Costco now selling DIY mini splits.

Highbeam

Minister of Fire
Dec 28, 2006
17,230
Mt. Rainier Foothills, WA
Sure I could install more units but hard to justify 3K for something that wouldnt need t be used often.
I don't think it is hard to justify when people spend 10-15k installing a central system. Incrementally you are spending 3k more for that little bit of need but as a system your cost is 3k more for a system that does the job vs. one that doesn't.

Nice to have a redundant heat pump in case of failure too. If each unit (assuming you need 2) is running at 50% throttle that will be quieter, more comfortable, and perhaps more efficient than one unit running at 100%.
 

Swamp_Yankee

New Member
Oct 18, 2018
59
Hunterdon County, NJ
It should be great for shoulder season heating. I'd try it out.
I'd have to make sure there wasn't any redundancy between our boiler (Buderus with Logamatic 2107 controller) and the mini-splits. The Logamatic controller does very well at dialing in the needed amount of water heating based on the outdoor temperature and the return temperatures. I'll have to talk to my boiler guy.
 

maple1

Minister of Fire
Sep 15, 2011
10,462
Nova Scotia
I'd have to make sure there wasn't any redundancy between our boiler (Buderus with Logamatic 2107 controller) and the mini-splits. The Logamatic controller does very well at dialing in the needed amount of water heating based on the outdoor temperature and the return temperatures. I'll have to talk to my boiler guy.
I don't think I would be too worried. With the mini-splits running, there would simply be less heat demand & less call for heat from the oil thermostats - the outside temp isn't what controls the heat delivered to the house. I suppose there could be a bit of an increase in stand by heat loss, if the boiler was being kept hotter than absolutely needed. But those are pretty decent boilers with minimal loss to start with.
 

peakbagger

Minister of Fire
Jul 11, 2008
5,297
Northern NH
I think Mitsubishi and LG have some sort of proprietary control net ports built into their units that allow remote control of their systems to integrate with other equipment. Commercial buildings probably can afford to use this option but expect a homeowner would not.
 

hockeypuck

Feeling the Heat
Sep 6, 2009
314
south central NH
I think Mr. Cool did their homework as far as their intended customer base with these units. If you're willing to buy one, run the dedicated 20A/240V circuit yourself, mount the units, drill a hole in the side of your house, etc...you're not just going to continuously call an HVAC pro for repairs and "hold their responsible," if and when something goes wrong. Rather, they are going to figure it out themselves or find someone who can help. I spoke with a buddy who is an HVAC pro who told me that if I ever had issues that he would look at it, and in all likelihood the parts were generic. These things are all made by two or three huge companies in China and a lot of the parts are the same.



I doubt I'll ever use mine for heating. For us these were a low-cost DIY solution to a 120 year old farmhouse with no AC and no ductwork and so far it's working great. After enduring last summer either being uncomfortably hot while trying to sleep at night and/or having to sleep with the drone of a window shaker in my ear, this summer is a dream come true. We set the unit to "Dry" at night before we go to bed. It runs just enough to cut the humidity down-last night we were sitting in our bedroom watching the evening news and though it was 78°F in the room we were perfectly comfortable because the humidity was so low.
Just as an update on my Mr Cool Unit.. I have been using it to warm our living area on mornings that are above 28 F. I underestimated the number of times I would use it as a heat pump. If I get 3 years out of this thing, it will be more that worth it. I would recommend one to any mechanically inclined DIYer. Even if it give up the ghost in a few years, I still have the electrical hook ups for a new unit. So glad I do not have to look forward to dragging the three window units up from be basement anymore. Moral of the story, go do some online research and if you are thinking of getting one, order it now and take you time to do the install before the heat arrives.
 

mustash29

Minister of Fire
Feb 6, 2012
675
SE CT
Interesting thread.

I have an 1800 sqft tri level. Main floor is bedrooms (garage below on slab), kitchen & dining room (rec / stove room below on slab). Go down a half flight of stairs to the sunken living room & foyer with 12' ceilings & big windows (basement below). Go down another 1/2 flight of stairs to rec / stove room. This is a slab and even with the garage slab.

Currently getting by with a noisy 8K in the bedroom window and (believe it or not) a good old fashioned 1982 GE/Hotpoint 12,800 btu R-12 "freezer" with an EER of 12 in the living room. Problem is the MBR is the south west corner of the house and bakes in the middle of the day. Kitchen is west side and bakes in the late afternoon sun. Living room is cold. Rec room and basement humidity are a non-issue. Worst part - I am a 12 hr shift worker so sleeping in a hot MBR is no good.

Got quotes for -
$10 K for a 3 ton Mitsubishi central A/C unit to hit the main level, or
$9 K for a 27 K Mitsubishi hyper heat compressor with 9K head in MBR & 18 K head in other end of house, or

$7 K for a 24 K Fujitsu XLHT with 9K head in MBR & 18 K head in other end of house.

Or I could just do 2 DIY's for about 3 K.

Heat is a non-issue. I like my oil HW baseboards & wood stove (soon to be boiler). Also have a 6 K Nyletherm to hook up to the DHW so basement / rec room humidity is definitely not a concern.

Decisions.....decisions.
 

Highbeam

Minister of Fire
Dec 28, 2006
17,230
Mt. Rainier Foothills, WA
I would never say heat is non issue. It’s a nonissue to purchase a heat pump that heats and cools. This way you have a source of heat that can be used as a backup, supplement, or maybe even cheaper alternative to oil.
 

maple1

Minister of Fire
Sep 15, 2011
10,462
Nova Scotia
I would never say heat is non issue. It’s a nonissue to purchase a heat pump that heats and cools. This way you have a source of heat that can be used as a backup, supplement, or maybe even cheaper alternative to oil.
Exactly. I see no reason to put in cooling only mini-splits, when they can make heat cheaper than anything else out there. Except maybe NG where it is priced cheap (some places it's not).
 

peakbagger

Minister of Fire
Jul 11, 2008
5,297
Northern NH
My original Mitsubishi minisplit is a cooling only unit. It went in before the hyperheat technology was being marketed in the US. There was a heat option for extra dollars but the option was not capable of cold weather operation, I think the old units turned off when it went under 45 degrees. I would like to swap it over to hyper heat cold climate unit but hard to justify junking a unit that has been running perfectly for over 10 years. The tubing run from my unit to the outdoor unit is complex and since it was installed I had some foam work done that makes replacing the tubing a major project. I have been advised that many installers will not guarantee a new install using the old tubing due to fear of incompatible lubricant. On the other hand I have talked to a couple of techs and they feel as long as the refrigerant is the same it should not be an issue unless the compressor "burns up" and pulls crap into the tubing.

Be aware that the clock is ticking on the current refrigerant used for many minisplits, there are replacement gases but its going to lead to initial price increases and potential reliability issues on the ramp up. The old refrigerants will still be available for service but the reality is unless its a bad install or external damage, rarely do known brand minisplits need a recharge.
 

Brian26

Feeling the Heat
Sep 20, 2013
493
Branford, CT
The game changer is if you have solar panels with net metering and mini splits. No fossil fuels being burned and your heat is essentially free. I only pay $10 a month for the connection charge. I dont even bother burning wood much anymore. I set my splits to 70 and the house is maintained perfectly at that temp.

Here are my panels powering both my mini splits and sending most of the power back to the grid. Both of my 12k mini splits have been pretty much running nonstop this whole winter. Its staggering how little power they actually use. Both units combined have averaged 500 kwhs in Jan and Feb.

Screenshot_20200224-173724_Monitor.jpg
 

peakbagger

Minister of Fire
Jul 11, 2008
5,297
Northern NH
Brian and I may not agree on running them in very cold weather, but I completely agree that minisplits with solar and a good net metering contract is a home run. If someone has the real estate for extra panels, its not that expensive to add a few extra panels to cover the mini splits.

The key is to make sure the details on the utilities net metering fit. The best net metering is a perpetual option where the utility never resets the contract. Many utilities do a yearly reset where they either buy any surplus and reset the contract at a certain date or they just reset the contract and keep the surplus with no compensation at that date. If the reset date is in the fall then summer surplus really is of no value for the winter. If its in February or March then its a better fit.

I have the perpetual version and try to carry a surplus of 600 kwh at the low end of the year which is usually February. I start running the mini split more often if I am over the target but if I am getting close I run the wood boiler a bit longer. Once March comes around and my solar output bumps up big time, then I swap over to the minisplit once nigh time temps are over 20 F.
 

semipro

Minister of Fire
Jan 12, 2009
3,810
SW Virginia
I just installed a 2 ton diy mr cool. Did everything myself. Install was pretty easy. Works great. Obviously longevity is a concern, but since I do not live in Florida where AC is a must, I felt the savings was worth the risk. So glad the noisy window units are no longer needed. It is quiet inside and out. Outside side condenser is surprisingly quiet, so those who might be afraid of disturbing neighbors...
Are you still happy with this unit? I'm considering replacing my 2 older ducted central units with two Mr. Cool Universal systems.

I'd be willing to pay more for better quality but the price of the Mitsubishis and Daikens seem to be much unreasonably higher.
 

Seasoned Oak

Minister of Fire
Oct 17, 2008
7,071
Eastern Central PA
I would never say heat is non issue. It’s a nonissue to purchase a heat pump that heats and cools. This way you have a source of heat that can be used as a backup, supplement, or maybe even cheaper alternative to oil.
Agreed ,no way would i want cool only. In pa we need both sometime in the same week. Getting one installed this week , by my tenant who is behind on his rent and is a cert. HVAC. Im planning to go from a little wood and mostly coal to Mini and more wood for heat. The coal is cheap but dusty even though i have hot water baseboard. Ill save it for the 2 worst months of the winter. Ill have less than 1k in a 1 ton unit. Unit and Materials about $600.
 
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maple1

Minister of Fire
Sep 15, 2011
10,462
Nova Scotia
Agreed ,no way would i want cool only. In pa we need both sometime in the same week. Getting one installed this week , by my tenant who is behind on his rent and is a cert. HVAC. Im planning to go from a little wood and mostly coal to Mini and more wood for heat. The coal is cheap but dusty even though i have hot water baseboard. Ill save it for the 2 worst months of the winter. Ill have less than 1k in a 1 ton unit. Unit and Materials about $600.
What exactly are you getting?

I might get 2 or 3 at that price.
 

sportbikerider78

Minister of Fire
Jun 23, 2014
2,493
Saratoga, NY
In my last house I had a 40k BTU Mitsubishi. It was nearly silent. Amazingly quiet.
Cost about $20 per month on super hot months for a 2000sqft house with super high ceilings.
I can't recommend the enough. I had such a good experience, I'd never buy anything else.
 
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Seasoned Oak

Minister of Fire
Oct 17, 2008
7,071
Eastern Central PA
What exactly are you getting?

I might get 2 or 3 at that price.
Its called Comfort-aire . These things are notoriosly price jacked by installers. They seem to be getting , 3 or 4 times the equipment cost for a few hours work,going by some of the local pricing. Ill be paying about $50 an hour for the tech who happens to be my tenant and still come out under 1k. A Gree the same size is 1k-$1200 just for the unit not including the line kit. I may go for a higher end model down the road but , doing the numbers, im not so sure they are worth the extra cost. I have several properties id like to install these depending on how they perform. Ill give a better breakdown after the install which starts today.
 
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maple1

Minister of Fire
Sep 15, 2011
10,462
Nova Scotia
These things (in general) are really good at cheap heating, but almost ridiculous when it comes to cooling using next to no juice. So far this year we have only had ours on 'dry' (dehumidify), and the house has been super comfy. I thought someone switched to a/c the other day coming into the main room, seemed super chill, but no, still on dry. Even on a/c, a huge improvement over the window shakers.
 

Seasoned Oak

Minister of Fire
Oct 17, 2008
7,071
Eastern Central PA
Ill probably need 2 or 3 ,this a old barn is about 3000SF. And not very well insulated.
 

peakbagger

Minister of Fire
Jul 11, 2008
5,297
Northern NH
My bet is its low end mini that is not cold climate so they can make them cheap. It basically window rattler parts in a different form factor. Its the standard gamble for chinese products, roll the dice on quality control and long term performance versus generally higher reliability/durability of a name brand part.

Then again with a HVAC tech at your fingertips it may be worth it, for me getting my unit fixed is probably a $300 minimum bill just for tech to show up and all he will do is check the charge.
 

Seasoned Oak

Minister of Fire
Oct 17, 2008
7,071
Eastern Central PA
The tech has installed boatloads of these units and claims he never had a single problem or complaint yet. Gives me some unbelievable heating cost numbers from his own house that i still need to see personally to believe ,but i have no reason to doubt him actually. He used to heat with coal but is now thrilled with the performance of these minisplits. Ill probably do a Hi eff Gree for the next one just to compare.
 

peakbagger

Minister of Fire
Jul 11, 2008
5,297
Northern NH
No doubt PA is in the sweet spot for performance of a cold climate minisplit. Northern NH is definitely on the fringe but it still makes sense for me for shoulder season and occasional AC in the summer (I have been using mine during this record heat spell up north.
 

Seasoned Oak

Minister of Fire
Oct 17, 2008
7,071
Eastern Central PA
it still makes sense for me for shoulder season and occasional AC in the summer (I have been using mine during this record heat spell up north.
My GE window unit took a dump after 1 season so im now without anything on the first floor so im baking lately. Yes i want these mainly for shoulder season which is basically 50% of the time. I still have oil and wood stove to tackle the coldest winter months.
 
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Seasoned Oak

Minister of Fire
Oct 17, 2008
7,071
Eastern Central PA
I forgot about the Summer AC part so the mini is good for 75% of the time as opposed to 50% spring and fall and probably half the winter as well.
 

CaptSpiff

Feeling the Heat
Jan 13, 2014
481
Long Island, NY
Agreed ,no way would i want cool only. In pa we need both sometime in the same week. Getting one installed this week , by my tenant who is behind on his rent and is a cert. HVAC. Im planning to go from a little wood and mostly coal to Mini and more wood for heat. The coal is cheap but dusty even though i have hot water baseboard. Ill save it for the 2 worst months of the winter. Ill have less than 1k in a 1 ton unit. Unit and Materials about $600.
Wait,... you've found a mini-split for that price? Does that include the tubing and electric cable?

I was looking at a 12k btu (1 ton) no-name (Pioneer) pickup at Home Depot, and it listed a minimum operating outside temp of +5 degF, for about $950. Got a source for your's?