HVAC Install ideas...

[Daytrepper]

Hi fellas,

I am going to be installing an HVAC system in the garage in the next couple weeks, and am looking for some opinions on a few dilemmas I have.

Plan right now is to use a 3 ton gas pack unit (LP) outside of the garage. I have the return ducting figured out, but have a bit of a dilemma on how to get the main trunk duct from the unit up to the attic to the plenum box. I want to avoid running this huge duct inside the garage if at all possible.

One possible scenario is a 14" trunk line up from the unit, up the outside of the back wall of the garage (would have a box built around it) and into the attic to the plenum box. It would be encased in a "box" and insulated of course.

Other scenario is bring it inside the garage, then up the wall, into the attic. Ideally, I do NOT want to run it inside the garage. It would take up quite a bit of space, I would have to move several things around, plus, it would be unsightly.

Does anyone see any potential issues running it up the wall, outside? Is this a feasible way to do it? Has anyone done it this way? Any other suggestions/advice you could offer?

I am stuck, as there is not enough room in the walls, and going with a split system (in the attic) will be a much harder and more expensive option.

Garage is 30x30x10, drywalled and insulated. Thanks for the suggestions.

 

[Charles (in GA)]

Does anyone see any potential issues running it up the wall, outside? Is this a feasible way to do it? Has anyone done it this way? Any other suggestions/advice you could offer?

I see this done all the time around here on commercial buildings, older ones usually where its not feasible to install split unit with air handler inside. Unit butted up to the building outside, return duct thru the wall to it, and a duct outside running up the wall and then it runs thru the wall to the inside.

Charles

 

[RobertMo1988]

with a split system you can keep your furnace/air handler in a closet if you have one or you could build one around it in the garage. you could run your lineset on the exterior of the garage/house with a cover over it...

Or duct up the side of the garage as high as you can go. Duct into the garage and shoot your plenums in thru the attic.

OR put it on the roof, on a adjustable curb. but then you are cutting your roof open.

 

[Daytrepper]

with a split system you can keep your furnace/air handler in a closet if you have one or you could build one around it in the garage. you could run your lineset on the exterior of the garage/house with a cover over it...

Or duct up the side of the garage as high as you can go. Duct into the garage and shoot your plenums in thru the attic.

OR put it on the roof, on a adjustable curb. but then you are cutting your roof open.

Thanks for the replies fellas.

The more I think about it the more a split gas system looks like the way to go, more difficult or not. I'd rather just run the lines in a case up the side of the wall to the attic rather than a huge trunk duct.

 

[mpire]

I don't see why you can't just hang it from the ceiling in the garage. If its up out of the way, it shouldn't be a huge problem, right?

 

[Daytrepper]

I don't see why you can't just hang it from the ceiling in the garage. If its up out of the way, it shouldn't be a huge problem, right?

The more I think about this, the more I am considering just going with a regular hanging heating unit (like the Mr.Heater big maxx), and a wall mount air conditioner. The time, expense and amount of work to install a complete HVAC system is starting to not look like such a hot idea. With the money I save I could go buy more useful things, and more toys....

 

[RobertMo1988]

hang a package unit from the ceiling?i bet its probably atleast 3'x3'x3' and weighs probably 300-400lbs

 

[Daytrepper]

If I end up doing an HVAC full system, it will be a split system, and the furnace/air handler will go in the attic.

 

[mpire]

hang a package unit from the ceiling?i bet its probably atleast 3'x3'x3' and weighs probably 300-400lbs

They are smaller in Florida.

Apparently I don't have a clue.

 

[Daytrepper]

After much consideration, here is what is going to go in...

This will be the furnace of choice for the garage, the 75k btu model:

http://www.dornbackfurnace.com/pdfs/unitheaters.pdf

Looking at the specs, at 25-35 degrees, garage should be to 72 in about 20 minutes.

A/C will be very similar to this, except a wall mount unit:

http://www.homedepot.com/Appliances...splay?langId=-1&storeId=10051&catalogId=10053

This system is about 1/2 the cost, 7/8 the work, and will do just as good, if not better!

Thought about it, and if I lived out here in the shop (almost do, but not quite lol) I'd do the full HVAC system. I think this alternative will be a fine setup.

 

[7echo]

Seems like a good application for a mini-split, but your plan seems fine. And less money than a mini-split system.

 

[Daytrepper]

Got the furnace in today....but it was damaged....looked like UPS rolled it down a hill....looking forward to the replacement.

Ive got a couple dilemmas on the a/c unit. A buddy that works with HVAC suggested installing the A/C unit in the north facing wall of the garage (for efficiency), but that is a side wall, and would mean tearing out lots of drywall to build a true opening with a header installed, etc. Another buddy in the construction trade suggested install it in the gable wall, no header needed...just frame an opening. He says the gable walls are not the major supporting walls, it is the sidewalls, so that is why no header would be needed.

North wall is an easy option electric wise, as is the western gable wall...but the header and all that would be necessary for a 30" opening? Would it really be that much less efficient in the western wall, which gets the hot NC sun for 1/2 the day?

I would prefer it in the western wall, or the southern wall....mostly for looks though. Tons of trees around here, so not an all day sun issue on the a/c unit, but the northern wall is the least exposed.