how well does a mini split AC/heat hold up in garage ? - Page 3

rfuerst911sc · 01-10-2015, 01:04 PM

Hey guys I'm still getting quotes. Today received a quote from the local HVAC company that installs for Home Depot. He came up with a suggestion to install a 2 ton single head unit and install it on the sidewall of the 24 x 26 so it blows towards the single bay. He said with the size of the two windows in that dividing wall if left open will allow good air movement. So going with a single head helps a lot on the cost. So for them to install a Trane system ( made by Gree ) it is $3800.00 for a 16 SEER and $4800.00 for 18 SEER. I provide the 220v electric which I can do.
But Gree is made in China but is supposedly better quality than some.
On the other hand I can buy outright a 22,500 btu Mitsubishi single head with 15 ' line set for around $2300.00 and install it myself. However if the unit isn't " installed " by a licensed HVAC contractor the 5 year parts/7 year compressor warrant is void. It looks like all companies do this with their warranties. But the Mitsu is supposed to be top quality. Basically the same price for Fujitsu. The way I look at it the money I save by doing it myself will pay to have my roll up uninsulated garage doors replaced with insulated panel doors. What do you think guys ?

fireant911 · 01-10-2015, 02:03 PM

rfuerst911sc,
I feel your pain as I went through this last year. Given my situation, I was given a plethora of different options regarding the sizing from many different sources. These differing opinions initially caused me 'paralysis by analysis' until I realized that I had to do something. I stuck with my gut and went with a Fujitsu dual zone mini-split (I did my homework well and researched considerably). Just as a note: yesterday, when the temperature here was 20 degrees, I turned on the mini-split to economy mode (set at 50 degrees) and saw/felt the temperature rise quickly. As a side note, I did a similar test in the summer when it was +90 degrees and these dual units brought the temperatures down quickly. We have never seen an appreciable increase in our power bill since these units were installed (we do record all bills in a folder).

Our garage doors are not insulated and the temperature difference between outside/inside is notably different (I will get some readings in the morning if you are interested).

We did have a certified HVAC tech install our units therefore our warranty is valid (although we purchased from an online source - EComfort). Again, I feel your pain and frustration...

rfuerst911sc · 01-10-2015, 02:15 PM

Quote:

Originally Posted by fireant911

rfuerst911sc,
I feel your pain as I went through this last year. Given my situation, I was given a plethora of different options regarding the sizing from many different sources. These differing opinions initially caused me 'paralysis by analysis' until I realized that I had to do something. I stuck with my gut and went with a Fujitsu dual zone mini-split (I did my homework well and researched considerably). Just as a note: yesterday, when the temperature here was 20 degrees, I turned on the mini-split to economy mode (set at 50 degrees) and saw/felt the temperature rise quickly. As a side note, I did a similar test in the summer when it was +90 degrees and these dual units brought the temperatures down quickly. We have never seen an appreciable increase in our power bill since these units were installed (we do record all bills in a folder).

Our garage doors are not insulated and the temperature difference between outside/inside is notably different (I will get some readings in the morning if you are interested).

We did have a certified HVAC tech install our units therefore our warranty is valid (although we purchased from an online source - EComfort). Again, I feel your pain and frustration...

Daryl I would love that temp info from you as your weather conditions in Alabama are the same here in Georgia. What size Fuji did you go with and what square footage are you conditioning ? What is your wall/ceiling insulation ?
I tend to over analyze everything it is my German heritage

.

fireant911 · 01-10-2015, 04:31 PM

rfuerst911sc,
We installed an 18K Fujitsu condenser with two 9K wall mounted units. Prior to the installation of these units, we had some really good insulation put up (which is probably the biggest contributor to our success). Although spray foam insulation is superior, the cost was absolutely crazy (our neighbor is involved with this business and his 'special' price to us far exceeded all the other costs of normal insulation we received)... thus we opted for normal insulation. Heck, even the degree of the 'normal 'insulation' varied greatly (to the same amount of variation of the sizing estimations we received! - again, that was maddening). One local company actually did our insulation and it included massive insulation on all the walls and ceiling, the installation of radiant barrier shielding on the roof structure, as well as baffles along the entire roof section to direct the hot air up and away. The uninsulated garage doors (three are installed) contribute a minimum to the square footage of the garage/shop/man-cave (480'/480'/400' respectively).

We are ONLY heating/cooling the upstairs portion (man-cave) though the downstairs garage and shop are definitely benefiting from the Fujitsu's.

David · David's Garage

The Mitsubishi units are running reliably all over the world. Buy one and install yourself.

fireant911 · 01-11-2015, 06:09 AM

Quote:

I will always vote for two smaller evaps over a single large unit. I think it balances the air flow better. As well, you will frequently find that the space can be handled by one of those smaller units. Also, in checking the specs on my Fujitsu literature the 24 is 18 seer. The 12's are 25. Redundancy is also good in the event that one unit fails.

I borrowed the response above from the GarageJournal forum and it really helped me with part of my decision. Unlike conventional HVAC systems where over-sizing a unit is a huge no-no, most, if not all mini-splits are inverter driven which means they will run at a (variable) speed needed based on the current conditions of the space. In regards to moving air, our Fujitsu's have louvers that move to direct air throughout the space.

There is a wealth of data available for each mini-split system/configuration which only made things harder for me... too much information. Given that our system is installed and fully operational, I would have to vouch that a dual zone system would be a very good option for your application.

fireant911 · 01-11-2015, 06:28 AM

Another worthwhile read (Are You Making These Mistakes with Your Garage?) - especially some of the feedback.

rfuerst911sc · 01-12-2015, 04:14 PM

I think I have found the unit I'm going with. Excellent brand/quality, very good SEER rating and it's the best price I have found with free shipping. What do you think ?

Mitsubishi MZ-HE24NA M-Series - 24,000 BTU - Ductless Heat Pump System - Wall Mounted - 18 SEER - 8.5 HSPF

VincentVega · 01-12-2015, 08:34 PM

Quote:

will pay to have my roll up uninsulated garage doors replaced with insulated panel doors. What do you think guys ?

I put rigid foam in my steel doors and it works great. I'm cool with the metal side exposed but you can easily cover with vinyl or whatever floats your boat.

rfuerst911sc · 01-13-2015, 02:26 AM

Quote:

Originally Posted by VincentVega

I put rigid foam in my steel doors and it works great. I'm cool with the metal side exposed but you can easily cover with vinyl or whatever floats your boat.

The doors i currently have are commercial roll up doors so i can't insulate them. But i plan on replacing them with standard panel style. If buying the insulated panel doors is too expensive then i will insulate them myself as you described. I had a insulated panel door installed on the garage under the house and the insulation is just white styrofoam with a protective vinyl skin on it.

Scuba Steve · 01-13-2015, 02:49 AM

How exactly are A/C units sized for a garage? I may be in the position to basically get a "free" system at some point in the future.

Three years ago I installed a new heat pump in the house with the roofing accident. The air handler will almost certainly be damaged but to an unknown extent and the system is presumed by everyone to basically be toast. However, if it is still functional I was thinking maybe I could use it for the garage? I don't know the specs offhand but it was set up for a 95 year old, 1,500sq ft house. Our garage is about 1,000 sq ft with a high ceiling and it was already going to get insulated and rewired soon anyway... Think it might work?

JJ 911SC · JJ 911SC's Garage

Quote:

Originally Posted by Scuba Steve

...Think it might work?

Should and probably more efficient as it only one big space.

fireant911 · 01-16-2015, 04:26 AM

Quote:

Originally Posted by rfuerst911sc

Daryl I would love that temp info from you as your weather conditions in Alabama are the same here in Georgia. What size Fuji did you go with and what square footage are you conditioning ? What is your wall/ceiling insulation ?
I tend to over analyze everything it is my German heritage

.

rfuerst911sc,
I owe you some garage temperatures! Our scenario: garage upstairs is heated and cooled with a mini-split (and a gas fireplace for ambiance). I was last up there yesterday afternoon at 3:00 PM. When I left, I turned everything off even the pilot light. The garage had one vehicle in it that was last parked at 9:45 yesterday morning. The garage is connected to our laundry room (currently unheated) which is connected to our sunroom (also currently unheated). Here are the inside garage temperature and outside temperatures as recorded this morning at 6:30 AM - garage temperature 48.2 F and outside temperature of 32.2 F.

I included info earlier about the size of the mini split (dual zone 9K wall mount / 18 K outside condenser) as well as the insulation details. Out garage doors are not insulated (which is why I am providing the inside/outside temps for you). During the design /build phase of our garage I spoke with the builders and insulation crews and they did not get overly 'warm' about recommending insulation of garage doors... at least not at this part of the south. The garage doors themselves will never be snug fitting and air gaps, to varying 'degrees', will always be present.

All this is being said to simply state that our garage stays noticeably warmer than the outside without using any garage door insulation, however; we did not skimp on insulating the walls, overhead, and roofing (radiant barriers, baffles, and insulation)!

MBAtarga · 01-17-2015, 05:52 AM

spammer xghduh reported

rfuerst911sc · 01-17-2015, 06:10 AM

Unless something drastic happens I'm going to order the Mitsubishi 2 ton mini split next week. I've done enough research it's time to spend some cash ! Regarding insulated garage doors, mine face the hot sun to the West. In the late afternoon you can stand 2 ' from the roll up doors and just feel the heat. The garage under my house also faces to the West. Last year I had a insulated garage door installed it is a HUGE difference. Boiling hot out if you touch the insulated panels you feel zero heat but touch the exposed metal framework or the hinges you feel it there ! I do think buying insulated doors vs. uninsulated and insulating yourself will save some $$$. It's going to take me a while to install the mini split, the radiant foil barrier to the roof, then the sheetrock, then the insulation and finally the garage doors but at least I have a plan.

rfuerst911sc · 01-23-2015, 01:00 PM

I pulled the trigger today and ordered the 2 ton Mitsubishi mini split from EComfort. Nice people to deal with. And saved a bunch over the local yahoos

. Two ton mini split, 15 ' installation kit complete with everything needed to install, 14 ' of exterior vinyl two part wire/hose chase with all the fittings needed, wall bracket all delivered to my door for $2403.05 ! It's still a lot of money but compared to the local quotes aprox. $4,000.00 less. Of course I still have installation but I'm going to rough install everything and have a pro do the hook ups and pull a vacumn. I can't imagine it would be much more than $500.00 so still a HUGE savings. Thanks to everyone that provided feedback.

rfuerst911sc · 01-30-2015, 06:49 AM

Today I received the mini split, I got lucky this was an off Friday for me so didn't have to burn a vacation day to receive it. I must say EComfort.com appears to be the the Pelican Parts of the HVAC industry. Excellent feedback/communication from the day I ordered all the way up to delivery. They even sent a photo of my stuff shrink wrapped to a pallet showing its condition when it left their facility. In my case the carrier was R&L Carriers and they were top notch. Tracking was accurate and they called the day before to set delivery. Had a power liftgate and pallet jack the driver rolled it all into my garage. He stayed there as I cut open each box to take inventory and check for physical damage. The entire experience could not have gone better. Now I have to install the darn thing !

ShakinJoe · 01-30-2015, 07:57 AM

The difference is that Pelican includes Warranty. You may not have Warranty with the product purchased online!!

fireant911 · 01-30-2015, 08:05 AM

I had an equally well experience with EComfort - great prices, great selection, and great communication. I was initially concerned about losing the warranty by purchasing on line but EComfort does warranty these on-line purchases (same as manufacturer's warranty). The cost difference from buying from an authorized dealer versus purchasing the identical units online was absolutely INSANE!

ShakinJoe · 01-30-2015, 08:33 AM

WRONG. Go read the cute disclaimer on the website..."If professionally installed and registered by licensed contractor" I am in this business so I know (and I don't know much!)

These units are installed by people that range from completely incompetent to pretty darn good mechanics. But...even when you get into the "pretty darn good mechanics" area many if not most are not all that good with a residential AC system or even have the tools to install. This is very high pressure R410a refrigerant in this system unlike automotive which is all or mostly low pressure 134a. These units are not charged to superheat but by weighing in refrigerant at 0.20 ounces per foot of lineset.

Trust me when I tell you, you do not have a warranty if you put it in yourself.