20kW
House has duel fuel heating and ac combination that cover the house in two zones..During the heating season, the two heat pumps take care of both zones down to 40º. Below 40º, the gas furnaces take over........ System is great, but with one major flaw...... Most snow and ice come in the low 30's and below....... Thus both heat pump units now load up through their grilled tops with ice and snow........Out comes the sun, temp 40º and the heat pumps kick in.....or try......The center mounted fan, now caked in a layer of ice and snow will not rotate.........If not tended to, can easily burn out!
This last nor'easter, here in Virginia, left a good inch layer of ice on everything, topped with 6 inches of snow.....took a lot of chopping to get the ice off the blades of both heat pump fans.......

Retired, and having nothing better to do....... I came up with the following..

Circular fan opening is 25 inches across.......

Bought two metal snow pans (kids type of snow sled) on line( 26" inch in diameter)

Welded four 3/4 inch (ID) x 3 inch long metal conduit, evenly spaced around the edge of the open side of the pans.

One inch from end of each piece of conduit, I had pre-welded 1/4 20 nut over a pre-drilled hole for 1/4 20 bolt to act as a set screw.

1/2" pipe was cut to 5 inches for the legs needed to make them stand on the fan grill.......chair leg bumpers added on to the ends of the legs.

For now, for the extra insurance, they are held down over the fan grills with with a bungee cord...........

Tested... plenty of air flows freely and they should block most of the freezing rain and most snow.......

If it works well in this next storm, just have to find a good matching paint.........

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d11gnccer
All manufacturers are different but Carrier product data specifies 5 feet clearance above fan on heat pumps as air will recirculate through the coil and drop efficiencies or possibly cause excessive ice build up between defrost cycles. It prob won't be much of an issue but I would definitely remove them before summer.
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20kW
d11gnccer;37778 wrote:
I would definitely remove them before summer.


Will be gone the day after any winter storm......quick on quick off!
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UPS
Here's a commercial version of this:
[URL="http://www.innoprohvac.com/en-CA/documentation"]http://www.innoprohvac.com/en-CA/documentation[/URL]

How about adding a second pan on each unit? An upward-facing pan under the existing downward-facing pan - creating a flying saucer shape. The top pan would continue to block / shed snow, while the bottom pan would direct the air flow out and away, rather than downward into the intake area.
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Canada_Guy
I've never really thought about it before as we don't typically get a lot of snow, but now I can appreciate the design of my Trane unit. It has a solid top with the exhaust fins around the sides.

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20kW
I got the above basic idea from seeing this on line...tried contacting the company but got no response (web sight is dated 2014).........seemed to be the right answer to this particular problem.....

Tried to isolate image from ad with NG results.......

[URL="http://www.acshield.net"]www.acshield.net[/URL]
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UPS
20kW;37791 wrote:
I got the above basic idea from seeing this on line...tried contacting the company but got no response (web sight is dated 2014).........seemed to be the right answer to this particular problem.....

Tried to isolate image from ad with NG results.......

[URL="http://www.acshield.net"]www.acshield.net[/URL]


Even with vents in the top, that one mounts very close to the top of the system. Any of these would work best if they did not direct air downward to be drawn back into the system.

Found they have a YouTube video - funny actually:

[URL="https://www.youtube.com/watch?v=56zY6M1UAVU"]https://www.youtube.com/watch?v=56zY6M1UAVU[/URL]
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20kW
Air blows out pretty hard from all sides......I have a wind speed meter and will see what it reads without the lids and what comes out from the sides with the lids on..........

But again, below 40º, the fan is idle when the system switches to aux heat (Gas furnace could run for several days) .. and that's when the ice and snow builds up on the fan, blocking off the top of the unit with the potential of fan and fan motor damage when the outside temp returns to 40º...

If you watch the posted Youtube as posted by [B]UPS[/B]......

[URL="https://www.youtube.com/watch?v=56zY6M1UAVU"]https://www.youtube.com/watch?v=56zY6M1UAVU[/URL]

There is another lid system that can only be sold through a dealer .. Kool Kap ($$$$)... works like a toilet flapper valve.......
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20kW
Just so happen to have a wind speed indicator (skymate) from my sail boating days.

Cover off at 10" inches above fan, best reading average 5.5 knots at outer edge of fan.. (lower towards center)..

Cover on, 10 inches from the outer edge of the cover, all sides... 5.4-5.5 knots...
I see no reverse air flow problem..........


Thinking about the saucer shape (above coment):
Water follows a curve...I don't want anything entering that can freeze on the stationary fan blades (heat pump is off below 40º)..
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