Heat pump install, plumbing with three 90 degree bends

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kingdragonfly

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#261714 11-Dec-2019 15:11

I'd like to get a small residential heat pump professionally installed in an awkward place. It's for a single room about 3 x 4 meters.

If the outside condenser sits on the ground, it'll involve bending the plumbing three times with a 90 degree bends.

I'd guess it's about 3 meter length of piping.

I could also have the condenser sitting on a hanging shelf with straight short pipes.

Is this possible / advisable?

Cheers

timmmay

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#2372509 11-Dec-2019 15:31

The pipes for one of my heat pumps goes up into the eaves, over the wood beams in the roof, down through the wall, then into a heat pump, so lots of bends. It works fine, so I think yours will be fine too.

BlueShift

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#2372515 11-Dec-2019 15:34

Get a couple of quotes in, you'll be surprised at the places they can install them. Ours is on the second floor with the outside unit downstairs.

Kickinbac

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#2374476 12-Dec-2019 23:08

Three 90 degree bends won’t be an issue for a good fridgy. Probably stay away from the electricians installing heat pumps.

Scott3

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#2374490 13-Dec-2019 00:29

Installer should sort this all out for you.

With your bends, can a downwards gradient be maintained for the pipe run? If not you need a condensate pump, as the condensate in Air Con mode won't be able to free drain.

I picked a random high wall heat pump to see some specs:

https://www.panasonicaircon.co.nz/range/highwall/developer-series/cscu-rz35vkr

Min pipe run: 3m
Max pipe run: 20m
Additional gas needed if run is more than 7.5m

Bends need to have some radius (not be a hard miter bend, but this is unlikely to be an issue, refrigerant pipes are both under 10mm in diameter). Excessive bends does cause some pressure drop, but three 90deg bends would not be considered excessive, plus you are way under the max run length.

Especially in new build homes, it is not unusual for installs to not be "back to back", and have reasonable lengths of pipe run. Some heat pumps have stated max height changes, but this is normally 2+ stories.

Either wall mount or on the ground is fine. Generally ground mount is preferred, due to ease of install, and elimination of the risk of transmitting vibration into the structure.That minimum pipe run does need to be respected, although some floor console units don't have a minimum pipe run.

bfginger

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#2374814 13-Dec-2019 15:02

External condensate pumps are notorious for noise and poor reliability. If you've got a difficult installation situation you could get a cassette (ceiling) unit, which although being more expensive they should come with a condensate pump built in. Acoustic and efficiency technology in some cassette units is dated though.

It is possible to have the outdoors unit mounted on the roof if you must attach it to the building.

The linked to Panasonic model above is the "Developer" series. Some heat pump brands have no frills price point units aimed at cheep builders. There doesn't appear to be any real disadvantage to the 35VKR size bracket "Developer" but the larger capacity units are too inferior to the normal Aero VKR to justify any savings.

duckDecoy

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#2374816 13-Dec-2019 15:07

bfginger:

External condensate pumps are notorious for noise and poor reliability. If you've got a difficult installation situation you could get a cassette (ceiling) unit, which although being more expensive they should come with a condensate pump built in. Acoustic and efficiency technology in some cassette units is dated though.

The salesperson who installed our heatpump last year warned us off the cassette units, said they are noisy and for the 3 they installed last year all 3 were removed again due to the customer not being able to live with the noise. Just passing on what I was told.

New World

Shop on-line at New World now for your groceries (affiliate link).

kingdragonfly

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#2374826 13-Dec-2019 15:34

I never heard of a cassette unit, though I do remember one at a small office I worked at

Here's a link to people stumbling across this thread. Lots of manufacturers. I have no association with Mitsubishi

Mitsubishi Ceiling Mounted Heat Pumps

kingdragonfly

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#2375102 14-Dec-2019 07:39

Those cassette heat pumps seem about more 33% expensive as conventional ones. There design would be noisy too.

I'll see if someone can do a conventional one.

Cheers

bfginger

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#2377396 17-Dec-2019 23:33

duckDecoy:

bfginger:

External condensate pumps are notorious for noise and poor reliability. If you've got a difficult installation situation you could get a cassette (ceiling) unit, which although being more expensive they should come with a condensate pump built in. Acoustic and efficiency technology in some cassette units is dated though.

The salesperson who installed our heatpump last year warned us off the cassette units, said they are noisy and for the 3 they installed last year all 3 were removed again due to the customer not being able to live with the noise. Just passing on what I was told.

What brand were those units? I don't think they're inherently noisier but anything other than highwall models is going to be updated less often so you have to check specifications.

Going by the Panasonic brochures their cassettes can be rated quieter indoors than their highwalls in the 6-10kw brackets.