Mini Split Effectiveness - A/C and Heat Options

[Kaoskido]

I am wondering of those who have mini split units do you have one that does heat as well?

I live in Minnesota and I have been pondering doing something for my garage as I like to tinker but when it's blazing hot/humid or frigid cold it keeps me out of the garage.

I have an attached 23x23 garage but does face to the west so we get lots of wind. The garage is fully sheet rocked and insulated.

Would a mini split with heat be an option? If not what could be an alternative?

 

[fitter30]

Look at a PTAC heat pump with electric strip heat. Minis heat pumps do not come with strip heat.

 

[dcg9381]

There are heat pump mini-splits, generally cost not much more, maybe 10-15%. It's not uncommon for them to have heat functions. Perhaps more with heat that without.

As indicated above, they do not have "aux heat" - so once the heat pump gets inefficient, that's it... Unlike the electric heat in your heat pump at home. (if you have one)

There are some units designed to be efficient down to "very cold" and still produce heat.
But if your area, you'll want to check out the performance graph. Heat pumps do lose performance as temperatures get really cold out..

 

[jjrbus]

My Daikins heat and cool. Cool really well but I am in Florida so will not comment on heating LOL

 

[MattT]

Would a mini split with heat be an option? If not what could be an alternative?

Probably not a good option for primary heat in your climate. You could probably do it with a "hyper heat" mini split but it'd be expensive and way oversized for cooling.

What heating fuel options do you have?

 

[finn]

We put Mitsubishi Hyper Heat units in my wife’s basement exercise / tv room and another in our guest house. They heat ok down to about 13 degrees below zero, but are pretty ineffective at -16, based on our experience last winter.

The units were installed about a year and a half ago to replace electric resistance baseboard heaters.

I wouldn’t recommend them as a sole heat source in much of northern Minnesota, but they are fine for our area, where the temperature is moderated to some extent by Lake Superior, as long as there is another heat source, like propane or resistance to get us through the few really cold days.

 

[Raisedonadeere]

Hyper heats work well well below zero. Mine has only seen -1 or so but you can review the specs on th one you are looking. The morning we hit zero I was amazed the air exiting the unit still felt hot. I was used to my central units trailing off as it got colder to the point that the air felt cool.

Yes mini splits hyper heats are excellent heaters for most if not all season. I have my old resistance heaters from the central as back up with emergency propane heaters which could use as supplement. Never needed it last winter. I am very pleased with the energy cost savings as well.

 

[PurdueSD]

I have a Bryant multi head mini split Heat/ cooling my shop. 4.5 tons of cooling if my memory is right.

I am further south than you so, your cold is a little lower than ours. I chose mini splits for the first time in my new shop. They have performed amazingly well and are super inexpensive to operate so far. Mine are rated down to 0 degrees but i only have seen a couple weeks in the single digits since they've been installed.

I keep my shop 64 (lowest set point) in the winter and 78 in the summer. Im heating cooling over 2850 sq feet with 14' ceilings. Our electric rates are some of the highest in the midwest and so far, my bill averages out to around $50-70 per month.

Honestly my only complaints so far were about not being able to have a lower set point in th winter. But 64 is perfect to me after using them. 2 heads evenly distribute heat to the large open 42x60 portion of my shop.

Drink the kool aid would be my suggestion. The lack of humidity having AC in the summers is a game changer.

 

[HoosierBuddy]

Sort of OT...but at work we use a Mitsubishi Mini Split to cool the server room.

It has both heat and cooling capability...and sometimes in the very coldest part of winter they actually use it to heat.

The "outdoor" unit is outside the wall of the server room where it backs up to a heated warehouse...which is kept at about 55 degrees in the winter with NG hanging unit heaters....so it works pretty well as the "outdoor" unit never gets below about 55 degrees..... Not likely installed according to Hoyle.

Phil

 

[Lonnies Performance]

I have Daikin mini-splits which also heat. They are rather efficient down to about 30 deg. Below that the cost to operate increases with the temp drop as the output falls off.

My 30K btu unit is 36K at 43 deg, 26K at 32 deg, 20K at 14 deg, 16K at 5 deg & below zero it is about 10K. When you need it the most, it puts out the least, but it is economical to use in normal ranges. When you approach the teens outside, something with strip heat is a better option.

I have 4 of these in my garage & 2 keeps it in the mid 70's in the summer, but all 4 couldn't keep it in the mid 50's when it was single digits outside.

 

[Notgrownup]

Most of my family in Canada have gone to mini splits with heat...they work great... PTAC units are less efficient...most of them have a wood or propane or baseboards if it gets down really cold .

 

[HotrodHR]

I have a Mr Cool 18k BTU minisplit and it cools my 24x24 shop during 95 plus humid days in north Alabama like an champ. Quiet, cold and efficient. If it heats half as good as it cools I'll be happy. This will be my first winter using it so we'll see... nothing like MN though.

 

[Kaoskido]

I didn't realize there were so many replies to this thread - I am not getting any of the emails for them....

So there are times where we are well below zero for weeks at a time. So I do need something that would like the one user said to keep the low point in the 60's during the winter.

My only options are electric or I do have natural gas but it's no where near my garage and then I would need venting, etc.

Would it be better to have a dedicated electric heater for winter and then a mini-split just for cooling vs. trying to have a mini-split that does both ?

 

[MattT]

Would it be better to have a dedicated electric heater for winter and then a mini-split just for cooling vs. trying to have a mini-split that does both ?

If you go all electric get a mini split heat pump. Then use the electric heater as back up for when the mini can't keep up. Heat pump heat is much cheaper than straight electric so you'd want to use it as much as possible.

Though with nat gas on site running it to the shop is almost certainly the best long term option for heat in your climate. You'll just have to run the numbers to see how long it'll take you to break even.

 

[theoldwizard1]

Look at a PTAC heat pump with electric strip heat.

PTACs are notoriously INEFFICIENT and the electric heat strip is one reason why ! They are designed to be quickly/easily installed and removed. That is there only benefit.

Good mini-splits will pull "heat" out of the outside air down to below 0F without the use a heat strip. You have to learn how to read and understand the specs.

 

[theoldwizard1]

We put Mitsubishi Hyper Heat units in my wife’s basement exercise / tv room and another in our guest house. They heat ok down to about 13 degrees below zero, but are pretty ineffective at -16, based on our experience last winter.

You sound like you are complaining ! That sounds FANTASTIC !!

I wouldn’t recommend them as a sole heat source in much of northern Minnesota, but they are fine for our area, where the temperature is moderated to some extent by Lake Superior, as long as there is another heat source, like propane or resistance to get us through the few really cold days.

MODERATED by Lake Superior ????? Everything is relative. I guess when an arctic air mass comes across Superior it MIGHT warm up a couple of degrees compared to blowing across the Canadian tundra past that "single strand of barb wire" into MN !

 

[theoldwizard1]

If you go all electric get a mini split heat pump. Then use the electric heater as back up for when the mini can't keep up.

Anyone relying on a heat pump as a primary heat source needs a different backup than electric resistance. It will get awful cold awful fast if the power goes out !

Some kind of propane heat source (wall heater, fireplace, etc) is a good back up.

 

[MattT]

Anyone relying on a heat pump as a primary heat source needs a different backup than electric resistance. It will get awful cold awful fast if the power goes out !

For a house absolutely. That's why I have propane back-up for mine which doesn't require any electricity to run.

Not sure how that applies to a garage which isn't currently heated though

 

[yeldogt]

Hyper heat has nothing to do with size ... getting a hyper is about low temp operation.

The best hypers have the ability to provide full output down in the -5 range -- it's all about proper sizing based on load needed.

Even less expensive unit work in cold temps .. they just don't have as much output. Still cheaper vs resistance

 

[dneiding]

Hyper heat has nothing to do with size ... getting a hyper is about low temp operation.

The best hypers have the ability to provide full output down in the -5 range -- it's all about proper sizing based on load needed.

Even less expensive unit work in cold temps .. they just don't have as much output. Still cheaper vs resistance

I just purchased 6 indoor heads and three outdoor heat pumps from Alpine Home Air. I did not get hyper heat yet I was told my non-hyper units will heat down to -13 while hyper heats down to -22. I am still in the process of installing (and it's not the middle of winter yet here in northern Ohio) so I don't know how well they will work but these are the advertised specs.

 

[Conifer]

I’m definitely interested in learning more about this as I’ve been considering the Mitsubishi hyper heat units at our place for heating and cooling. Where I’m located, it rarely gets below -13 so I think they would be a good fit. It’s good to hear that they might actually be good down to -22, although I haven’t seen that information anywhere else yet, only the -13 figure.

 

[dneiding]

I’m definitely interested in learning more about this as I’ve been considering the Mitsubishi hyper heat units at our place for heating and cooling. Where I’m located, it rarely gets below -13 so I think they would be a good fit. It’s good to hear that they might actually be good down to -22, although I haven’t seen that information anywhere else yet, only the -13 figure.

I purchased mine from Alpine Home Air. I did not get HyperHeat (I have two forced air furnaces as back up heat for the few days a year I might need it). Here is an example of one of their HyperHeat units with the -22 spec:

https://www.alpinehomeair.com/viewproduct.cfm?productID=453076305

 

[SALIV8]

My minis will keep up down to about 26-28* F. Below that they still heat but can't satisfy demand.

I sized them for cooling And very happy with their performance so far.

 

[pbon]

I like the one that goes down to -22. We had some days that cold in my area. I should have considered one; I installed a window/wall AC and gas shop heater instead that probably cost the same and are probably less efficient.

 

[Kaoskido]

I just had an HVAC guy come check things out and we discussed MiniSplits/HeatPump and Radiant Heat plus the Mini Split and then PTAC.....

He said hands down to go with the PTAC

I know one of you guys on here mentioned the PTAC and I guess they are the units in the hotel rooms, etc.... but I have no idea how noisy they are --

Can they run all of the time I.e. heat garage during the winter and cool in the summer (on demand, etc) >

 

[finn]

You sound like you are complaining ! That sounds FANTASTICB !!



MODERATED by Lake Superior ????? Everything is relative. I guess when an arctic air mass comes across Superior it MIGHT warm up a couple of degrees compared to blowing across the Canadian tundra past that "single strand of barb wire" into MN !

Not complaining. It does exactly what I want.

As to Lake Superior moderating the local temperature, think about it. As long as the water is above freezing, it’s going to moderate the arctic blasts. Once it freezes over, we get the cold air from Canada full force, but the lake doesn’t normally freeze until late in the season, when the daytime temperatures are starting to rise.

Those living forty miles inland don’t see the moderation and it’s typically colder there.

They don’t suffer through 300” of lake effect snow to the extent we do, though.

 

[yeldogt]

still confusion on this thread.

A hyper heat Mitsubishi will maintain it's output down to the specification .... some are -5 some are 0. They have no problem doing this. Full rated output .. they also have a pan heater.

Don't mix up lowest operating temp with output at a particular temp ... most of the mini splits will work in cold temps .... but, unless they are designed to perform in cold temps ... you don't get the output when it gets really cold. They also can freeze.

Only the best units will work in really cold temps.

A PTAC -- is a through the wall unit. Many are heat pumps .... but not have great specifications ... and they all use resistance strips when it gets cold. They are loud.

They are designed to do a typical hotel room size -- they are loud.

 

[Kaoskido]

still confusion on this thread.

A hyper heat Mitsubishi will maintain it's output down to the specification .... some are -5 some are 0. They have no problem doing this. Full rated output .. they also have a pan heater.

Don't mix up lowest operating temp with output at a particular temp ... most of the mini splits will work in cold temps .... but, unless they are designed to perform in cold temps ... you don't get the output when it gets really cold. They also can freeze.

Only the best units will work in really cold temps.

A PTAC -- is a through the wall unit. Many are heat pumps .... but not have great specifications ... and they all use resistance strips when it gets cold. They are loud.

They are designed to do a typical hotel room size -- they are loud.

Apparently the HVAC guy I have access too does not know about this unit you mention.

I wonder how much they cost to cover a 23x23 garage and does it have heat strips or is just a heat pump? What about air flow and dust (wood working)? I have a air exchange and a dust collection system but there is still dust when wood working.

 

[dcg9381]

I think it's just a really efficient heat pump. But again, look at the performance graph.

BTU to cover space depends on insulation and how extreme the outdoor climate is. With a 23x23 - I'd think you could (easily) supplement with your own electric space heaters if absolutely needed.

 

[Jackfre]

Stay away from PTAC's. They are junk compared to the low temp spec mshp. If you go with mini-splits MAKE SURE YOU HAVE A CLEAR UNDERSTANDING OF THE SPECS OF THE UNIT OF YOUR CHOICE. I run Fujitsu's and know that line quite well, but there are multiple models of the same size that have different specs. Be clear on the model you choose and make sure you check that model number against what is delivered.
As the temp drops the efficiency does to. They do extremely well in the temps you see the majority of your winter. They become about like electric resistance at the very lowest temps. Ok, a bit better, but not much. The minis-split is the way to go for you. Get it in and live with it this winter. In extended sub-zero temps you may want to get a supplemental gas heater. Only experience will tell you that. You will love them in the summer.

 

[dsimatt]

We put Mitsubishi Hyper Heat units in my wife’s basement exercise / tv room and another in our guest house. They heat ok down to about 13 degrees below zero, but are pretty ineffective at -16, based on our experience last winter.

The units were installed about a year and a half ago to replace electric resistance baseboard heaters.

I wouldn’t recommend them as a sole heat source in much of northern Minnesota, but they are fine for our area, where the temperature is moderated to some extent by Lake Superior, as long as there is another heat source, like propane or resistance to get us through the few really cold days.

I'm close to the same weather as temps as you and my hyper heat had no issues at all even below -10 weather. The unit takes a lot longer to start putting out heat and reverses flow a lot more to but putted out all the heat we needed.

I'll agree in this region I'd want some other heat option preferably Nat Gas or propane style heater.

 

[justinjoyal]

I just had an HVAC guy come check things out and we discussed MiniSplits/HeatPump and Radiant Heat plus the Mini Split and then PTAC.....



He said hands down to go with the PTAC

Stay away from that guy !

 

[gtae07]

My Mr. Cool unit does fine with heat in the winter, but our lows rarely dip below 30F and we maybe have one day a year with a high below freezing. It's quite common to get warm spells around New Year's with highs in the 70s. On the two occasions I needed more heat, I brought an electric heater fan out.

The AC function, however, is crucial. It's a lifesaver 8 months out of the year.

 

[Kaoskido]

Thanks guys... I really know nothing about this heating and cooling and I live in a small rural area of Minnesota and it takes month of hounding to get an HVAC person to come out. I have their attention and they are telling me PTAC .... I called them back about the hyper heat Mitsubishi and he didn't have a clue what I was talking about. Yes, I am dealing one one individual that runs this small business I really have no other options as I have asked other providers to travel and they just never respond. I am looking to have my service panel upgraded and in doing so I am going to have a panel installed in the garage to feed more electrical outlets and give me the needed electrical to run out for a Mini-Split. I am going to ask the electrician if they have any heating solutions but I'd rather just go with the right MiniSplit and on really really cold days I just wont go in the garage. I googled our average temps for Dec, Jan and Feb and they are as high as 31 and low as 4 - but there are spells where we get into the below zero days.

If I had to force feed the HVAC to get the right unit what would I steer him towards?

Hyper Heat Mitsubishi (Model?? ) - or other alternatives?

Again, the garage faces the west - normal two car garage door, insulated and the garage walls and ceiling are insulated but to what R value I do not know.

 

[pbon]

Would it be easier to simply install a hanging natural gas or propane vented shop heater and a through the wall AC? You can DIY these jobs. No waiting.

 

[theoldwizard1]

I just had an HVAC guy come check things out and we discussed MiniSplits/HeatPump and Radiant Heat plus the Mini Split and then PTAC.....

He said hands down to go with the PTAC

I know one of you guys on here mentioned the PTAC and I guess they are the units in the hotel rooms, etc.... but I have no idea how noisy they are --

Can they run all of the time I.e. heat garage during the winter and cool in the summer (on demand, etc) >

I said it before. PTACS are cheap to install and expensive to operate !

They will use a "heat strip" (resistance heating, $$$) when the temps get down below 40F Not sure how well they will work below 10F.

 

[theoldwizard1]

... I live in a small rural area of Minnesota and it takes month of hounding to get an HVAC person to come out. I have their attention and they are telling me PTAC .... I called them back about the hyper heat Mitsubishi and he didn't have a clue what I was talking about.

You're screwed unless you do a self install.

Mitsubishi and Fujitsu are the top brands of mini-splits, but they really do not want to sell directly to home owner, especially for self installs. Other brands which have low temp heating (without resistance heat strips) are geared for self installation. Worst case, but one of these and pay the HVAC "flat rate" to install it. It should be less than 3 hours.

... a (breaker) panel installed in the garage to feed more electrical outlets and give me the needed electrical to run out for a Mini-Split.

Good idea ! A good quality mini-split would only require a 20A breaker. An electric heater/furnace might require a 50A breaker.

Now is a good time to re-assess the amount of insulation you have in the attic/ceiling. In MN, I would want a minimum a 12" fiberglass or cellulose.

If I had to force feed the HVAC to get the right unit what would I steer him towards?

Hyper Heat Mitsubishi (Model?? ) - or other alternatives?

If you decide to stay with Mitsubishi this is a good sales brochure. M-SERIES CONTRACTOR GUIDE

"Hyper-Heat" is also called "H2i". When purchasing a mini split system you usually have a choice of the type of interior "air handler". The typical model is the high mounted. Probably not the best for heat but good for cooling. The also make floor mounted unit. Mitsubishi also make ceiling cassette units and ducted units, but these are less efficient.

Your biggest problem with one heat source in a garage is distribution. Fans are required. Garage door seals are notoriously leaky. Not much you can do when it is below 20F and the wind is blowing > 20 MPH !

The size should be based on your heating requirements at 5F



Actually, the best solution is TWO interior "air handlers', but the price jumps up a lot and the efficiency drops.

 

[Jackfre]

I would suggest that you go to the mist and Fujitsu web sites and look up the dealers in your area. I would then contact the company directly to find out how to contact the area representative for MN. They should be able to tell you who has attended factory sponsored training locally...well, in your case, very broadly local.
You might also have a chat with your local Neanderthal HVAC guy and tell him there is some excellent equipment out there that he might want to look at. Don't say excellent "technology". That will scare him off.
For straight heat, I use and recommend the Rinnai Energysaver Direct Vent Gas Wall Furnaces. They are available from Ferguson Enterprises in your area.

 

[Fueler]

I just had an HVAC guy come check things out and we discussed MiniSplits/HeatPump and Radiant Heat plus the Mini Split and then PTAC.....

He said hands down to go with the PTAC

I know one of you guys on here mentioned the PTAC and I guess they are the units in the hotel rooms, etc.... but I have no idea how noisy they are --

Can they run all of the time I.e. heat garage during the winter and cool in the summer (on demand, etc) >

I had a PTAC for a year before I went mini split.
For me it's a Big NO on the PTAC.

 

[MattT]

The size should be based on your heating requirements at 5F

Just looked at some MN heating design temps and they're all negative. So no he shouldn't use 5*F for anything.