How High Should A Heat Pump Be Off The Ground?


If you know the anticipated snow fall level for your area, that is a good height for your heat pump. It never hurts to add a few inches for safe measures. Having one year of unusually high snow fall would be an okay gauge to plan for, just know that the higher the better for proper drainage.

For those lucky dogs that live in more temperate climates were not much snow is ever expected then I like to see these units up about 6 inches or so. Read on to see why. I also have some useful products listed below.

Did you know that a heat pump systems outdoor unit leaks water in the winter? And, where that water comes from? I wrote an entire article on just that, but read on and get the quick answer.

Reasons Why Heat Pumps Should Be Elevated

In the summer months when it’s roasting outside and your air conditioner is really rockin, the inside unit is blowing air through the indoor coil and cool air is coming out of your registers using the process of refrigeration.

It’s also picking up moisture out of the air passing through the coil and this moisture is either drained away most commonly through that white PVC pipe sticking out of your furnace.

The outdoor unit is picking up that heat that was in your house and removing that heat to the great of outdoors. That’s why when you put you hand over the outdoor fan the air is substantially hotter than the outdoor air or ambient air.

That’s the simple answer of what a heat pump does. It finds the heat and moves it from one place to another.

In the winter when your begging for a warm house everything is reversed. Your heat pump is now finding the heat that exists in the air outside and magnifying that heat with the air of a compressor and moving it into your home.

The indoor coil is now the hot coil and the outdoor coil is the cold one. Out there laboring away trying to pick up on some heat. It can do this because heat actually exists in everything down to absolute zero. Trust me, that’s COLD.

And, while that noisy old heat pump is doing all it can to pick up on that heat in the air it’s also picking up moisture just like the indoor coil was doing in the summertime indoors.

But now it’s picking up moisture in a cold environment, outside, not in the warm indoors. So now that moisture is going to freeze onto the outdoor coil.

This is why a heat pump has a defrost cycle. Periodically, depending on the area you live, either lots of snow and ice or not much, your heat pump will make funny noises and blow steam out the top.

The fan will stop and the compressor will keep running and for a short time the unit reverses itself into the summer mode of cooling. The outdoor coil becomes the hot coil and melts the ice.

But now, instead of that condensation draining down a PVC pipe it has to drain out the bottom of the unit. Remember the condensation had to drain away at the indoor unit in the summer.

In winter it has to drain away or it will become a gigantic cluster of ice in the bottom of your heat pump.

Looking down into an old dead heat pump with the top off

Heat pump manufacturers evidently knew this so the put drain holes in the bottom of there units. But when you have a heat pump placed directly on the pad most of those best intentioned drain holes are blocked.

To top that off, these drain holes are mostly very small and it only takes a little bit of debris from leaves or anything else that can find it’s way into that big hole on the top to totally plug the drain holes.

And to top that off, when the leaves and junk at the bottom begin to decay and grow into a slimy mess your good old buddy “rust” comes to visit.

I can even top that one off. When the ice that melts can’t drain away and it becomes an iceberg it can attack the coil and copper tubing with a vengeance.

crushed refrigeration pipe

When ice forms around the bottom of your heat pump coil and is allowed to continue freezing without melting and draining away then this can result.

This is an extreme case and was a seriously neglected unit.

The power of ice is amazing and I’m sure certain conditions had to be met to result in this crushing effect.

What Should I Use To Raise My Heat Pump?

When I say “jump” you say “how high” right? In my area a usual snow fall is three to six inches. The heat pumps I install have 6″ pump ups or raisers underneath them on an oversized artificial concrete pad.

Even when a concrete patio or pavers are already there I like to add a pad just to keep the unit up. I also like the oversized pads to keep other landscaping and debris away from the unit. More space for drainage.

Amazon has both pads and risers. If you unit already has a pad but is in somewhat shabby condition, it’s possible to replace these items if extreme care is taken not to create any leaks in the refrigeration lines while making the change.

If you can’t feasibly do this yourself hire a good technician. The things I’ve talked about are certainly easier done on a new installation. A good HVAC company should be aware of how important it is to keep a heat pump in the air.

If your snow fall and ice problems are greater than what a 6″ riser will handle then consider a stand. I had to build one for my own heat pump.

This heat pump is up there about 18″ because the snow is intense on this side of the house. We sold this place and the new owner put a roof over the heat pump to keep the snow and ice from the roof away from the unit.

I found one stand on Amazon that looked substantial and adjustable.

Conclusion

I hope this helps. Everything mentioned here has been what I call necessary items for the long life of a heat pump. Heat pumps have a notoriously poor reputation for problems and short life span compared to there expense.

I would say that about 90% of those problems are installation related.

A heat pump installed the right way can save a lot of money in the long run if everything is done right the day they are installed.

The best day in the life of a heat pump is the day it was installed.

Chad Peterson

Chad Peterson is near 40 year veteran of the HVAC industry. "I like to explain heating and air conditioning problems in a way the average home owner can understand. "

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