Looking to install a mini split...

[aaron1]

I forget if you have high wall units or floor units but does dog hair get up high on the high wall units?



I have similar old house with no ducts. Do you think you can live with the aesthetic? If you try and put the wall head in an out of the way place for looks then do you think the heat or cold will spread well?

I can live with the aesthetic. I've talked to several people who felt the same way and they don't notice anymore. It's amazing what humans can get used to with a little time. ha ha. Bedroom/upstairs placement would be no issue at all. The downstairs one would be a little unsightly, but I don't think it would be too bad.

My biggest concern is that since I have 2 stories with a very open stairway (pathway) between floors, that all of the heat from the first level will go up to the second level in winter and all of the cold from the second level will flow down to the first level in summer. The latter would actually work pretty well I think. The former could lead to some pretty uncomfortable conditions on the first floor. Actually, that is a fundamental flaw in 2-story houses regardless of what you're heating/cooling is, but mini-split placement would be critical to avoid the stairway robbing the first floor of heat I think. I read about this on a big report of mini splits in homes.

 

[maple1]

The house has one high and one floor mount. The floor mount is on the second floor where the dog doesn't go though. Hair stays low. It's all over the place in all the floor level nooks and crannies.

 

[maple1]

I can live with the aesthetic. I've talked to several people who felt the same way and they don't notice anymore. It's amazing what humans can get used to with a little time. ha ha. Bedroom/upstairs placement would be no issue at all. The downstairs one would be a little unsightly, but I don't think it would be too bad.

My biggest concern is that since I have 2 stories with a very open stairway (pathway) between floors, that all of the heat from the first level will go up to the second level in winter and all of the cold from the second level will flow down to the first level in summer. The latter would actually work pretty well I think. The former could lead to some pretty uncomfortable conditions on the first floor. Actually, that is a fundamental flaw in 2-story houses regardless of what you're heating/cooling is, but mini-split placement would be critical to avoid the stairway robbing the first floor of heat I think. I read about this on a big report of mini splits in homes.

We see that also. The lower level unit sends so much heat up the stairwell that the upper level one sometimes doesn't do much at all. Also, for heating, floor mount units (we have one upstairs) seem to give better feeling heat. If you have the lower wall space to put one. Which makes sense, since heat tends to rise - floor level can feel cooler at times with a wall mount unit up high.

 

[stoveliker]

I have high mount units, but have them blow almost straight down when heating (and almost parallel to the ceiling when cooling). It creates a rather even temperature distribution in the room air.

 

[aaron1]

I wonder if it makes sense for me to try installing one large unit in one of my "open" bedrooms upstairs and see if it can just cool my entire house from that location? Do you think that would work ok based on your experiences? I think I have to stick with wood and NG furnace for heating, but for cooling the mini split might be ideal, especially when I have no return ducts upstairs.

 

[stoveliker]

I did not do it that way. It depends on whether you want to sleep in the cold, or not... Your bedroom would be the coldest part of the home.

Also, if you like the air movement while sleeping, good. But if you don't (my wife does not...), you'd get all the heat from the home up there (b/c you're not cooling downstairs), and be limited in what you can do with cooling up there.

It might also short cycle a bit depending on how quickly the heat rises through the stairs, as the unit would be way oversized for the bedroom and thus cool it down quickly, after which it'll have to wait for more heat to rise up there before it kicks on again.

 

[aaron1]

I did not do it that way. It depends on whether you want to sleep in the cold, or not... Your bedroom would be the coldest part of the home.

Also, if you like the air movement while sleeping, good. But if you don't (my wife does not...), you'd get all the heat from the home up there (b/c you're not cooling downstairs), and be limited in what you can do with cooling up there.

It might also short cycle a bit depending on how quickly the heat rises through the stairs, as the unit would be way oversized for the bedroom and thus cool it down quickly, after which it'll have to wait for more heat to rise up there before it kicks on again.

Actually, sleeping in the cold in the summer sounds pretty nice to me! I would put the unit in a different bedroom and just crack the door on my main bedroom to allow more circulation. Or maybe I'd need a small unit/window unit in my bedroom for complete control and the bigger one running to do the rest of the house.

I think the heat would easily go up there continuously like a Gulf Stream in my house. I get a crazy convection current going when I use the wood stove in the winter with hot air running up the top of the stairwell ceiling and cold air flowing down the stairs. Good point that it might chill the room down too quickly though if the fan isn't adjusted right. That's part of the problem with these things. It's hard to know what will work until you put something in and try it (if someone else hasn't done it.)

Maybe it would make more sense to put the main big unit in the central landing at the top of my staircase.

 

[aaron1]

maybe one of these FOUR WAY CEILING CASSETTES in/on the ceiling of my second floor landing/foyer would work better. it would cost quite a bit more than the simpler heads but it would be my central ac for the house, so maybe worth it

Ceiling Cassette Mini Split AC & Heat Units | Mitsubishi Electric HVAC

Choose between sleek recessed ceiling cassettes and suspended units with ceiling HVAC options from Mitsubishi Electric. Manage air flow with individual vent controls.

www.mitsubishicomfort.com

 

[stoveliker]

Good point that it might chill the room down too quickly though if the fan isn't adjusted right. That's part of the problem with these things. It's hard to know what will work until you put something in and try it (if someone else hasn't done it.)

Maybe it would make more sense to put the main big unit in the central landing at the top of my staircase.

That "problem" is a problem of sizing the unit, and a decent installer will be able to do that for you, based on volume, insulation, window area, orientation of the home, and sun exposure. But, they'd default to "a unit sized for the room", so you would have to carefully explain to them that you want to use it in a different way.

Also, if you will truly only cool, the units are cheaper than the systems that can cool and heat. So maybe the cost of the four-way cassette is somewhat offset by the cooling only system price. I do see the SLZ needs a 2 ft x 2 ft area to mount (and your joists are not likely that far apart...).

[caveat though: I'm a user, and not an expert on these things...]

 

[aaron1]

That "problem" is a problem of sizing the unit, and a decent installer will be able to do that for you, based on volume, insulation, window area, orientation of the home, and sun exposure. But, they'd default to "a unit sized for the room", so you would have to carefully explain to them that you want to use it in a different way.

Also, if you will truly only cool, the units are cheaper than the systems that can cool and heat. So maybe the cost of the four-way cassette is somewhat offset by the cooling only system price. I do see the SLZ needs a 2 ft x 2 ft area to mount (and your joists are not likely that far apart...).

[caveat though: I'm a user, and not an expert on these things...]

Yeah, I saw the cooling ones would be cheaper. I thought maybe I could mount the ceiling cassette to the ceiling and build a small trim box around it. I need to talk to someone who knows what they're doing. I just like to have thought about everything beforehand so I don't get led down the wrong road. Thanks!

 

[EbS-P]

I can live with the aesthetic. I've talked to several people who felt the same way and they don't notice anymore. It's amazing what humans can get used to with a little time. ha ha. Bedroom/upstairs placement would be no issue at all. The downstairs one would be a little unsightly, but I don't think it would be too bad.

My biggest concern is that since I have 2 stories with a very open stairway (pathway) between floors, that all of the heat from the first level will go up to the second level in winter and all of the cold from the second level will flow down to the first level in summer. The latter would actually work pretty well I think. The former could lead to some pretty uncomfortable conditions on the first floor. Actually, that is a fundamental flaw in 2-story houses regardless of what you're heating/cooling is, but mini-split placement would be critical to avoid the stairway robbing the first floor of heat I think. I read about this on a big report of mini splits in homes.

I got one of these thinking it would help keep heat on first floor and it does. Can be trip hazard on stairs going up. Probably not worth the cost. But it’s easy to take down and put back up.

VIZ-PRO 6PCS Strip Door Curtain, 84" Height X 36" Width, 0.08 Inch Thickness Standard Clear PVC Curtain Strip with 56% Overlap for 3' X 7' Doors Amazon product ASIN B07W6PQS2W

 

[aaron1]

I got one of these thinking it would help keep heat on first floor and it does. Can be trip hazard on stairs going up. Probably not worth the cost. But it’s easy to take down and put back up.

VIZ-PRO 6PCS Strip Door Curtain, 84" Height X 36" Width, 0.08 Inch Thickness Standard Clear PVC Curtain Strip with 56% Overlap for 3' X 7' Doors Amazon product ASIN B07W6PQS2W

now that I can't live with. ha ha ha ha. thanks for the recommendation though.

 

[RustyShackleford]

Also, if you will truly only cool, the units are cheaper than the systems that can cool and heat.

On the flip side, is there such a thing as a heat-only one ? We just bought a vacation/rental home in the mountains at 4000+ ft. Don't think it needs any A/C (doesn't have it now, and people claim you don't need it there). But the existing heat is electric baseboard, as well as a couple of electric-resistance wall-mounted heaters. So I expect the electric bills to be horrifying. The living room, kitchen, etc are upstairs and the bedrooms downstairs. We like to sleep cold, so I'm thinking just put a mini-split upstairs, and use the electric-baseboard sparingly downstairs.

 

[stoveliker]

I don't think there are heat only minisplits, but I might be wrong.

Your plan sounds reasonable.

 

[EbS-P]

On the flip side, is there such a thing as a heat-only one ? We just bought a vacation/rental home in the mountains at 4000+ ft. Don't think it needs any A/C (doesn't have it now, and people claim you don't need it there). But the existing heat is electric baseboard, as well as a couple of electric-resistance wall-mounted heaters. So I expect the electric bills to be horrifying. The living room, kitchen, etc are upstairs and the bedrooms downstairs. We like to sleep cold, so I'm thinking just put a mini-split upstairs, and use the electric-baseboard sparingly downstairs.

The dehumidification even if you didn’t need the cold air could be useful. It all depends on how much time the heat is running. I did the math and unless I do a DIY mini split install it would be cheaper to run resistive electric heaters for somewhere between 5 and 10 years than paying for a Mitsubishi unit to be installed.

 

[stoveliker]

But you use less kWh (produce less CO2) heating with the minisplit - though I don't know how that is offset when the production CO2 cost is distributed over the lifetime of a minisplit ...

And with a minisplit that's not at the end of its life, one has added value in the property.

 

[RustyShackleford]

The dehumidification even if you didn’t need the cold air could be useful. It all depends on how much time the heat is running. I did the math and unless I do a DIY mini split install it would be cheaper to run resistive electric heaters for somewhere between 5 and 10 years than paying for a Mitsubishi unit to be installed.

Man, that's hard to believe. Looks like winter electric bills at this place run about $500/month. Say 4 winter months, so $2000; a minipslit with COP=3.5 would save about $1400. Per year. OTOH, it's a vacation place, so likely to be empty a lot, though must have some heat to prevent pipes freezing; also, we plan to rent it some (required to, since I'm using a tax-free 1031 like-kind exchange to avoid paying mondo cap-gains tax on some land I'm selling to help pay for the place), and renters are likely to be less parsimonious of electricity. So it's complicated.

I don't expect install to cost that much. I will do everything myself except the freon, and hope to get the moonlighting cryogenic tech who's done HVAC work for me before to go do the freon, maybe in exchange for a week at the place with his family.

Good point about the summer dehumidification. I'll forget about a heat-only unit, probably not a whole lot cheaper anyhow (if it exists).

 

[peakbagger]

Barring what is going on in Washington, there could be large incentives to install mini splits to decarbonize the grid soon. The trade off is the refrigerant used in most minisplits, R410A is being phased out at the end of this year (banned in new equipment in 2023). There could be a price increase and supply shortage of units as the 410A units are cleared out of inventory . BTW the replacement R32 is flammable and may take a few years to figure it out so reliability may take a hit. R410 will still be available but the reality if with mini splits units they rarely need recharge.

 

[EbS-P]

I was quoted 6k$ plus electrical work for a 15k btu Mitsubishi unit. That was the low quote. it’s only 1000 sq ft basement. Has heat now, but not enough.

Sometimes spending the money makes money.

 

[RustyShackleford]

I was quoted 6k$ plus electrical work for a 15k btu Mitsubishi unit. That was the low quote. it’s only 1000 sq ft basement. Has heat now, but not enough.

What was material versus labor breakdown ?

 

[peakbagger]

What was material versus labor breakdown ?

Looking on Ebay for Mitsubishi 15 K reasonable SEER cold climate unit I see the unit is in the 2800 K range (less for second tier brands). Add in a tubing kit, wall bracket and tubing chase between the outdoor unit and the indoor unit and my guess is $300 extra for materials. The units are set up for 25 foot tubing run, if its longer than the installer has to put in more refrigerant. So if its standard install the labor is roughly double the cost. Electrically you need a 20 amp 240 volt circuit (12-2) with a unfused outdoro disconnect box on the wall next to the minisplit outdoor unit. If you have the right size core drill to drill through the wall, not a lot of special tools. At best it should take the tech 3 hours to connect up the tubing, purge the lines, pump them down and open the taps. The one caveat is Mitsubishi and I think Fujitsu sell through dealers whe are responsible to administer the warranties. If you buy one direct on the web, the seller may be dealer and may replace a dead on arrival if you ship it back unit but highly unlikely they will do anything about a bad compressor 2 years from now.

The dealers know these are extremely reliable and usually the reason they die is external damage by the owner so its likely they will get paid to replace the unit.

 

[fbelec]

the problem with installing a unit upstairs and trying to cool downstairs with it, in theory might work but once you put people in place it starts to warm up. and have company over and it's running warm downstairs. you are better off running one upstairs and one downstairs. if they are keeping the same temp then the crossover temps from first to second floor are minimal. also if you have one in your bedroom and don't like the wind samsung makes a windless option. i just wired a samsung compressor with 4 heads last week that had the option.

 

[RustyShackleford]

the problem with installing a unit upstairs and trying to cool downstairs with it ...

Not sure if you're talking about my situation, but ... I don't think this place is going to have any cooling needs, being over 4000ft elevation. Heating is my only concern, and trying to not incur the costs of the purely electric-resistance heating that's in the house now. Of course, trying to heat downstairs with an upstairs mini-split is even more problematic. But my attitude is that we want the common living spaces (the upstairs of our new house) to be much warmer than the sleeping areas (which are all downstairs). So just rely on the existing electric baseboard for the bedrooms.

My main issue at this point is whether to use one of the DIY-friendly minisplits (with pre-charged line-set) or do most of the installation work of a conventional one myself, and see if I can hire an HVAC professional to handle the freon; depends on how much the pro needs work and how much he trusts me, I suppose.

 

[fbelec]

no rusty wasn't talking about your sit.
but the nice thing about having electric baseboard heat is if one goes out the rest will keep it warm. almost like a insurance for heat. i understand if the power goes out but it will be that way on any heating but wood. if you were looking to heat electrically from a generator the mini split is the way to go. there is no startup current surge it starts low and ramps up to lower run power than a conventional heat pump. just went to samsung mini split school. one of the nice things about a samsung is they have a heat pump mini split that is called a windless. great for a bedroom so that you don't feel the breeze and think it's colder than it is. just remember you get what you pay for. so buying that cheap unit yes it may work for the next two or three years but the potential for failure is higher. the prices for the units are high but it's not necessarily the guy putting it in that makes it cost so much. and i find in my experience that 8 out of 10 people either get the wrong stuff or forget something that will cause the contractor to make more trips and cost the home owner more money. the only thing that i tell the home owner to buy is a light fixture. because everybody's taste is different. in my first couple of years doing this i got burn't one to many times buying them.

 

[RustyShackleford]

no rusty wasn't talking about your sit.

So, you're saying buy a name-brand unit (not the DIY type), and have a pro install it ? I'd at least do the electric myself.
That Samsung "windless" thing sounds great.