ASHP Install from hell Part 4 - Location - WEST or NORTH? What is best?
Background: The original survey had the Daikin Mono 16KW ASHP located on a West Facing back garden "Sun Trap" wall, located on the external wall of where the boiler used to be. After several more surveys the Installation Company Director came round and determined it should be on the North Wall (side of house).
I challenged the Installer on the following grounds:
1) The width of the North passage is very narrow so there is not much space for the exhaust
2) The Northern passage is cold, receiving no Sun.
3) Planning permission concerns/noise to neighbour concerns.
The installer said they had installed hundred of ASHP in those positions and never had a problem with any of the issues raised and would indemnify me against any planning permission come-backs. He said there was no other alternative location suitable. As these guys are MCS certified and a large company I could only accept what he was saying as an honest and accurate account. My remaining concern was the noise to the neighbour, however their closest window is >7 metres away and in winter they wouldn't have the windows open. If noise became an issue I could maybe erect a noise reducing fence and channel the air flow somehow.
The Pros to having it on the North Wall:
1) Out of sight on the side of the house which is not used for any access.
2) Shortish pipe run to the DHW Cylinder, approximately 4 metres of pipework (outside).
3) The passage is a wind tunnel which keeps an airflow across the ASHP, only on very still days is their not a breeze going through there.
4) The passage is sheltered from most of the wet weather.
The alternative was the West wall by the conservatory/Kitchen. My thoughts were that all the associated ASHP plumbing and controls would be installed where the Boiler used to be and the existing F&R 22mm could be used from that cupboard to the Rads and Cylinder. However the installer was looking at putting the cylinder in that cupboard as well so that would never fit.
Pros:
1) The ASHP would be in a sun trap location, being on the warmest spot in the garden.
2) The exterior pipework would be minimal with just the gap between HP & Wall being exposed.
3) The cupboard would fit the buffer, Backup heater pressure vessel and controls. The Controller would be located in a used room (the kitchen) rather than in an airing cupboard as is the case for the current setup on the North wall. I'm wondering whether a buffer and backup heater are even required!
4) existing F&R distribution pipework can be used.
5) it would give us back our space in the airing cupboard for sheets etc which we have lost in the current setup.
Cons:
1) Its visible and would be blowing on us at our outside table (in summer) - I'm not bothered about what it looks like and maybe it wont be on so much in the summer anyway? Outside air con?!
2) It's exposed. The fan would be full-on exposed to the westerly gales, if these are up at 50/60/70mph in the winter storms could this damage the unit? This is my biggest concern for this position.
3) The pipe run to the DHW Cylinder would be over the specified 10m in the Daikin manual. Not by much, its difficult to say how long the pipe run is as its all hidden, i would say 10-15 metres, but the run is all internal so there shouldn't be much heat loss along the way, the same heat loss existed when the boiler was there.
photos to follow, this website is having trouble uploading today.

Silly question perhaps, but did the installer give any reasons as to why they felt it's the only position available? Any expert worth the name should be able to back up their assertions with reasoning.
105 m2 bungalow in South East England
Mitsubishi Ecodan 8.5 kW air source heat pump
18 x 360W solar panels
1 x 6 kW GroWatt battery and SPH5000 inverter
1 x Myenergi Zappi
1 x VW ID3
Raised beds for home-grown veg and chickens for eggs
"Semper in excretia; suus solum profundum variat"
@majordennisbloodnok only that they couldn't fit everything in to the area on the West Side of the building where the boiler used to be. Another option briefly aired was to use the Garage for all the associated plumbing and cylinders, but i already have a full garage anyway so didnt want to lose more space and it is a detached garage away from the property so in my view the heat loss would be far greater. The decision to put it on the North side came very late, maybe 6-7 months are i engaged them! At that point i just wanted it over with as the Green Homes Grant voucher was expiring.
@derek-m well the HW Cylinder was another saga all by itself which nearly cancelled the install. The airing cupboard upstairs is not full height so its needs a short (or wide) cylinder. The first cylinder that turned up was too big so they had to go source elsewhere. Ended up with a Grant Monowave Indirect Heat Pump 150lts. This actually replaced the 125lts cylinder so I was getting a bit more water than before. Its borderline on capacity requirements but we never ran out under the old system as I have flow restrictors on taps and showers.
@derek-m thanks for the tip - the installation manual for the Daikin Cylinders should be able to point the installers in the right direction, maybe its the Options Kit that they have bought.
Any thoughts on the North versus West scenario?
Posted by: @saf1973@derek-m thanks for the tip - the installation manual for the Daikin Cylinders should be able to point the installers in the right direction, maybe its the Options Kit that they have bought.
Any thoughts on the North versus West scenario?
Hi,
As far as location is concerned, it is difficult to say without actually seeing the actual proposal. One thing that most manufacturers state is that the unit should not be located where it will be subject to strong winds at the exhaust side. The outdoor unit should also have as much space around it to ensure adequate airflow.
there are pros and cons of the outdoor unit being in sun or not. If it's in the sun it may be a bit more efficient because the air may be warmer. OTOH if it's in a sun trap it may make weather compensation a bit hit and miss as the outside temperature may not always vary in the same way as the heat loss from your house. An ASHP in the shade will be a bit more predictable.
As Derek says airflow is very more important.
My ASHP is in a north facing, sheltered spot with plenty airflow and seems fine.
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