Advice for keeping snow off a minisplit?
As I am getting for another bad New England winter, I clearly remember my last one, when we just got minisplits installed. It was daily duty to shovel them out. One installed on the North side would get bunch of wind-swept snow off the roof above and so would the one on the East side.
Unfortunately, I did not know it was possible to mount them on the wall, so they are sitting on concrete pad HVAC people installed it on. Maybe I wold put lattice on the side where prevailing winds are from and try to keep snow off it that.
I am thinking about building shed roof above both of them. Any thoughts? Advice? Experience?
Shed roof would be removed during warm season.
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Replies
Apollo,
Bite the bullet and spend the money to have the minisplit units mounted higher, either using wall-mount brackets or some type of elevated stand.
A shed roof above the unit is certainly a good idea, as long as there is enough clearance to ensure that air flow is not restricted.
A lattice, fence, or shed isn't such a good idea, because these features can restrict air flow and reduce the unit's efficiency. Tread lightly in that department.
There are lots of articles and Q&A threads on this issue at GBA. Here are a few:
Minisplit Heat Pumps and Blizzards
Tall minisplit stand for snowy climate?
Rules of Thumb for Ductless Minisplits
Please refer me to a commercial product or plans for a roof covering for snow and leaf protection for my two Mitsubishi minisplits
Apollo,
There are lots of photos online. I can provide a rating of various solutions.
This unit is too near the ground. The lattice may be the worst of all worlds -- not enough of a barrier to stop wind-blown snow, but enough of a barrier to interfere with air flow.
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The roof was a good idea, but again -- the unit is too close to grade.
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This one is elevated -- that's a good idea -- but the enclosure is a terrible design, because it is much too restrictive of air flow.
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Nice roof, excellent air flow -- but much too close to grade.
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Roof is a little stingy, and the unit is too close to grade.
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A temporary solution.
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Download the manufacturer's installation manual and study the clearance distances to objects, walls, etc. and add 50%. The shed roof approach works and is essential if the compressor unit is mounted in the path of eave cornice/ice-dam falls.
The shed roof in Martin's response #6 looks about right, even though mounting it at dead-grade level on an air-conditioning condenser pad is asking for trouble in snow country, even with a pretty good roof. Notice how much digging was required to keep it clear in response #2.
The compressors mounted 45-48" above grade on a deep energy retrofit I was involved with in Worcester, MA a few years ago fared just fine during last winter's ~120" of snow fall (most of which fell in a 5 week period), with no digging required (for the mini-splits, anyway.)
Dana,
just purchased Senville's 48,000 BTU condenser. They do not suggest placing it on a ground or wall mounted bracket, in due to its 52" height and 250lbs weight.
I would like to have my contractor pour a 6" concrete slab.
And either lay two
6 x 6 composite lumber posts
or
6 x 6 pressure treated post above the concrete for the inverter to sit on top of.
The condenser has a base pan heater and a small electric resistance element installed at the bottom of the cabinet.
a) would you recommend the composite lumber posts or rather the pressure treated post?
Considering moisture from drainage and the weight of the machine, longevity of posts
b) is gravel surrounding the cement pad sufficient or should the gravel also be placed under the cement itself?
(the ground is level, no slope)
I'm a novice and appreciate any advice.
I was thinking about #6 actually. These are Mitsu MXZ-2B20NA units.
Goal is to mount them on the wall next year, but I need a solution for this year. I hired an architect to make some changes to the house and mini-splits condensers may end up relocated anyway.
Do need to put something over them, because snow and icicles fall on them from roof above.
BTW, clearances required in this unit seem very low