Adding A/C to your garage

This year we have had several new and past clients call about adding a/c to there garage.  For most people they would think it would be a waste of money and energy, but for us who live in Arizona were the summer temperatures reach 115 it's not uncommon.  Normally the best solution to heat/cool a garage would be a ductless mini split, but in some cases adding a central a/c unit is more efficient to handle the heat load.  When choosing to install a ductless mini split make sure you choose a system with inverter technology.  The inverted systems optimize energy consumption with the change of ambient temperature making the compressor run at different speeds.  So if you have a 12,000 btu systems it could be cooling/heating at 9,000 but if the heat gain increases in the conditioned area then the system can heat/cool up to 12,000 btu.  Ductless mini splits come in single, dual, tri, and quad zones.  Most garages we install mini splits for are only 800 sq ft or less and only require single zone systems, but in some cause we're the garage is 800 or more then we would install a dual zone system.

     Different ways to install ductless mini splits in you garage.

Exposed refrigeration lines ran down the wall inside the garage.  We don't typically like to install the lines this way because of the look, but sometimes the homeowners association won't approve line set covers on the side of the house.

Copper refrigeration lines ran inside the way.  This way is very tricky to install because you have to bend the copper lines just right so that the air curtain snaps onto the back frame.  We always make sure to pressure test the lines and check for leaks before patching up drywall.  In most cases when it is installed in the Garage we will install a white covered access door just incase we need to get to the flared fittings.

If you don't have a homeowners association then you can install the refrigeration lines on the outside of the wall along with the condensation drain line.  We use 4'' abs pipe to go through the wall that way everything is sealed and the copper and drain lines go through the wall smoothly.











                                  Ways not to install ductless mini splits

Placement is a key factor to a for both efficiency and maintenance.  You need to be at least 4 inches from the ceiling (we prefer 6).  If a air curtain is to close to the wall it will not have enough air to breath and opening the face to get to the filters and electrical will be difficult.  Outdoor units must have 12'' ( Arizona code) around the complete unit and the outdoor fan can not be facing a structure wall.  We have seen several condensers installed incorrectly cause the system to overheat.

Lg have mini split air curtains that can be a mirrored finish or even the LG art which is a picture frame style.  If you don't want to spend the extra $$$ you can get creative and design your own art.

              Central heat pump split system installed in garage

We recently had a customer who wanted to add a/c and heat to there 4 car garage.  It was a split style garage which was around 1,000 sq ft.  For this size we could install a 12,000 btu tri mini split to satisfy the garage.  This would be three 12,000 btu air curtains and one 36,000 btu outdoor condenser.  The installation process would include cutting drywall and the attic space was extremely tight. After exploring all the options we decided the best system would be a central heat pump system.  The garage had high ceilings and no attic so we would have to use exposed spiral ducting.  We started off by building a platform in the corner of the garage so that he still had room for his off road jeeps and toys.  We built the platform and lined it with sheet metal to give it a nice look. We also insulated the platform inside with duct board to reduce the noise of the return.  We installed two return grills that were sized for the 3 ton unit.  The ducting for this install was difficult because of the high ceilings and finding studs to secure the duct straps.  We do a lot of garage installs but this one is by far my favorite.  Usually we will install the unit in the attic and run flex ducting or install the unit on the platform and add a plenum box with some registers.  This customer went all out with the ducting.  He choose the thick spiral ducting and curved registers that matched the spiral.  It gives the final install a clean finish compared to tap registers that are square.  Overall the install took two days to finish from installing the equipment and ducting to running new power to both units.  The customers was very happy and the system cools the garage great.  One thing that you have to remember when wanting to have a/c in you garage is to always have a split unit installed.  Never attached ducting from your existing system to cool the garage.  This method is not allowed in Arizona because the air you are cooling the garage with is not coming back to the system.  This cause you existing system to find the lost air needed and the system will pull from leaks and cracks within the house.  Not only that but the garage has unwanted co2 and dirty air that you don't want in your house.

Garage install with no ducting