Heat pump external unit - what clearance?

Changing the subject a little here - we are thinking of getting a heat pump. Is it true it should only be installed on an outside wall? Or can it be on any wall providing its close to tne outside unit.

Answer to post #7
First part of your question the answer is: NO it is not true.
Second part : can be on internal wall as long as you can get the pipework and the drainage to the outside. eg; Our unit (floor mount) is on an internal wall and is six to eight metres away from the outside unit. Any moisture is pumped from the inside unit to a drain on the outside.

Perfectimages - Great, thank you for clarifying that.

+1
all mine are on internal walls and pipe under the house. one actually pipes through into a wardrobe and then down through the floor.
this was because there was no where to mount it on the outside walls due to windows and that i don't want holes cut through the cladding.

Searches showed 300-600 mm. (1-2 feet). Thinking of putting a retaining wall in garden, 2 blocks high, in front of the unit. Greater clearance sounds a better choice.

Think about the airflow, if you put anything in front of unit, (including plants) the air will short cycle(reflect back from object) back to air intake, causing loss of performance and efficiency. IMO (my Trade) 600 is way too close for a wall, but if only 2 blocks high, perhaps ok, more would be better(assuming top is still below center of fan blade), but an angled deflector on unit side, to direct air up and over would be good.
Personally i have refused to do installs, in narrow pathways of a 1m+, unless it has good airflow along/thru it, as the worst preforming units in the depths of winter, are often those, and i can not be bothered with customer complaints about it.

As an over the top example of restricting airflow, a Funny one i went to, where unit had killed its compressor, customer had built a garden shed enclosing it, his thinking was the dry air would keep his tools from rusting.
Others have often been plants, causing recycled air, which is steam when defrosting, which killed main boards on 2 examples.

gpg58 - thanks for that.
Will re-configure wall so its line is perpendicular to the unit and moved further away from the edge of the unit. Have a pile of stones that can fill the space between, to keep weeds out.

Good choice.
Heres a pic of one i went too, that was claiming low performance was a warranty issue, declined.
https://trademe.tmcdn.co.nz/photoserver/full/1298917397.jpg

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