Finalizing Mini Split Options

[Grant F]

Any Input on sizing or units would be appreciated. I have read a bunch of the mini split threads on the forum which are great.

Looking at putting a mini in my garage/workshop. I would say heat is as important or maybe slightly more important than cool to me. But I would think based on my reading - I may still need some supplemental heat in very cold weather.

In SW PA. We get a some decent chunks of teens and twenties during the winter with usually a couple random weeks down into single and some minus temps. Summers 80's & 90's and humid normal.

Garage North exposure - 610 sq feet attached. 10' ceilings. About half of ceiling has bedroom above - other half is R30. Walls 2x6 drywall w full foam injection. 1 man door, 1 2 car wide insulated garage door.

Using several heat loss calculators I am between 12,800 and 22,000 BTUs (most detailed one about 19k). Cooling estimates generally 10-12k.

I am going to do the mini split install myself. Undecided if gonna do final prep and connect myself or get tech to do it.

I have spent waaay too much time analyzing all the brands (from low to high end Japanses) and specs. I think (trying to keep $ reasonable for a garage ie- hyper heat models too expensive) the units with the best performance specs (focusing on heat - since cooling BTUs is prob less of an issue) vs cost the options I like are:

Blueridge 18K 18 Seer, rated to 5*, at 17* 12.7 BTU rating $1,200 w/install kit.
It appears to be a rebranded Gree Neo. Specs are identical and when you
click on the submittal spec sheet for it the browser tab actually lists the
gree name and model number.

Gree Vireo 18K 20 seer, rated to -4*, at 17* 12.4 BTU rating ~$1,814 w/install kit

I am enamored with the Mr. Cool DIY either 18k 16 seer (rated to 5* / 11.3 BTU at 17*) or 24k (15.9K BTU at 17*) with the ease of precharged lines. Performance is not quite as good and you are paying a premium for the DIY - prob what it would cost to have the HVAC tech come out for final connect on one of the other units with higher performance. Was also not impressed with answers I got to tech questions from Mr Cool.

I could see Pioneer 24k 20.5 seer, rated to 5*, 15.3k BTU at 17* as an alternate option $1,228 w/install kit.

The next highest price option that had good cold weather performance was a Mitsubishi 14k that had 18k heat and rated to -4* but had slightly lower heat BTU at lower temps than the blue ridge or gree. and Price substantially more - about $2,100 w/install kit. + tools or Hvac tech. Don't think I want to get than expensive.

Should I be chasing the down to -4* rating of Gree or Mitsu - or assume that although it may heat some it wont be enough down below 5-10* ish?

Or should I go with the Blueridge - which actually has slightly better heat BTU's down to 5* than the lower temp rated Gree - save the $600 and put toward supplemental.

I would consider a larger (24k) unit for the higher heat BTUs but would think it would be way too much cooling - and cost more to operate.

I would say I am a little more comfortable with the Gree Brand and Blueridge assuming it is a Gree product than more off brand like Mr cool or pioneer. May be unfounded though!

Any thoughts or suggestions appreciated. Anything I am overlooking?

 

[pcampbell]

You might look into Fujitsu 15RLS3. I believe they are the most efficient and cheaper than Mitsubishi.

http://www.fujitsugeneral.com/us/products/split/wall/index.html

 

[Grant F]

Thank you for the suggestion.

It was on my list of contenders (which has 22 units on it) - unless I can't find the right online vendor that Fujitisu was about $75 than the Mitsu with almost identical specs/performance ratings.

I did find it odd that most threads I have read stated Fujitsu is cheaper than Mitsu but I found them priced very similarly in my digging.

 

[mike93lx]

They are inverters, right? So it should throttle down cooling when it isn't needed, which i would expect makes the bigger units less of a problem.

 

[pgray007]

I have a Daikin that I love. Sips electricity... I did the install and found a retired HVAC guy on Craigslist who connected the lines, pulled vacuum, etc for like $300. Well worth it for the assurance it was done right and less than the cost of tools I’d probably never use again. There’s pics and some text about the process in my build thread, and it’s done fine through SC summer and the crazy teens we’re getting this winter.


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[Grant F]

They are inverters. Which I understand is less of an issue in over sizing because they throttle back.

I read some information on sizing mini splits that did say if they are significantly oversized it can still result in short cycling and premature wear/shorter life on a unit.

In my AC scenario I would guess 24k is double what I need. Don't know if that is considered too oversized or if it would really be a wear concern.

I would probably use the AC side more sporadically and less hours than the heat side which may also make this concern of wear less an issue.

Appreciate everyone's experiences / insight. I have read many great threads about many things on garagejournal for years just never joined in.

 

[mike93lx]

Any need for cooling elsewhere? Might be a good opportunity to add another 12k condensor somewhere else to justify the bigger compressor for heating

 

[Grant F]

No need for AC elsewhere.

 

[PoorOwner]

You will probably want to slightly oversize it at the most. So 18K is more than fine. They usually put more than 18K in heat mode anyway.

And yes, even with the inverter they can short cycle on and off. Most of the time they run at full capacity just to get to with 2-3 degrees of where you set it, that's where it would start slowing the compressor. Once the AC turns off, as any other AC, it doesn't feel as good in cooling and heating mode, so you want to maximize the run time.

I would even think a 12 or 15k is ok with insulation, as long as it has the low temp heating capacity that you need.

The regular mitsubishi line will cut out at -9 and only turn back on at -4. So you can assume in the negatives it won't work too well at all, the H2i (hyperheat) cuts out at -18 and turns back on at -14.

 

[theoldwizard1]

Price is not the only thing to consider. Can you get some of these less popular units serviced ? Cam they get parts reasonably quick ? (LG and Samsung home appliances are notoriously bad on parts availability.)

Mitsubishi and Fujitsu are #1 and #2 (or #2 and #1) in most parts of the country.

 

[Retlaw 66]

Do you have a Johnstone HVAC supply near you? (There are some near Pittsburgh.) I bought a 12k Fuji with hyper heat (12RLS3HY) for under $1600. It's $1995 online from eComfort, so I got a very significant discount. They also carry Daikin, another top-rated brand.

My first choice was a Mitsubishi, but the Fuji price and the fact that most suppliers around here sell/service the Fuji was a factor. I believe the heating performance was better on the Fuji than the Mits.

The lineset was a disappointment. The flares weren't well done, so I redid those myself and did a much better job. Got the 4 wire cable from Supplyhouse.com, Line covers and mounting brackets on Amazon. Next time I'll just use downspout/gutters and make the brackets from Uni-strut, both avail from Home Depot.

Check with your electric company, they may offer a rebate. PECO gave me $175. Also consider a new credit card that will give you a bonus if you make a sizeable purchase.... I got $200 after spending $2,000.

I did the install myself. Spent under $500 for all the tools/equip. I may install more units in the future, so the tool cost should be a good investment.

BTW, this unit was for my house, LR-DR-Kit, hence the additional $$ for the hyper heat. For a garage, you can skip the hyper and use a back-up for those few days it gets REAL cold.

 

[terabitdan]

What inside garage temperature did they use to calculate the manual J? What do you use to heat the rest of the house?

The issue is, if you size the mini split based on the manual J for heating, the A/C will be oversized and less able to control humidity in the summer.

The mini splits support a range of cooling, the 12k might be 4,000-13,000 BTUh while an 18k might be 4,500-18,000.

Bottom line, you’d probably have the best year round comfort and performance with about a 15k unit. Then plan on either letting the garage temp drop when it’s really cold outside or use supplemental heat for those days.

If you have natural gas available it will almost certainly be the lowest operating cost but you’ll probably never get payback on the install costs. electric is probably the best balance of upfront to operating cost for supplemental use.


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[Grant F]

Retlaw Thanks for the ideas. Does Johnstone sell units to the public? There is one near me. I have been meaning to double check the rebate.


terabitdan I have used 68 and 70 as indoor temp numbers. Rest of house is natural gas - I think getting supply to the right spot in the garage would be some work for a plumber. Thanks

 

[Jackfre]

I believe your 18 & 24 sizes are to large. That referenced Fujitsu 15 RLS3 would be more than enough for the size and build quality you have there. TOW1 is also giving you some good info on this as to the "flash in the pan" lines that are out there. Over the years I have seen so many lines come and go. Even Daikin pulled out of the US market...twice. There are plenty of line that work well. Mitsu and Fujitsu are 1-2 for a reason. In your neck of the woods, I'd try to buy from RE Michel.

 

[JakeKohl]

18k should be fine. I have a 24x36 with 10' ceilings that I heat and cool with an LG 18kbtu mini split at 24seer. My garage has a full second story (also heated and cool with another 18kBTU LG unit) over top of it. My walls are standard 2x4 stud walls with decent insulation. I have a 16' insulated Overhead Co garage doors on one end and a 12' door on the other. It's been in the teens here for the last couple of weeks and that unit can keep the garage (and a poorly insulated 16x12 storage room that opens into it) at 70 degrees with no problem.

That said, I'm not in PA (I'm in upper South Carolina). My load calcs indicated that 12kbtu would be plenty but an insulation guy out to give me a quote scared me that they were too small - so I sold those and upsized them. The 12kbtu probably would have been fine - but, regardless, the 18k sure turn the temps around in the garage fast and I'm glad I upsized them. If it's 40 degrees outside and 50 inside, I can turn it on and be at 68 in about 10 minutes.

My LG units have been running for almost four years - the little stepper motors that drive the left and right swinging action went out in one of them (a $20 part but about 2 hours to get to and replace) and something's not working right with the vertical swinging part in my other one - but it's not really affecting anything so I've left it. The blowers on the indoor units have gradually gone from barely audible to making a noticeable whirring sound but the compressor/outdoor units have been flawless and are incredibly quiet. I'm still very happy with them.

 

[Retlaw 66]

... Does Johnstone sell units to the public?....

.....I'd try to buy from RE Michel.

My local Johnstone would sell to me, RE Michel would not. It likely varies from store to store.
I told them I have EPA cert (I do), but they never asked for proof.

 

[Grant F]

What is the general opinion of Gree? Do they fall into the flash in pan company/unit - I have read they are the largest AC manufacturer in the world?

I also don't doubt how good Mitsu and Fujitsu are. My dad has several Mintsus (maybe 5 of them - prob 3 compressors) in his 1900's house. The oldest one probably 10-15 years old with no issues.

In my case, Being a unit for the garage vs in my house - I am trying to determine where in the $1,000+ price swing to be. I could prob buy 2 Blueridge (Gree) for the price of one Mitsuu/fujitsu or the better performance rated actual Gree for somewhere in the middle.

But having a workhorse with history and likely people familiar with servicing them obviously has value down the road.

 

[justinjoyal]

What is the general opinion of Gree? Do they fall into the flash in pan company/unit - I have read they are the largest AC manufacturer in the world?

I also don't doubt how good Mitsu and Fujitsu are. My dad has several Mintsus (maybe 5 of them - prob 3 compressors) in his 1900's house. The oldest one probably 10-15 years old with no issues.

In my case, Being a unit for the garage vs in my house - I am trying to determine where in the $1,000+ price swing to be. I could prob buy 2 Blueridge (Gree) for the price of one Mitsuu/fujitsu or the better performance rated actual Gree for somewhere in the middle.

But having a workhorse with history and likely people familiar with servicing them obviously has value down the road.

I’ve said it before and will say it again, I trust Gree just as much as I trust Mitsubishi or Fujitsu.

I have installed many many Gree mini-splits with VERY few problems. Great performance, competitive pricing, good warranty (we get a better warranty here in QC.)

Look into the Gree Crown. See how much you can get one for. A 12k unit actually puts out ~13k in cooling mode and ~18k in heating mode, which would apparently be just what you need, plus it will provide GREAT heat output down to -22F, so you’d be covered year around.

 

[Grant F]

Anyone have experience good or bad with theacoutlet.com ? The are cheapest by about $100.

Seems like all the online mini split retailers have their share of bad reviews - acwholesalers and goductless (same company) seem to have the most. I saw a handful of positive comments about ecomfort on this forum.

Ingrams doesn't sell the units I am leaning toward.

 

[mike93lx]

Anyone have experience good or bad with theacoutlet.com ? The are cheapest by about $100.

Seems like all the online mini split retailers have their share of bad reviews - acwholesalers and goductless (same company) seem to have the most. I saw a handful of positive comments about ecomfort on this forum.

Ingrams doesn't sell the units I am leaning toward.

No experience with them, but i bought my Friedrich mini split through ajmadison.com

Great price and quick shipping

 

[Black Oak]

I have always found justinroyal to be on point and convincing. Gree has been a winner for him, and I think he always seems to make sense. Somebody who has "in the trade" advice is nice.

 

[Grant F]

Just wanted to post an update and again thank everyone who replied to my original post.

I pretty much made a decision back in January but wanted to get into better weather to work on the install and not have the unit sitting a couple months. I also had a ski trip in February and did not want my wife to have to deal with a somewhat unpredictable freight delivery while I was away.

In the meantime I started acquiring some of the parts and pieces I would need for the project. One thing I found interesting is that alot of the wall brackets for minis don't get the unit out very far from the wall as far as manufacture specs for clearance/airflow (i will note that I think fijitsu or mitsu had smaller clearances but many want 12" behind the unit). I ended up getting a Quicksling bracket that will get it close to 12" out.

Anyway. I went with the Gree Vireo 18k unit. It does 19.7k heat and 18k cool and heats runs down to -4. It also has a freeze guard mode that allows a low inside heat setting of 46 degrees (many of the less expensive minis low temp is around 60) nice to keep a minimum temp when not in the garage/shop. I think I got a pretty good deal on the unit and the wait paid off in that department. I saved just under $300 versus the prices two months ago. It arrived today.

I got it from acwholesalers.com - my mini review of them is as follows: when I ordered it listed as in stock ships in 2-3 days. After 1 week it still showed as order received by warehouse. I called and was advised part of the unit was on back order (customer service was helpful/friendly) and given an expected ship date. It ended up shipping early from the date customer service gave me - so arriving today it took 2 weeks and day. I paid extra for the lift gate service, just to prevent any possible issues. The truck that delivered did not have a lift gate. The driver took off the pallet and helped get it in the garage. He said his paperwork showed nothing about a lift gate.

I will update how things go with the install - hopefully smoothly. I am planning on getting an HVAC tech to do the nitrogen test, vac, and final release.

 

[Jackfre]

Good call on having someone do the final hook-up and charging. You put a lot of work into this. Good luck with the system and let us know how it works out for you. I am surprised that Johnstone would sell and that RE Michel would not. My experience around the country is exactly the opposite.

 

[Grant F]

I am trying to figure out exactly where I want the indoor head.

Does anyone have recommendations on a good height to mount the unit?

I plan using at least as much for heat as AC.
Google research has found "at least 8-10 feet from floor," "6 feet from floor," 7 feet from floor"

I have 10 foot ceilings in garage. Was thinking bottom of unit at 7 1/2 feet? Any reason 7' or 8' would be better or make much difference?

Thanks

 

[PoorOwner]

I have the bottom at 86" and 3 feet above the top of the unit and it works the best that way. The temperature is dead on accurate in heat and cool.

When I had units mounted 4" from the ceiling the heating mode works poorly because it would **** in it's heat and shut off too soon, it's a common problem with these units in heat mode - unless an external thermostat is used to sense temperature.

 

[Grant F]

Ok guys, looking for some experienced guidance/advise. It has taken me awhile to get this thing to the point of releasing the charge - bad weather, kids, other projects moving to priority etc.

I had the HVAC company that has done work at my house for the past 8 years come out to do a nitrogen pressure test and vacuum. Short story -they said they have worked on and installed minis but they didn't have a mini split adapter and didn't have a micron gauge so we parted ways.

I decided to pull the tools together and do it myself. So..

I put a nitrogen charge on last night and noticed an audible leak on the low side connection at the unit. (I did not use any factory flares - as many recommended - I did all new flares w yellow jacket concentric flare tool - and used torque wrenches when making connections - also used nylog on all) I took the fitting apart made sure it was lined up and re-tightened. Put a 200lb nitrogen charge on and it held - gauge did not move at all - for 16 hrs overnight.

This afternoon I Started monkeying around with cleaning up the line set insulation further up the wall and over the course of maybe an hour I noticed the gauge dropped 2-3 PSI. I rechecked with bubbles and was getting a slow bubble at same low side fitting.

I took it apart, cut (I did note on the old flare a scratch that ran in to out on the flare - looked like maybe I scratched it when duburring), I deburred with a different style tool, reflared, inspected the flare closely with a flashlight, and reconnected torqued to almost top of recommended range. Put on 200 PSI nitrogen and initially saw two or three bubbles grow and pop in the same location it was before (on the bottom of the flare nut/threaded side). I broke and had lunch - after about 45 minutes or so I rechecked with bubbles and got no bubbles. I jiggled the line set, tapped on the connection and pipe with a wrench, shook the condenser some, heated the connection with a hair dryer for 10 minutes, poured ice cold water on it. In between i kept checking with bubbles and nothing - and the pressure held. I finally bumped the Nitrogen up to 225 PSI and repeated some of the antics and bubble checked - nothing. The Nitrogen gauge has not moved in like 4 hours.

I don't know what to think. I did not tighten at all after I saw those last couple bubbles but now after all the antics can't get any bubbles and the pressure has held. Is it possible that leak test liquid pushed air from the top of the flare fitting down through the threads and pushed it out at the bottom of the fitting making it look like a leak? If it was nitrogen leaking I would not think it self healed.

Any suggestions would be appreciated.

Should I pull a vacuum and see if the microns hold and think I am good. Should I do that and then do another nitrogen pressure test and vacuum and assume I am good. Or should I take some other approach?

Thanks

 

[moreover]

Is it safe to assume you checked the receiving end of the flare in question for imperfections? I was going to save some money and skip the pressure test but bought the HP regulator tonight. I want no issues during my install or else things get more involved with a possible evacuation/weigh in.

I'm about to do my first install soon and am interested in the replies

 

[PoorOwner]

It could be the nylog overtime moved and covered up a scratch or whatever it was.

At this point I agree taking apart and check the brass side on the condenser. I have seen hair like shavings from machining around the fitting. And check that it is obviously not dented or scratched.

 

[justinjoyal]

Honestly, before I’d start taking stuff apart, knowing the flare is good, I’d skip the torque wrench and tighten up that connection some more.

I have never used a torque wrench on my flares and never had problems. 1/4 and 3/8 lines can be overtightened to the point where they will come apart (I’ve done this intentionnaly), but to mess up a 1/2 and over flare would require some serious strenght!

Pressure check with more psi (~300). If all is good vacuum down to 500 microns or less and release.

 

[Grant F]

I did look at the receiving flare before I put it back together. Maybe not super close inspection but it looked ok to me.

It is a 5/8 line - I think the recommended torque was 68 to 82 n. I set at 80 this last time. Is there any chance of creating a leak by overtightening.

Justinroyal I know you are a gree guy. The manual recommends nitro to 200 so I was a little cautious pushing to 225. I had read in general you need to be careful not to go to heavy on the pressure because the valves can leak and contaminate the Freon? I am guessing not much concern at 300?

Also just an update the pressure held overnight - about 16 hours. Dropped maybe 1/2 of a psi but temp went from mid 70s to low 60s overnight.

Thanks guys

 

[PoorOwner]

300 should be safe considering the valves hold the Freon shut at the resting pressure around 150 and a bit more. You are not putting too much differential through the gates. My thought anyway. But never have a manufacturer recommend holding a pressure for extended period. Usually 1/2 hour.

 

[justinjoyal]

I did look at the receiving flare before I put it back together. Maybe not super close inspection but it looked ok to me.

It is a 5/8 line - I think the recommended torque was 68 to 82 n. I set at 80 this last time. Is there any chance of creating a leak by overtightening.

Justinroyal I know you are a gree guy. The manual recommends nitro to 200 so I was a little cautious pushing to 225. I had read in general you need to be careful not to go to heavy on the pressure because the valves can leak and contaminate the Freon? I am guessing not much concern at 300?

Also just an update the pressure held overnight - about 16 hours. Dropped maybe 1/2 of a psi but temp went from mid 70s to low 60s overnight.

Thanks guys

Should be good to go.

I suggest using Nylog on the two valve caps + service port cap to avoid leaks.

 

[eddieK]

i’ve said it before and will say it again, i trust gree just as much as i trust mitsubishi or fujitsu.

I have installed many many gree mini-splits with very few problems. Great performance, competitive pricing, good warranty (we get a better warranty here in qc.)

look into the gree crown. See how much you can get one for. A 12k unit actually puts out ~13k in cooling mode and ~18k in heating mode, which would apparently be just what you need, plus it will provide great heat output down to -22f, so you’d be covered year around.

^^^^^ this ^^^^^