Quick answer: In snowy areas, lift your mini split's outdoor unit above the snow. A wall bracket or a ground stand does this best. A flat pad is fine where snow stays low. MRCOOL says to prevent ice buildup, keep air moving around the unit, and run the drain hose as straight down as you can.
Picking a spot for the outdoor unit? Our mini split placement guide covers where it should go. This post covers what it should sit on. We compare wall brackets, pads, and stands for winter, using MRCOOL's own install manuals.
Why does the outdoor unit need to sit above the snow?
A mini split heats your home by pulling heat from the outdoor air. In cold weather, frost forms on the outdoor coil. The unit runs a defrost cycle to melt it. MRCOOL's support page says snow or rain covering the unit can make frost build up faster. It also says to keep the unit clear of snow.
Defrost also makes water. That water drips out of the base of the unit. When the unit sits low, the water can freeze around it and build up ice. MRCOOL's 5th Gen DIY manual says that where snowfall is expected, you should "take appropriate measures to prevent ice buildup and coil damage."
MRCOOL's VersaPro and Hyper Heat central ducted manual is even more specific. It says the outdoor unit must sit on a riser at least 6 inches tall, or higher per local code, to get above local mean snowfall. That is a good rule of thumb for any heat pump in snow country.
What does MRCOOL's manual say about mounting the outdoor unit?
The 5th Gen DIY quick start guide says to place the outdoor unit "on a pad or bracket with proper clearances." The full manual adds these rules:
- Bolt it down. Anchor the unit to the ground or to a wall bracket with M10 bolts.
- Use a strong wall. A wall bracket needs solid brick, concrete, or a wall of similar strength. The wall must hold at least 4 times the unit's weight.
- Keep it level. Check that the bracket arms are level before you set the unit on them.
- Cut the noise. Rubber gaskets between the unit and bracket can reduce vibration and noise, where allowed.
- Leave space. The 5th Gen diagram shows at least 4 inches behind the unit and 20 inches in front of the fan.
- Use a shelter, not a wrap. For heavy snow, build a shelter above the unit. MRCOOL says to be careful not to block airflow around it.
The manual also lists the size of each outdoor unit. The 9K and 12K (115V) units are 30.1 inches wide. The 18K unit is 35.0 inches wide. The 24K and 36K units are 37.2 inches wide. Check these sizes against any pad, stand, or bracket before you buy.
Wall bracket vs pad vs stand: how do they compare?
Here is a side by side look at the three common ways to mount the outdoor unit.
| Mount type | Height | Best for | Watch out for | Example at Chill |
|---|---|---|---|---|
| Equipment pad | Pad is 3 inches tall | Level ground where snow stays low | Snow and ice can pile up past 3 inches | Outdoor Pad for Mini Split Condenser, 38 x 18 x 3 inches, fits 9K to 36K |
| Ground stand | Stand is 18.9 inches tall | Snowy yards and spots without a strong wall | Needs firm, level ground under its feet | CoolGuard ACB-J02 stand, holds up to 220 lbs |
| Wall bracket | You pick the height on the wall | Deep snow, small yards, and keeping the unit off the ground | Wall must hold 4 times the unit's weight | MRCOOL brackets for 9K to 18K and 24K to 36K |
Sources: MRCOOL 5th Gen DIY manual and Chill product pages.
When is a wall bracket the best choice?
A wall bracket lifts the unit as high as you need. That makes it a strong pick in places that get deep snow or snow drifts. MRCOOL's bracket listing also says it keeps the unit out of the way and clean from dirt.
The trade off is the wall. MRCOOL's manual says the wall must be solid brick, concrete, or something just as strong. It must hold at least 4 times the unit's weight. Plan to leave at least 4 inches between the back of the unit and the wall.
Chill carries MRCOOL brackets in two sizes:
- The MRCOOL bracket for 9K, 12K and 18K units is steel with a white paint finish.
- The MRCOOL bracket for 24K, 27K and 36K units (model MB440A) also fits some central split condensers, per its listing.
When is a ground stand or a pad the better choice?
A ground stand works well when your wall is not strong enough for a bracket, or when you would rather not drill into it. The CoolGuard ACB-J02 stand is 18.9 inches tall and made of galvanized steel. It holds up to 220 pounds. Chill also carries the Pioneer floor stand in a 9K to 24K size and a 30K to 60K size.
A pad is the simplest choice. The Chill outdoor pad is 38 by 18 by 3 inches and made of recycled plastic that resists UV. It fits 9K to 36K units. It is a good base in mild winters. In snow country, 3 inches is less than the 6 inch riser MRCOOL calls for on its central ducted units. A stand or a wall bracket gives you more height.
Should I put a cover over my mini split in winter?
A roof style shelter above the unit is fine. MRCOOL's manual suggests one where heavy snow is common. MRCOOL's support page also says a cover or shield can protect the unit from wind and snow.
The key rule is airflow. The manual warns you not to block air flow around the unit. A full cover that wraps the sides and fan grille blocks that air. A mini split uses its outdoor unit to make heat in winter, so the outdoor unit needs open air all season long.
How do I keep defrost water from freezing?
The outdoor unit drains water in heat mode. Here is what MRCOOL's manuals say to do:
- Install the drain joint in the base pan hole before you bolt the unit down. Some units have a base pan with several drain holes and do not need it.
- Add a drain hose extension (not included) to carry the water away.
- Run the hose as straight down as you can. MRCOOL says slow drainage can freeze in the hose and flood the unit.
- Keep water off walkways. The central ducted manual warns that drain water can cause icy conditions on walkways.
Raising the unit with a bracket or stand gives the water room to fall clear of the unit. Want to know what defrost looks and sounds like inside? See our post on why a mini split blows cold air in heat mode.
What else should I plan for a winter install?
A pad or bracket is usually an optional add on. Our guide to what comes with a MRCOOL DIY mini split shows what else to add to your cart. Installing this season? Read our fall and winter install guide first.
Also pick a system built for your winters. The standard MRCOOL 5th Gen DIY heats in outdoor temperatures down to -13°F, per its manual. The Hyper Heat models heat down to -22°F. Our cold climate comparison breaks down the differences.
Still shopping?
Find brackets, pads, stands, and line set covers in our mini split accessories and MRCOOL DIY accessories collections. Still choosing a system? Browse the MRCOOL DIY 5th Gen lineup, or size your room with our free Manual J calculator. Want help picking the right mount for your system? Call Chill Mini Splits at (888) 231-8920.
FAQ
Is a wall bracket or a pad better for a mini split in snow?
A wall bracket is usually better in snow because you can mount the unit well above the snow line. A pad lifts the unit about 3 inches. MRCOOL's central ducted manual calls for a riser of at least 6 inches, or more per local code.
How high should a mini split outdoor unit be off the ground?
MRCOOL's central ducted heat pump manual says at least 6 inches, or higher per local code, to get above local mean snowfall. The DIY manual says to take steps to prevent ice buildup where snow is expected. Go higher in areas with deep snow.
Can I mount a mini split outdoor unit on a wood wall?
MRCOOL's 5th Gen DIY manual says the wall should be solid brick, concrete, or a similarly strong material. It must hold at least 4 times the unit's weight. Check your wall against that rule before you choose a bracket.
Does a MRCOOL DIY mini split come with a wall bracket?
Usually not. A pad or bracket is an optional add on for most systems, so check your listing. Chill carries MRCOOL wall brackets for 9K to 18K units and for 24K to 36K units, plus pads and ground stands.
Should I cover my mini split outdoor unit in winter?
Not with a full wrap while it runs. MRCOOL says not to block airflow around the unit. A roof style shelter or shield above the unit is fine and can help keep snow off.
Why is water or ice building up under my outdoor unit?
The unit drains water during defrost in heat mode. MRCOOL says to run the drain hose as straight down as possible so it does not freeze. For help with an ice problem on a MRCOOL unit, call MRCOOL support at 270-366-0457.
How much space does a mini split need behind a wall bracket?
The MRCOOL 5th Gen diagram shows at least 4 inches between the back of the unit and the wall. It also shows at least 20 inches in front of the fan. Check your model's manual for side and top clearances.
