We are trying to get an heat pump installed but have some issue with the positioning.
The only feasible location is the side of our house where we have 90cm of land before it becomes private footpath of the housing association but with public access. Attached photo, the position would be roughly where the bin on the right are.
Once the 1m boundary rule will be cancelled we would not need to apply for planning but Octopus our current quote is not willing to go ahead without speaking to the council.
Their concern is that we might freeze the path because of the colder air coming out the heat pump directly on the path.
We are waiting technical survey from Aira but we guess will result in the same issue.
Is there anyone that had similar issues or do you have any comments on the frozen path or suggestion? Would installing the heat pump on the wall above 2m be an option? Octopus will only install 30cm above the ground.
We don’t have space at the back of the property, and even placing it in the garden with long pipe underground is not an option as all the pipes of the current heating system are on the side of the house.
We are thinking of getting a survey done by a heat geek installer but the initial quote is higher than Ocotpus and Aira so we were bit taken back.
Hi @rikiarn, welcome here! Difficult one. A picture says 1000 words. There's some things jump out:
The proximity of the neighbouring property. Positioning the ASHP in an alleyway between two gable ends will amplify the noise levels, with two reflective opposing large surfaces. It's likely the noise level assessment test criteria at the neighbouring gable end window (and yours) under MCS 020 guide will not be met. ASHPs are quiet, but any noise in a confined location gets bounced around and amplified. Wall mounting the unit will only exacerbate the potential noise issue, and risk structural noise transmission into your property fabric through the supporting wall brackets. You might be on great terms with your neighbours, and they have no concerns at all, but they could move on and you could find new neighbours problematic and asking you to reduce the noise level from the ASHP, which in this location is incredibly challenging.
The public access to the footpath and risk of damage to the ASHP unit. I don't know how likely that is where you live, or whether it would concern you, but it's better if the location isn't publicly accessible, for obvious reasons. ASHPs are not cheap to buy or to repair if they get damaged.
The risk of the path freezing is a complete misnomer. The installers don't understand the psychrometrics of how an ASHP works. The cold air leaving the ASHP has very low temperature and humidity, as moisture has been removed from the air passing through the evaporator coil. The airstream will tend to dry the path where the air stream flows over it, not create frost or ice. The risk from ice is solely from the condensate caused when the unit is operating in lower temperatures and/or defrosting regularly. That needs to have a drain arrangement, either a soakaway under the unit or an insulated frost-protected pipe to a fresh water drain gulley, to prevent the water from pooling under the unit and re-freezing on the ground.
The 1m rule. Until changed, the rule is the rule. Unfortunately Local Authority planning departments have no discretion, and little common sense. It's a black and white binary decision for them. It either complies with current permitted development requirements, or it doesn't. In your case, and as the PD rules currently stand, it doesn't.
@rikiarn I agree with @allyfish that this is a difficult one. I spent ages contemplating locations for mine, mentally going through all the options (about 8 in total - with varying practicality) before settling on the one I chose. After some discussion with the boss I ended up with a location which I had previously dismissed, but am now very happy with!
If the alleyway really is the only option then towards one end and will help with escape both of noise and cold air (which you do not want to recirculate!) Raising it will help with the latter. @allyfish is also right that the PD rule hasn't changed yet and, until it does, its the rule.
Is there any value in posting a plan of your house and its neighbours in case someone can suggest an option you may have missed, or are you absolutely certain this is the only one? Sometimes looking at things from a different perspective helps. Whats the (physical) size, capacity and noise power from the ASHP or is this still TBD?
You can get anti-vandal cages for aircon units, if that is a potential issue. Certainly they aren't vandal proof, but do offer some protection.
Thank you for the welcome and the replies very helpful for us.
The location is unfortunately the only one feasible for us as the back of the house have essentially no room due to patio door and kitchen door. We would be also closer to our neighbour window and more issues for the noise levels.
@allyfish Our neighbour does not have any liveable space on that side as they have kitchen, stairs and landing and bathroom. The window is on their landing and the surveyors told us that would be enough to pass the sound test, would it not be the case? We have discuss the decision to have the heat pump there with our neighbour and they are supportive of it, I get obviously that the situation might change if they move out.
We have been told about the 1m rule but the installation would not be completed before it will get removed. In terms of vandalism the area is very quiet and the alley is mainly used by the resident in our housing complex and we all know each other.
I have seen that there are lot of heat pump cover that have ventilation to the side, and seen that are used in Scandinavian countries as well, would that potentially limit the noise as well? To be honest if placing a cover will give us the opportunity of removing our struggling gas boiler, I would be happy sacrifice a bit the efficiency of the pump. I also saw a video from Heat geek that covered the pump completely that did not have a massive reduction in efficiency
@JamesPa the one propose from Octopus is either the Cosy 6 or the daikin heat pump altherma 3 low capacity( 6kw), otherwise it's the 6kw from Aira. Top noise is around 62db. I tried measure it outside and the noise level drop to about 48 close the the neighbour wall.
Would the cold air coming out the heat pump have the potential to increase the neighbour heat loss? I received comments from another forum about that. There is regular airflow in the alley and I would have thought it will dissipate quickly the air coming out of the pump.
@allyfish Our neighbour does not have any liveable space on that side as they have kitchen, stairs and landing and bathroom. The window is on their landing and the surveyors told us that would be enough to pass the sound test, would it not be the case? We have discuss the decision to have the heat pump there with our neighbour and they are supportive of it, I get obviously that the situation might change if they move out.
Landing windows dont count so calcs are based on the nearest window to a liveable space
I have seen that there are lot of heat pump cover that have ventilation to the side, and seen that are used in Scandinavian countries as well, would that potentially limit the noise as well? To be honest if placing a cover will give us the opportunity of removing our struggling gas boiler, I would be happy sacrifice a bit the efficiency of the pump. I also saw a video from Heat geek that covered the pump completely that did not have a massive reduction in efficiency
Covers are an option but if the calcs say that its OK noise-wise then its not worth bothering. They are jolly expensive.
Would the cold air coming out the heat pump have the potential to increase the neighbour heat loss? I received comments from another forum about that. There is regular airflow in the alley and I would have thought it will dissipate quickly the air coming out of the pump.
In principle marginally yes, its like a cold wind blowing. But if the alley gets wind then, as you say, it will dissipate.
If octopus are willing to install it there and there really is no alternative location then Id be tempted to go for it. Its not ideal, but the world isn't ideal and one has to select from available options. Personally I would raise it off the ground, even if only by the 30cm Octopus will do, so cold air can fall away.
Planning is strictly an issue until the law changes. That said the enforcement action is to require you to remove it. Assuming the law does change you would be entirely within your rights to reinstate it immediately afterwards. The local authority know this and so, unless they have little better to do, are very unlikely to take action unless there is actually a complaint. If your neighbour seems amenable they wont complain. Is a complaint from the the housing association a risk?
This is probably one of those cases where it all depends on what the installer will do and your willingness to take a risk. If you want to play safe wait until the PD rules change.
This is an awkward problem which provides a taste of the challenges arising from the objective of decarbonising home heating (IMO all new-build nomes should be required to be heat pump ready even though the gov't stepped back from the requirement for them to be fitted with heat pumps in order to minimise the future conversion challenges).
My inclination would be to try to place the heat pump near the back corner of the house where there should be more air circulation. Heat pumps invariably create a cooler micro-climate around themselves which will be greatest when they were working hardest in cold weather when there's often minimal wind to move the cold air pocket created by the heat pump.
Let me add two further thoughts into the mix @rikiarn
1: An ASHP doesn't have to be at ground level. There are wall-mounting kits available, and some have optional condensate trays with an outlet which can be guided into a pipe.
2: Provided you don't block the airflow, you can make whatever sort of screening/cover you want.
This can operate as a noise-reduction strategy, using louvres, and also provide a platform on which to grow plants.
Neither of these is a ready-to-go solution to your space issue.
I'm merely wanting to broaden the discussion to better allow us to find a way forward for you.
Thank you for all your comments, they are really helpful for us. Octopus has now come back to us saying apparently that there no problem with the position of the heat pump near the path and willing to go ahead. We are a bit puzzled as the day before I had a conversation with the surveyor that has highlighted as major issue the freezing of the path caused by the blowing of the fan.
They are offering the cosy6 which I am not a particular fan, a bit for the efficiency, less than daikin, and for the orientation of the fan which might blow the air in people face, as the fan is tilted up and diagonally. A suggestion we received from a friend is to create some kind of fence/cover in front of the fan to further direct the air vertically. We still need to discuss this with Ocotpus if possible.
At the moment Ocotpus is only installing the daikin heat pump, which could be alternative to the cosy6, on wall but only 30cm high, but a cover/screen of some sort could mitigate the outgoing air.
We are waiting from a survey from Aira as well to understand if the see the situation differently.
I will keep this post updated as might be useful to other people in the same situation and really finding very helpful all your comments, thank you a lot.
Good update 🙂 Cosy 6 aka 'The Maddy D's Bin' has a inclined fan outlet, but the fan outlet is not a freezing risk anyway, that risk is only from condensate draining out of the unit and refreezing if not drained away. Be cautious with ideas to screen or fence around ASHPs, especially on the fan outlet side, they need unrestricted air movement close to the unit. There are products that can do this, but just be mindful of potentially solving one issue only to create another! In your proposed location any screening would have to be very close to the unit, and that could be problematical.
LA Permitted Development compliance is your responsibility, not the installer, so if the 1m from boundary rule cannot be complied with, that's at your risk.
Let me add two further thoughts into the mix @rikiarn
1: An ASHP doesn't have to be at ground level. There are wall-mounting kits available, and some have optional condensate trays with an outlet which can be guided into a pipe.
2: Provided you don't block the airflow, you can make whatever sort of screening/cover you want.
This can operate as a noise-reduction strategy, using louvres, and also provide a platform on which to grow plants.
Neither of these is a ready-to-go solution to your space issue.
I'm merely wanting to broaden the discussion to better allow us to find a way forward for you.
I have that exact bracket and condensate tray and i just bought anti vibration feet so i can remove this bracket from the wall. Its like car engine idling all around the house because of this bracket. Im building ledge up to heat pump and mounting on feet in January. I Wouldn't recommend this bracket to anybody.
@rikiarn I’m going to be really curious what Aria propose.
I’m not usually a fan of suspended heat pump installations, but judging by your photo, this could be a viable option for your setup, provided it’s mounted correctly with high-quality anti-vibration mounts and dampers. Proper mounting is key to minimising noise and vibration transmission, which can otherwise resonate through walls or structures.
The main consideration here is keeping the unit out of harm’s way. While you mentioned that vandalism isn’t a concern, there’s always the potential for accidental damage, be it from heavy storms or debris. Suspended installations can help mitigate these risks, particularly in areas prone to water pooling or flooding. I’m not sure if that’s a potential risk in that alley way.
