2 ton mini split goes in this week- suggestions?

[TXNinAZ]

Hi all, I've got a tech coming in tomorrow/Tuesday to install a 2 ton mini split cooling only system in my garage, and I'm hoping for some input on what to watch for and to make sure he does it right.

It may cost me a few more dollars, but I'm going to ask that he run the line inside the wall, rather than a channel on the side of the house (HOA is a real PITA and I don't want to redo this because of something that stupid).

Should I have a separate terminal box on the exterior wall, no matter what? The unit will only be about 15 feet from the exterior-mounted 200 amp panel, but I'm guessing he should put up a terminal box anyway.

Can I put some kind of meter at the new condenser to monitor how much power it draws? I'd like to have an idea what impact it will have vs prior years' energy usage, but because I added a bunch of insulation last winter, it won't be as simple as just comparing previous bills. Thoughts?

I plan on keeping the unit running to maintain about 88* maximum and then lower it to 80* when I want to work out there. With no climate control, it generally reaches the low hundreds in July/August during the day, and not much below that at night.

I've researched before, but not fully happy with what I've found. The vinyl sweeps on the edges of the doors (one door is 16x8, the other 8x8) are pretty dry and stiff at this point, and leave me with a light gap around the doors that needs to be fixed so I don't try to cool Arizona. Any superior products I haven't seen yet?

Thanks, everyone- this is definitely the most helpful forum online!

 

[Falcon67]

AFAIK, code requires a disconnect at the unit. It won't cost much in parts and helps greatly for service. As far as energy metering, I'm not sure. I don't think there are any 240V Kill-a-watts. I'd use a clamp on amp meter to measure the current draw on the hot legs with the unit running, then note cycle times and calculate it out from there.

 

[Jackfre]

You would have to get a data-logger for elec consumption. Disconnect must be within reach of the unit.

 

[rlitman]

It may cost me a few more dollars, but I'm going to ask that he run the line inside the wall, rather than a channel on the side of the house

I'd expect it to cost you less. You wouldn't be paying for the "channel".

My unit had a way for the line to exit on the left, on the right, on the bottom, or to the rear (the method I'm using). On the wall, you could have it exit the side or bottom, run down the inside of the wall, and exit the wall near the bottom. It would be up to you to protect the plumbing running inside the wall.

 

[JakeKohl]

I'd expect it to cost you less. You wouldn't be paying for the "channel".

My unit had a way for the line to exit on the left, on the right, on the bottom, or to the rear (the method I'm using). On the wall, you could have it exit the side or bottom, run down the inside of the wall, and exit the wall near the bottom. It would be up to you to protect the plumbing running inside the wall.

I dunno about that - it's not easy running it inside a stud wall especially if going to a second floor. Access is tight, and the holes you have to create in the top and/or bottom plates are pretty big and laborious (on a ladder no-less). The angle the lineset needs to bend out of the interior unit to get into the wall cavity is uncomfortably tight too. The exterior channel mount stuff, although relatively price ($150 to $200 in materials) is REALLY easy to mount and run the lines in. You also have a drain line to consider and if it's in the wall, it will need to be insulated (or in the insulation) to prevent condensation.

Other things to look for: make sure they pressure check the system with nitrogen before charging it (pressure depends on system but can be 150 to 300psi). Once pressurized, they should soap the joints to look for leaks. Also check that they fine tune the refrigerant charge by measuring the super-cooling (assuming TXV unit).

Leak checking the drain line is useful as well and make sure the drain line is insulated anywhere it is exposed to warm air inside the house (it will probably produce condensate)

 

[rlitman]

I dunno about that - it's not easy running it inside a stud wall especially if going to a second floor. Access is tight, and the holes you have to create in the top and/or bottom plates are pretty big and laborious (on a ladder no-less). The angle the lineset needs to bend out of the interior unit to get into the wall cavity is uncomfortably tight too. The exterior channel mount stuff, although relatively price ($150 to $200 in materials) is REALLY easy to mount and run the lines in. You also have a drain line to consider and if it's in the wall, it will need to be insulated (or in the insulation) to prevent condensation.

Oh, you're talking about running it within the stud wall. Ouch! Yeah, that will be a heck of a lot more work.
I was assuming that it would be run on the garage side of the wall. Then you can box it in if you so choose.

 

[RKA]

I use an efergy E2 to monitor energy comsumption.
http://www.efergy.us/

It can log the data for download onto your PC if you want. I don't bother, I just watch it periodically to see what conditions cause what kind of power draw over time and do the math in my head so I have a sense for what it costs. That's how I discovered my unit is drawing a steady 270 watts while it's off. The efergy includes two clamps if you order direct from them. You'll need both for a 220 feed (connect one clamp to each 110 leg).

 

[whatuusay1]

I ran mine in the wall too - it looks much cleaner as well. I didn't have any problems with drain or condensation lines. I insulated my walls so I'm sure that helps.

 

[JakeKohl]

I ran mine in the wall too - it looks much cleaner as well. I didn't have any problems with drain or condensation lines. I insulated my walls so I'm sure that helps.

me too!

DSC_3027 by Team Seacats, on Flickr


DSC_3014 by Team Seacats, on Flickr


DSC_3020 by Team Seacats, on Flickr


DSC_3445 by Team Seacats, on Flickr

 

[pseudorealityx]

I can't really tell from the photos, but how far off the wall is the condensing unit sitting? You may want to grab the Installation and Operation Manual and make sure they're meeting the clearance requirement.

I'm saying this because it looks like it could be choking off the back side.

 

[JakeKohl]

I can't really tell from the photos, but how far off the wall is the condensing unit sitting? You may want to grab the Installation and Operation Manual and make sure they're meeting the clearance requirement.

I'm saying this because it looks like it could be choking off the back side.

They are a little closer to the wall than the manual indicated (they sit about 18" away from the back wall but they do look much closer than that in those pictures)...these are the heavy duty wall brackets that are often used and I've ever only seen two different models of the wall brackets - this heavy duty version and a smaller light duty version. The clearance specification in the manual is also in reference to an installation sitting on a pad on the ground. I figured the loss of a few inches of rear clearance would probably be offset by the additional air-flow available from under the units...besides, I'm pretty much committed to the installation at this point. ;-)

 

[LoneStarr]

Just started looking at LG Mini Splits for an attached garage around 525 sq ft.
with 8' ceiling. Not sure if 12,000 or 18,000 BTU's is appropriate considering air leaking around the garage doors.

LoneStarr

 

[JakeKohl]

Just started looking at LG Mini Splits for an attached garage around 525 sq ft.
with 8' ceiling. Not sure if 12,000 or 18,000 BTU's is appropriate considering air leaking around the garage doors.

LoneStarr

My garage is 864 sq ft with 10 foot ceilings (2nd story above) and a 12k BTU unit would have been adequate for cooling when I calculated it (by about 10%). I upsized to the 18k unit and have just fired them up. With it 95 degrees outside and just exposed stud walls with no insulation (other than the Overhead garage doors) it seems to easily keep the garage at 75 degrees. However, I don't have an attic directly above this space adding heat load. If you are insulated well and have insulated garage doors, the 12k unit would probably be fine.

HOWEVER, the 12k unit was not going to be able to keep up in the winter heating the space if it were 30 degrees outside due to the heat loss through the uninsulated slab.

 

[LoneStarr]

JakeKohl - I hadn't considered the attic space over the garage which has minimal insulation or the slab. Thanks for info. LS