Garage Heat/AC Mini Split - Exterior Aesthetic Concerns!

[polizei1]

Alright so I'm building a new house and thought I was 100% convinced to run a Reznor gas heater in the garage. The more I look at mini splits, especially after Matt Moreman (Obsessed Garage) posted his video, the more I've been thinking about one.

If it's possible to have both heat and AC coming from the same mini split, surely that would be ideal! The problem I'm having initially is trying to work it into my plans, mainly being that my garage will be a rectangle. Has anyone here ran a mini split in their garage (~750sq) and had success with both heat and AC? What about the aesthetics from the exterior? Anyway to hide the lines?

Here's what I'm thinking...place the condenser in the front and hide it by bushes, run a cover up the wall and paint it to match the trim (stone and Hardie board). How would this look? Anyone done this before, if so what was the result?

Just trying to gather ideas...I want to make the best decision, and would love to have AC, but if it compromises the look of the house it's not worth it! I would only run heat/AC when I would be actively using the garage, so the unit definitely would not run all the time, hardly ever at times. BTW: Yes my Sketchup skills ****!

 

[Jinks]

Yes, covers work well. Some have even used rain gutter down spouts as a cover. I opted to run the lines down the wall inside my garage & come out down near the compressor. Either works.

 

[polizei1]

Awesome, thanks. Can the lines be ran through the interior 2x4's, or would they have to be exposed on the interior wall?

I'm also concerned with being able to actually heat in cold temps, considering the compressor is on the exterior. I may be better off just doing a cooling-only mini split and the Reznor. Hrmm..

 

[Falcon67]

LOL, when it's 100 in the shade here we don't give a crp what the AC unit looks like as long as it works.

Any of the heat pump units should provide both AC and heat. They just reverse function depending on what you want.

I would beware putting it too tight to bushes as anything that compromises air flow will hurt efficiency. Also you may need access for service. People typically don't put anything anywhere close to the outdoor units here. If you are that worried about aesthetics, put it behind the building. It's one thing to hide the lines creatively - it's another later when you rip all that out to service or replace. We ran our heat pump lines right up the wall from the condenser unit into the attic, shortest path. A gray sheet metal cover hides the lines. It's non-obvious and if we weren't brick it could be painted to match the trim.

Awesome, thanks. Can the lines be ran through the interior 2x4's, or would they have to be exposed on the interior wall? I'm also concerned with being able to actually heat in cold temps...

You can run them any way you like. Should be wrapped and insulated. Heat pumps work down into the 20s - at some point they would kick on an aux heat strip on the inside, same as an electric heater. Depends on your climate. We run all winter with heat and never engage the backup.

 

[polizei1]

Yea I'm in Ohio, temps get into the negatives. Sounds like I may be better off sticking with the Reznor for heat and getting a separate cooling mini split.

 

[PoorOwner]

I am going to be running most of the line in the interior wall of my garage because I think it is quite ugly. it's only going out of the exterior wall a couple feet to connect to the condenser. In the garage I can easily tolerate it, a section of it is going to my storage room so I don't really mind. I have to keep a slope to make sure the condensate drain by gravity.

I love the look of the mini split interior unit without lines inside coming out of it. But what I don't like more is the lineset covers outside the siding /stucco of the house. Especially when it is sideways it doesn't even look like a gutter.

The lineset itself is insulated. The manual say under high humidity they can condensate a bit. I personally have not seen this, but it is something to keep an eye out for. the interior space where the lineset is, should have low humidity given the system is dehumidifying the space.

 

[polizei1]

Thanks, appreciate the insight.

 

[Jinks]

Awesome, thanks. Can the lines be ran through the interior 2x4's, or would they have to be exposed on the interior wall?

I'm also concerned with being able to actually heat in cold temps, considering the compressor is on the exterior. I may be better off just doing a cooling-only mini split and the Reznor. Hrmm..

They can be run inside the wall if you want, but keep in mind access to them if you need to do any maintenance. I haven't had any problems, but mine are exposed inside the garage. If I wanted them covered I'd make the cover removable. Also, in your temp. zone I'd go straight cooling, & use a separate heat source. Let us know how it works out.

 

[Marctrees]

Like Falcon sed - Just make sure if you shield from view the outside unit w bushes, a fence of sorts, whatever, not to impede air flow.

And keep in mind service access.

Don't want to piss off the Tech with 90 degree heat kneeling in the sun fighting a bush.

Won't reduce yer bill at all.

Quickly removable like lift up and out or something similar air passing homemade fence panels are a solution.

Or just a FEW...and OBVIOUS screws maybe, that's what we did. Marc

 

[EdT]

I ran my lines inside a standard 2x4 wall. Seems to work fine after 7 years. Mine has no specific access panel for the lines, but it wouldn't be difficult to do. I decided that it was worth the risk to cover them up. Lots of the AC lines in my house are buried w/o problems after 30 years. I know where they are and sheet rock is easy to cut should the need arise
AFA heating goes, I live in Georgia and my shop is a separate building so the climate is milder and I don't have to keep things warm all the time in winter. My mini split is pretty "ordinary", but it does have a heating function that works well most of the time in winter. If it gets below about 20* F it's not so good. I think there are units available that have supplemental heating and some of the newer units will function better at lower temps.

 

[polizei1]

Awesome, thanks for the help guys!

 

[theoldwizard1]

Awesome, thanks. Can the lines be ran through the interior 2x4's, or would they have to be exposed on the interior wall?

As other have said, yes, it can be done, but it is not easy ! I would start by making the walls with 2x6s. You are going to need some BIG holes to run those insulated lines through. This is not copper wire (i.e. not a flexible) so 90° corners will likely have to be pieced together (brazed) and then insulated.

Yea I'm in Ohio, temps get into the negatives. Sounds like I may be better off sticking with the Reznor for heat and getting a separate cooling mini split.

If you are going to buy a mini-split A/C, upgrade it to a heat pump ! Heat pumps are most cost effective in the "shoulder" months (any time the outside temps are between about 0F and 65F). They do not heat as quickly as a gas fired unit.

Personally, I would just go with the mini-split and then some other portable heat for those few sub-zero nights.

 

[yeldogt]

If you have NG -- that is normally the cheaper way to heat .. even with a very efficient HP. You have to include the cost of the two systems.

I think you will find the need to keep the space heated -- it can take a long time to heat up a very cold space. Plus - all the tools and supplies will freeze. I maintain a minimum temp.

 

[polizei1]

It's been a few months, construction on my house started a few weeks ago so I'm re-visiting this topic.

For you guys that have the AC lines ran through the walls, do you have any pictures? At this point I'm convinced on a Reznor NG heater and a separate mini-split. I still have not decided on size or brand, any suggestions? Right now I'm looking at 12-18k Mitsubishi M-Series. BTW: I'm much more concerned with cooling the 3rd bay, rather than a "need" to consistently cool the entire garage.

It's hard to tell on the Sketchup, but the front of the house is stone (on the bottom) so I need to figure this out before they start laying the stone. I definitely want to go through near the bottom where the condenser and any lines will be hidden with bushes.

I would like to be able to access the lines, but as EdT mentioned, normal AC lines are buried in a house anyway...how much of a concern is this?

Thanks guys!

 

[PoorOwner]

if you plan to use a cavity between studs where the lineset just goes down and out, you can potentially rough in a lineset. Going through studs, the big hole you would have to drill, I wouldn't feel comfortable unless it is 2x6 stud. Remember the condensate pipe needs to be done as well, and it is better to use PVC pipe. It is no different than central AC stuff. What happens is that people actually install the unit first with a piece of drywall around the indoor unit, it gets textured and finished when the rest of the drywall goes up.

in auto mode, the fan goes to a low speed when it is cool enough, and it just sort of lightly circulate it's around 2 stalls unless you put the fan speed higher. If I wanted a little cooler in the 3rd stall I run ceiling fan.

Note that for the mitsubishi, the 18K is a much bigger machine as it uses the same shell as the 24K, than the smaller 12K condenser. It is 36"h x 33"w.

There is also a 15k unit you can consider

 

[polizei1]

Would the 12k be enough or do I "need" the 15 or 18k? I don't necessarily care about the size of the unit, as it will be sitting up high on the wall. I just want a functionally cool space, mainly in the 3rd bay.

I'll talk to my builder before framing starts, maybe I'll make that wall 2x6's like you said.

 

[Jackfre]

"Hide it with bushes" Not a good idea unless you can place the bushes more than 4' away and keep them trimmed to that distance. Restrict the air flow, restrict the output!

 

[PoorOwner]

Would the 12k be enough or do I "need" the 15 or 18k? I don't necessarily care about the size of the unit, as it will be sitting up high on the wall. I just want a functionally cool space, mainly in the 3rd bay.

I'll talk to my builder before framing starts, maybe I'll make that wall 2x6's like you said.

I have the 18k in mine and it is 660 sq ft mostly uninsulated. The backwall and ceiling is insulated as they are attached to the living quarters. If set to 73 and it is 80 degrees in it, it is high 90s to 104 outside.. it pulls down a few degrees in the hour or so and then just goes into a lower consumption mode to approach the set temp. I could even do 12k. The orientation of the garage has alot of do with it, mine is north facing with little sun. I had replaced with non insulated, single steel pane garage doors, and man door with insulated version with weather seals, otherwise it would have been a problem as they let in alot of heat and cold.

the only time it had struggled at 75 degrees for a while is when we had both cars operated that day, I used a infrared to check the car tires and they are relatively warm giving alot of heat load. It continues to blow onto the work area so 75 is cooler than it seems. It sounds like yours is going to be well insulated, I think the 12K will do fine blowing on you while working, eventually it should heat or cool the whole garage, one thing to consider though is maybe get a hyperheat 18K and skip the gas heater.

 

[polizei1]

Interesting, I'll check out the Hyperheat. It says it's good to -13*, which is probably about my limit where I'm at.

I'll have insulated walls all the way around, in the ceiling, and garage doors. Sounds like the 12k would be plenty and save me almost $1k over the 18k.

Edit, I looked at the h2i hyperheat 18k, it would cost more than the Reznor 60k and the M-series 12k mini-split, so I don't think that's a viable option. I also think it would cost more to run than the NG.

I'm looking at these:

https://www.ecomfort.com/Reznor-UDAP-60/p46972.html

https://www.ecomfort.com/Mitsubishi-MY-GL12NA/p65343.html

vs. the h2i

https://www.ecomfort.com/Mitsubishi-MZ-FH18NAH/p79447.html

 

[theoldwizard1]

if you plan to use a cavity between studs where the lineset just goes down and out, you can potentially rough in a lineset. Going through studs, the big hole you would have to drill, I wouldn't feel comfortable unless it is 2x6 stud.

This why mini-split vendors recommend going straight out the outside wall.

Insulation on the tubing is MANDATORY. Making a 90° interior corner (either inside or outside corner) is a challenge. I think you would have to cut the pipe and then re-braze and re-insulate it.

If you want to mount the air handler on an inside wall, I would suggest that the pipes enter the stud cavity and go straight down to the basement. This is still a challenge.

 

[PoorOwner]

I looked up some data for your location.
https://www.usclimatedata.com/climate/cincinnati/ohio/united-states/usoh0188
says the coldest is in Jan with avg low 22 and avg high 39.
is -13 freak record temps?

I don't know which one is cheaper for you to operate, if you use too much of gas or electricity, you will probably pay more due to tiered pricing. Assuming you already use gas furnace inside the house.

How big is the Reznor you are looking at? installation costs? The ones I see always have like 40,000 BTU or something and I feel that would be for a much larger space.
Doesn't seem your garage will be much harder to cool or heat than living quarters, you won't need gas AND electric in your living room, so the garage probably doesn't if you get the correct sized unit. One thing about gas heating, they just kick on and off and go over a couple degrees, is not as comfortable than a mini split inverter modulating to keep the set temperature.

 

[justinjoyal]

Would the 12k be enough or do I "need" the 15 or 18k? I don't necessarily care about the size of the unit, as it will be sitting up high on the wall. I just want a functionally cool space, mainly in the 3rd bay.

I'll talk to my builder before framing starts, maybe I'll make that wall 2x6's like you said.

Sizing depends on the cooling/heating load. Outside temps, sun and insulation are the major factors.

750 sq ft is a small space. What kind of insulation are you putting in?

Btw a good quality high efficiency heat pump will provide plenty of heat down to -22 F.

It's been a few months, construction on my house started a few weeks ago so I'm re-visiting this topic.

For you guys that have the AC lines ran through the walls, do you have any pictures? At this point I'm convinced on a Reznor NG heater and a separate mini-split. I still have not decided on size or brand, any suggestions? Right now I'm looking at 12-18k Mitsubishi M-Series. BTW: I'm much more concerned with cooling the 3rd bay, rather than a "need" to consistently cool the entire garage.

It's hard to tell on the Sketchup, but the front of the house is stone (on the bottom) so I need to figure this out before they start laying the stone. I definitely want to go through near the bottom where the condenser and any lines will be hidden with bushes.

I would like to be able to access the lines, but as EdT mentioned, normal AC lines are buried in a house anyway...how much of a concern is this?

Thanks guys!

The easiest, safest way is to install the system after everything else is done.

Drill a 2 1/2in hole through the wall, hang the wall unit and do the rest from the outside. Get color-matched aluminum to hide the lineset.

If you’re gonna run everything inside the wall you gotta make sure the lines are not damaged by nails, screws or whatever.

Making a 90° interior corner (either inside or outside corner) is a challenge. I think you would have to cut the pipe and then re-braze and re-insulate it..

Absolutely not.

3/8 and under is easily bent by hand. 1/2 to 3/4 a bender will do the trick 90% of the time.

The less you braze the better it is.

 

[highflier]

Line sets run in walls are not a big deal.
That is the standard way it's done in my region.
For sure 2x6 top plate is better to work with.
I prefer 2x6 for any walls that will have plumbling, interior or exterior.

As to future line set issues, not common at all.
But, if the need arises, you can run a new set on the exterior of the house.

I would not install the AC after construction is completed.
AC will be last in line for placement, not desirable.

My prefered schedule is: HVAC, plumbling, electrical.

 

[yeldogt]

I'm a bit confused .. now you are placing the unit on a wall ?

The tubing can be manipulated using a bender -- no issues placing inside a 2x4 wall. Better to bend properly and have a continuous pipe. The pipes both get insulated .. you also want to have a gravity drain if at all possible ... and placing it in a PVC pipe or using PVC pipe is the way to go. You don't want to have to clean out the flex pipe in the wall.

Heat pumps have always been popular in areas where the need for heat is not as great as AC -- Install one appliance -- done. For the few days a year when really cold -- electric resistance coils provided the heat. The key was always -- how many days are you paying for expensive electric heat. Modern HP's have changed the formula -- the best can provide all the heat that is needed down to almost any temp. Most of the negatives around HP's are due to them being cheap for builders to install -- Install a heat pump in an area that is really not suited and problem occurs -- the builder doesn't care .. he is off building another house and you are paying the bill. As i said -- modern HP's are changing this.

But - With current low NG prices -- most HP are still going to be more expensive to run as the temps drop. How much depends on location and use --

You need to get a proper heat/ cool load on the space based on construction and then guess how you want to heat ... understand the the units "rise" per hour. A unit able to maintain a given temp will not be able to give you a 30 degree rise in one hour. With a new garage and NG available -- the option to have both comes into play. Most people don't have all the options.

With NG available -- I would spend all that's required to make the space efficient ... install a properly sided NG heater. You will find maintaining a nice temp is not all that expensive, for a few hundred dollars a heating season -- you will enjoy the space.

 

[polizei1]

Reznor's website has a BTU calculator that states 45k is the smallest recommended unit. That means I can choose that, or the 60k which is the next step up for $25 more.

https://www.reznorparts.com/Heater.mvc.aspx/GarageCalculator

https://www.ecomfort.com/Reznor-UDAP-45/p46968.html

The debate about pricing is something I'm totally oblivious too; what I can say is that right now, neither unit (AC or heat) would be ran all the time, it would be on periodically throughout the season at best. That may change in time, depending on how often I'm working in the garage. I've just heard that NG is substantially cheaper to use than electric (at least in my area it seems). If it makes a difference, the furnace, dryer, appliances, fireplace, and grill are all NG. Having the option of both is what I thought would be the best solution, especially considering that it's a slightly cheaper to boot.

PoorOwner, Ohio gets into the negatives, especially with the windchill. Temps of 5-15 are pretty common, but the winter harshness can fluctuate quite a bit.

https://www.accuweather.com/en/us/cincinnati-oh/45229/month/350126?monyr=1/01/2016

You can see the temperature gets into the single digits, but it's never really consistent. This year was a really mild winter. Summer is the same, mostly 75-85 but can spike up to 100.

As for the lineset, my plan is to mount the condenser/heatpump/big metal thing on the outside, on a concrete pad. Then, run the lineset through the front and up the interior wall. I assume there would be enough room to use PVC pipe and therefor, have it drain to the outside, especially if I have them do a 2x6 instead of 2x4.

BTW: I won't be doing this, a certified HVAC guy will, so no worries there.

What am I missing here? I'm just trying to figure it out and do it right the first time!

 

[justinjoyal]

Seems like you got it figured out.

Even if you decide to go the NG route, get a heat pump. The price difference is minimal and you will have heating capability if needed.

 

[polizei1]

Any preference in the brand? I see LG, Mitsubishi, and Fujitsu. If I can find a heat pump around the same price, I do agree that would make the most sense, unless there are reasons not to that someone could point out?

 

[justinjoyal]

Compare specs, warranty and prices and go from there. Service is also important so make sure you find someone who can deal with the brand you chose if a problem arises.