depends".

It depends on location, climate, home construction, local utility rates, occupant lifestyle, age and type of HVAC equipment, etc., etc.

To arrive at the correct answer(s), you have to crunch the numbers.

My relatives in Minnesota use air-to-air, as well as ground-coupled heat pumps. Go figure

Sometimes a utility company will help with this decision, but they frequently have a vested interest.

You need to know your utility rates, heating/cooling requirements, and a crystal ball to predict the future. Rebates make a big difference to this calculation, and they change all the time. Best thing is to pick up your calculator and pencil and work out the details for your personal requirements. Start with the cost of a btuh.

As always, offered only as opinion

Red

 

[honcho]

Where do you look for competent minisplit dealers / installers for a residential installations? It's hard enough to find a honest HVAC company that doesn't gouge right and left. The companies around here don't want to sell residential minisplits for some reason. Maybe it's not profitable enough for them or it's just something that's a limited niche market. I know someone deals with them because I see them in all sorts of commercial settings but don't personally know anyone with one in a residence.

 

[Jackfre]

Where do you look for competent minisplit dealers / installers for a residential installations? It's hard enough to find a honest HVAC company that doesn't gouge right and left. The companies around here don't want to sell residential minisplits for some reason. Maybe it's not profitable enough for them or it's just something that's a limited niche market. I know someone deals with them because I see them in all sorts of commercial settings but don't personally know anyone with one in a residence.

At Fujitsu we have a "dealer locator". Go to www.fujitsugeneral.com and follow the yellow brick road by entering your zip code. It will list dealers in your area. You will see similar information from many manuf.