DIY mini-split system

[KLF]

I'm in the final stages of renovating our camp on the lake, it's actually an old 40' long travel trailer from the 50's that now has full 2x4 walls, a rafter roof, loft, and real windows and sliding doors. The old original oil furnace was pretty scary, so out it came, which exposed rotted and oil soaked floor underneath.

This will be a 3 season usage, I can't leave the pipes full of water in the winter, power is too unreliable. We love the mini splits we have at home, and since I have capacity in the panel, that is the obvious choice here too. Got a price from a local installer of $4500 for a 15000 btu unit, which is hard to justify for occasional use. Wondering about the MrCool units that are out now, certainly within my skill set. Could do an 18000 btu unit for about $1500.

https://www.amazon.com/MRCOOL-SEER-...e=UTF8&qid=1529852001&sr=8-4&keywords=mr+cool

Anybody installed one of these? The reviews are generally very positive.

 

[1911]

Anybody installed one of these? The reviews are generally very positive.

No, but thanks for pointing them out to me. We have plans to put mini-splits in parts of the house we are building, for zoned A/C, and I didn't know there was an economical DIY alternative.

 

[LS1FJ40]

I actually know a couple of people that have them. They use them for their finished attic space where they have a spare bedroom or office. Both already had forced air furnace/ac but the finished attic space would be hot in the summer/cold in the winter.

In my experience, mini splits work well in this kind of setup where they are not being asked to hear from 0 degrees to 74 but rather from 40-74 or similar with cooling.

 

[KLF]

Yes, they do have a limited operating range. We had a 2-head Fujitsu system installed in our house last year, primarily for AC, which it worked very well for and actually used less energy than I expected. I ran them most of the winter to supplement the oil boiler, and I think they significantly lowered the oil usage. But they couldn't keep up when we had a couple of really cold snaps below zero.

Mostly wondering if anybody here has an experience with the MrCool units and doing a DIY install.

 

[davegonz]

I have been looking at these a while now. I really like the pre-charged line sets that make it easy to install with minimal tools. I still need to insulate the heck out of my shop before I do this though.

 

[PAToyota]

What led you to the MrCool unit? Just curious as I see there are a number of brands available. My concern with "off" brands is availability of parts or service options - leading to it being a throw-away item if anything goes wrong.

 

[davegonz]

Price and reviews.

 

[KLF]

I am interested in the MrCool since they are sold at the local Home Depot and Lowes, as packages. If there is any sort of a problem, they will take them back. I'm not interested in buying something off the web (Amazon or other), due to the reasons you mention.

I'm sure if I call the contractor that did my Fujitsu systems last year they will tell me the MrCool packages are crap. Obviously I like to buy quality, but it bothers me that the only way you can get any sort of warranty with the Fujitsu/Mitsubishi units is if they are installed by an approved contractor. This install at my camp is super simple, and it a very occasional use, so it's hard to justify the high labor charge.

 

[PAToyota]

Perhaps ask the contractor what you can do to prepare for the installation to lower the cost? If everything is plug and play, he'll likely appreciate that. Obviously, you're not going to get down to the MrCool price, though.

 

[AJP]

Well I watched my mini splits installed and while I dont know what I dont know... each unit got its own circuit off one of my power panels with conduit carrying the power to the outside compresssor unit . The conduit terminates in a wall mounted box with a breaker - then fed to the compressor. The interior 'head' must be mounted (securely) in accordance with the template provided which is supposed to provide the necessary slope to the head to ensure condensation drains outside. As well the outside compressors (at my farm - which has fairly mild winters by Canadian standards) are mounted on stands which in turn are set on concrete pads. At the cottage (east side of Lake Superior) the compressors are mounted on pretty sturdy wall ('L') brackets which are about 5 feet off the ground to accomodate drifting snow. All the units (4 so far) have the pan heaters to prevent freezeup. The 'factory trained' (as claimed by the contractors) prefer to keep the line sets as short as possible and so far that hasnt been a problem .... Although the second floor at the farm will be a challenge when we get around to it. I have used Mitsubishi 'hyper heat' pumps and so far no complaints .... they have reduced winter electricity bills for heating (with a monitron boiler) at the cottage from the $500 - 595/mo. to $200-300/mo and thats with the monitron providing the backup heat. We have oil at the farm and I havent got exact comparable data yet .... but there is certainly a savings withe heat pumps!