Mitsubishi Heat pump quote

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MapleHill

New Member
Jan 22, 2021
12
Vermont
My issue with wood heat is: who manages it when I'm gone?
No,... not dead,..... gone as in a long weekend away, or any winter vacation?
I see your avatar has a pellet stove, and that's a good 24 hr operating window, but to me wood heat has always been supplemental.
I'd get the lowest outdoor temp operating unit for that reason alone.
Good point, Cap'n. I neglected to mention that our 2nd source of heat is oil hot water. So that's our backup or primary depending on the price of pellets. But good point, it'd be nice not to worry about frozen pipes over a long weekend.
 

Woodspliter

Member
Jan 25, 2020
131
Maine
Peak I do agree to a certain degree with you. I think that they're are disposable units to a certain degree. There is some sensitive electronics inside these things. I'm installing a whole home surge protector. So unless someone crashes into a outdoor uint or lightning strikes twice I should be covered!I have totall faith in these mitsubishi's. But you never know chit does happen my opinion is that, it's is a small price to pay for pice of mind. The new FS is supposed to have a coating on the indoor units to help them stay cleaner. I agree keeping them clean is the single most important thing to keep them efficient and dependable other than proper installation.
 

DuaeGuttae

Minister of Fire
Oct 26, 2016
953
Texas
How bad are these for DIY install? Thinking about getting some portable AC units for summer time, but two mini splits would be nice. I haven't read the Maine rebate small print in a while, does it cover DIY install?

Edit: Also curious as to how to size the unit(s). Our house is a small well insulated saltbox and our primary heat is a 32kbtu peak rated wood stove.
Spacebus, have you seen @Brian26 ‘s thread about the Midea U-Shaped air conditioners from last year? They’re basically little inverter air conditioners that install similarly to a traditional window air conditioner, but the u-shaped design keeps more of the noise outside. We ordered two through the introductory promotion last year, and there was some damage to one of the units in shipping. Midea replaced the unit in a much better packed shipping container, and we’ve really been impressed with the units.

My husband works at home now, and his office doesn’t have HVAC directly to it. It just benefits from two neighboring rooms. We didn’t need to cool those rooms during the day, though, so this unit allows him to cool his office efficiently. The other we put in our big downstairs open plan area (kitchen, dining room, family room, school/craft/garden room) where we spend all of our time. During hot but not brutal times it allows us not to use the central air in the area, though it really can’t keep up during extreme Texas heat because our area is oversized for its specs.

In our case, it allows us to air condition more efficiently than running central air units unnecessarily. In your case, of course, you would be adding air conditioning, but I wanted to point these out as a much easier and cheaper alternative to traditional mini-splits.

Just google Midea U-shaped air conditioner if you’re interested in checking them out.
 
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SpaceBus

Minister of Fire
Nov 18, 2018
5,948
Downeast Maine
Spacebus, have you seen @Brian26 ‘s thread about the Midea U-Shaped air conditioners from last year? They’re basically little inverter air conditioners that install similarly to a traditional window air conditioner, but the u-shaped design keeps more of the noise outside. We ordered two through the introductory promotion last year, and there was some damage to one of the units in shipping. Midea replaced the unit in a much better packed shipping container, and we’ve really been impressed with the units.

My husband works at home now, and his office doesn’t have HVAC directly to it. It just benefits from two neighboring rooms. We didn’t need to cool those rooms during the day, though, so this unit allows him to cool his office efficiently. The other we put in our big downstairs open plan area (kitchen, dining room, family room, school/craft/garden room) where we spend all of our time. During hot but not brutal times it allows us not to use the central air in the area, though it really can’t keep up during extreme Texas heat because our area is oversized for its specs.

In our case, it allows us to air condition more efficiently than running central air units unnecessarily. In your case, of course, you would be adding air conditioning, but I wanted to point these out as a much easier and cheaper alternative to traditional mini-splits.

Just google Midea U-shaped air conditioner if you’re interested in checking them out.
Unfortunately we don't have a single double hung window in the house. I do really like the idea of these Midea "U" units and would do it if we had different windows.
 

EbS-P

Minister of Fire
Jan 19, 2019
802
SE North Carolina
I’m getting some quotes for a mini split this week and wondered if if anyone thinks a generator transfer switch for a mini split is a good idea. I don’t have a transfer switch at my panels but have considered it.




Evan
 

Brian26

Minister of Fire
Sep 20, 2013
603
Branford, CT
I’m getting some quotes for a mini split this week and wondered if if anyone thinks a generator transfer switch for a mini split is a good idea. I don’t have a transfer switch at my panels but have considered it.




Evan
Way easier and cheaper to just wire a plug on your mini split wires from the disconnect and plug it right into the 220 generator outlet. The wires are easy to access inside the disconnect. I installed a whole house transfer plug but had 2 plugs and wires ready to go for both my splits before I did that.

Another plus with mini splits on generators is there is zero start up stage on them.
 

Woodspliter

Member
Jan 25, 2020
131
Maine
I have a gentran box out the outside of my house and an interlock switch so I can back feed right to the panel. Simple easy and not much money
 

DuaeGuttae

Minister of Fire
Oct 26, 2016
953
Texas
Unfortunately we don't have a single double hung window in the house. I do really like the idea of these Midea "U" units and would do it if we had different windows.
Oops. I think maybe I’ve even mentioned them to you before. Casement windows ring a bell. I misread your wording of “portable” as “window” air conditioners.
 
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tabner

Burning Hunk
Jan 17, 2019
146
Eastern CT
@Woodspliter i think you got a good deal. I had one outdoor unit (MXZ-3C30NAHZ2-U1) installed with three indoor heads (2, MSZ-GL06NA-U1, and 1, MSZ-GL15NA-U1). I paid 11,800 (after the rebates) for the whole system installed with the 12 year warranty (and 3 year labor warranty).
Only complaint so far is I should have sprung for the branch box and had all the lines run off a box in the attic. Instead the whole back of my house is covered in line hide. But that's my fault.
Does anybody know if my model is the -5 or -13? It's supposed to be hyper heat, but i didn't realize there were two temp mins.
 

Woodspliter

Member
Jan 25, 2020
131
Maine
Yeah tanner, when I talked to the first installer about a 36k multi zone he said the branch box was like 1500 bucks plus labor and need to run a 8awg wire for another circuit, I quickly decided against that. I love The fact of the 3 singles other than cluttering up the exterior of the house in witch they won't be visible for the road but the extra Efficiency and being able to run them independently of each other nevermind the fact that they're more cost effective was the deciding factor .
 
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Brian26

Minister of Fire
Sep 20, 2013
603
Branford, CT
Where these units really shine are being able to heat and cool just one room or area. Below is a good example. I have 3 independent single zone 12k units. With my wife working from home the last year she setup her office right under our downstairs unit and she loves it. No need to keep the entire house at 70 when she's just working in 1 room. I know other people getting huge bills keeping their entire house at 70 when its just 1 person in 1 room working from home.

20210304_202521.jpg
 

SpaceBus

Minister of Fire
Nov 18, 2018
5,948
Downeast Maine
How much more efficient would three separate mini splits be compared to one larger one with three zones?
 

Brian26

Minister of Fire
Sep 20, 2013
603
Branford, CT
How much more efficient would three separate mini splits be compared to one larger one with three zones?
They are usually much more efficient when you compare SEER and HSPF numbers. The main issue with them is they are usually way oversized.

Single zone units have a much lower turn down ratio. A 12k single unit can modulate from lets say 1200-12000 btus. A 36k btu Mitsubishi multi split will usually have a range of like 9k-36k btu. Those higher minimum speeds are often too much for the actual load. The multi splits have losses as they are pumping refrigerant to each head even if they aren't on.

Here is a good example. You have 3 rooms each with their own 12k units. In the summer a room might only need 1500 btu/hr of cooling. The single zone units can throttle down that low. The lower the load the greater the efficiency with mini splits.

Lets say you have a 36k btu multi split with a 12k head in each room. Since the minimum cooling output is 9k if your ran just one head you are oversized by 6 times. Running all 3 your still oversized by 2.

A 36k multisplit might draw lets say 1000 watts at minimum speed supplying 9k. A single zone can supply 1500 btus and only use like 100-150 watts each. The multisplit is using like 3 times the power and is ridiculously oversized.

On another forum there are endless posts about people getting massive electric bills with these multi's. Maine knows this is an issue and that is why they are only giving out the incentive to single zone units. Its now widely recommended on most green building forums to install multiple single zones.

You also get redundancy. It would take all 3 of my single zones to break for me to lose heat. On a multi split all your units go down. Its also easier to repair a single zone if there is a leak. A single zone has 2 refrigerant lines and 4 flare fittings. A 3 unit multisplit has 6 refrigerant lines and 12 flares between condenser and inside units. They are challenging to get installed leak free as there are so many connections thar can leak and the unit goes down. Much easier to trace a leak on a single zone.
 
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DBoon

Minister of Fire
Jan 14, 2009
1,248
Central NY
Here's a question: if one planned to only use the heat pump about 30 degrees (outside) and up... is it worth paying more for the -13 series or should one settle for a -5 or 5 degree unit? I would heat with wood below 30 degrees so it doesn't make much sense to me to pay extra for the ultra low temp models.
The units that operate in very cold temperatures are typically much less efficient overall, perhaps by a factor of 1.5. If you already have something else as backup heat (besides your woodstove), then I think it would make the most sense to install a unit that operates at higher outdoor temperatures and just switch to the other backup heat source as needed below that temperature.
 

EbS-P

Minister of Fire
Jan 19, 2019
802
SE North Carolina
I just got a quote of $4000 not including electrical work for a single 15k BTU unit MUZ-FH15na
MSZ-FH15NA

another outfit wanted $6700 for 27k btu unit for the same space. Install can’t get much simpler. I think I’m going to look at a Blaze King insert and skip the mini split or DIY it.

Seems like you are getting a good deal but prices down here near the beach can be steep any time you need quality tradesman work.
Evan
 

SpaceBus

Minister of Fire
Nov 18, 2018
5,948
Downeast Maine
I just got a quote of $4000 not including electrical work for a single 15k BTU unit MUZ-FH15na
MSZ-FH15NA

another outfit wanted $6700 for 27k btu unit for the same space. Install can’t get much simpler. I think I’m going to look at a Blaze King insert and skip the mini split or DIY it.

Seems like you are getting a good deal but prices down here near the beach can be steep any time you need quality tradesman work.
Evan
This is the issue I have living in "Vacationland", especially on the coast. As a result I don't really hire many things out. So far the only thing I couldn't do myself was secure and install a new utility pole and some emergency plumbing work. Even if you could afford to hire any tradesmen, they are always booked out working for vacationers or landlords. The DIY looks like a better deal even if I can't get the rebates.
 

Woodspliter

Member
Jan 25, 2020
131
Maine
Space bus I price just the equipment for my install and it was in 6700 bucks on an internet wholesale gotductless.com. for 3200 bucks for a complete install with foundation brackets linsets and wiring I think it's a no brainer!
 
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maple1

Minister of Fire
Sep 15, 2011
10,783
Nova Scotia
The units that operate in very cold temperatures are typically much less efficient overall, perhaps by a factor of 1.5. If you already have something else as backup heat (besides your woodstove), then I think it would make the most sense to install a unit that operates at higher outdoor temperatures and just switch to the other backup heat source as needed below that temperature.
I am not following. Units rated for colder temps should be more efficient? Isn't that why they can rate for lower temps - increased efficiency?
 

DBoon

Minister of Fire
Jan 14, 2009
1,248
Central NY
Hyperheat and similar units are rated for efficient operation, e.g., a COP of 2.5 or 3, at lower temperatures, e.g., -5 degrees F. But hyperheat-type units may have a COP of only 3 at 40 degrees or so. A unit incapable of operating or generating heat at -5 degrees F may provide COPs of 4 or 5 at 40 degrees F.
 

MapleHill

New Member
Jan 22, 2021
12
Vermont
Thanks for that info. In the end, I decided to go for the newest generation of HyperHeat (FS series). I decided that if I'm going to be spending for a backup heat source, it's worth getting one that can make heat in low temps.
 
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Brian26

Minister of Fire
Sep 20, 2013
603
Branford, CT
Hyperheat and similar units are rated for efficient operation, e.g., a COP of 2.5 or 3, at lower temperatures, e.g., -5 degrees F. But hyperheat-type units may have a COP of only 3 at 40 degrees or so. A unit incapable of operating or generating heat at -5 degrees F may provide COPs of 4 or 5 at 40 degrees F.
This is very true. If you don't plan on operating the unit at extremely low temperatures its better to get a non hyper heat version.
 

begreen

Mooderator
Staff member
Nov 18, 2005
88,225
South Puget Sound, WA
This is very true. If you don't plan on operating the unit at extremely low temperatures its better to get a non hyper heat version.
Agreed. The COP at 17º is more meaningful for our region.
 
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DBoon

Minister of Fire
Jan 14, 2009
1,248
Central NY
What is the cop comparison of let's say the fs 9k btu and the rating of the equivalent non hyper heat?
It's been a while since I've done these calculations, but basically you have to find the manual that includes the performance characteristics at different operating temperatures (this isn't widely available - will take some internet sleuthing), and then do your own COP calculation (output/input). Usually, they have output in BTUs and input in Watts, so you have to watts to watt hours and then convert BTUs to watt hours at 3414 BTU/kWh.
 

UpStateNY

Feeling the Heat
May 4, 2008
401
Catskill Mountains
Up here in NY state I think a COP of only 3 at 40 degrees is just fine. Really how much heat do you need to generate at 40 degrees. Its been around 30 to 50 degrees this last week and I see almost no change in my electric usage using my -15 degree 24K multi heat pump compared to previous week using propane boiler for heat.