ashthekid Posted March 5, 2021 Share Posted March 5, 2021 Hi, I’m looking at installing a new air source heat pump into my conversion project but would like to know if anyone can provide any information regarding the distance it’s recommended to be located from the property itself. I was planning to have it positioned at the bottom of the garden which is approx 25m in length in a very narrow garden that is only 6m wide. And then it’s about 15m internally. So approx 40m in total in a completely straight line to the internal unit/setup. Is that ok? I don’t really have any outlet choice of location. It’s meant to be an LG air source heat pump going in. Link to comment Share on other sites More sharing options...
PeterW Posted March 5, 2021 Share Posted March 5, 2021 Would need to be 28 or even 32mm pipework and very well insulated. You’re probably talking 40-50 litres of water just in the pipework, it will take a fair while to get decent heat through to the house and cost a fair amount in insulated pipework. Link to comment Share on other sites More sharing options...
ashthekid Posted March 6, 2021 Author Share Posted March 6, 2021 That sounds expensive. So there is no set distance limit per say, it’s just a case of the further the distance the more heat loss there is and the more the air source heat pump has to work? Link to comment Share on other sites More sharing options...
rbw Posted March 6, 2021 Share Posted March 6, 2021 I asked a related question here:, thread might be useful to you @ashthekid My conclusion is that for my case this should be possible given the right type of insulating pile. Google Mibec insulated pipe - that’s likely what I’ll end up using. Admittedly this will be more like 20m but if you look at the spec the heat loss doesn’t seem too bad. Link to comment Share on other sites More sharing options...
ProDave Posted March 6, 2021 Share Posted March 6, 2021 What is the reason for wanting it so far from the house? Link to comment Share on other sites More sharing options...
ashthekid Posted March 6, 2021 Author Share Posted March 6, 2021 To be honest it’s not really a choice at it’s the only option. With the garden being so narrow, only 6m wide, I cannot have the unit just sat on the patio terrace which is directly connected to our living room. It makes sense to have it at the end where we will park our cars. Sadly there is no gas in our village so some sort of electric heating for UFH and HW is needed that is going to be cost effective to run as the ground floor sqm is approx 240sqm. Air Source seemed the most efficient. I don’t want to consider LPG or oil. I will check out that Mibec insulated pipe. Is that the best on the market for what I am trying to achieve? Link to comment Share on other sites More sharing options...
PeterW Posted March 6, 2021 Share Posted March 6, 2021 2 hours ago, ashthekid said: That sounds expensive. So there is no set distance limit per say, it’s just a case of the further the distance the more heat loss there is and the more the air source heat pump has to work? Yep pretty much. Long time to get heat as pumps don’t run that fast and the larger the pipe the lower the flow. Would suggest a buffer tank in the house too. Link to comment Share on other sites More sharing options...
ProDave Posted March 6, 2021 Share Posted March 6, 2021 An alternative suggestion is smaller pipes on the long run, accept it will kill the flow rate and might upset the ASHP and counter that by adding an extra circulation pump at the house end to help push the water at an acceptable rate. Link to comment Share on other sites More sharing options...
willbish Posted March 6, 2021 Share Posted March 6, 2021 1 hour ago, ashthekid said: I will check out that Mibec insulated pipe. Is that the best on the market for what I am trying to achieve? Also consider using Upanor Ecoflex insulated pipe. Thermo twin is the type you need. It's definitely not cheap though. I bought an offcut and put under my foundation. Link to comment Share on other sites More sharing options...
jack Posted March 6, 2021 Share Posted March 6, 2021 50 minutes ago, ProDave said: An alternative suggestion is smaller pipes on the long run, accept it will kill the flow rate and might upset the ASHP and counter that by adding an extra circulation pump at the house end to help push the water at an acceptable rate. Higher pressure pump = higher flow rate through smaller pipework. Higher friction losses but possibly lower heat loss through smaller surface area of the pipe. Also, smaller pipework means less fluid, which could add up on a very long run. Link to comment Share on other sites More sharing options...
ashthekid Posted March 6, 2021 Author Share Posted March 6, 2021 So essentially I need to look at a heat pump with high pressure and then use the smaller(25mm @ £25 per meter Mircroflex DUO insulated PEX pipe) installed pipe run option to increase the flow rate and minimise heat loss. Have a large buffer tank internally in the “boiler room” with maybe a backup immersion heater in case the ASHP breaks down or needs a bit of extra oomph when we have a few extra people staying with us. Does that sound about right? Its an LG Therma V ASHP that is contracted to go in. According to the brochure provided, a split system allows for the external unit to be located upto 50m away. Link to comment Share on other sites More sharing options...
RichardL Posted March 6, 2021 Share Posted March 6, 2021 Any milage in mounting the heat pump on a wall - you said potential space on the 'car side' - what if the pump were 5 or 6' up on that wall? I suspect you've thought through all possible locations - but perhaps another pair of eyes will find options/thoughts if you could share a siteplan? Link to comment Share on other sites More sharing options...
ashthekid Posted March 6, 2021 Author Share Posted March 6, 2021 Sadly we are fenced in from all sides. It’s a narrow L-shaped garden with car access at the very end of the L. I’ve had a few people look at it and say it’s the only option. Link to comment Share on other sites More sharing options...
PeterW Posted March 6, 2021 Share Posted March 6, 2021 8 hours ago, ashthekid said: Its an LG Therma V ASHP that is contracted to go in. According to the brochure provided, a split system allows for the external unit to be located upto 50m away. Split system ..?? That changes the whole game ..!! That needs refrigerant pipework so you need a duct not water pipework. Ideally it’s an open duct so you can drop the insulated runs in (can’t just bury them). The engineer will have to install insulated copper refrigerant lines and they need to be installed carefully and you can’t pull them in easily so it’s going to be expensive. And these units can be noisy internally. Any reason for choosing a split ..?? Link to comment Share on other sites More sharing options...
ashthekid Posted March 7, 2021 Author Share Posted March 7, 2021 The split system seemed appealing given the 50m distance it can go upto, the external box is also smaller in the garden. The internal unit will be in its own boiler room in the house so noise wise it should hopefully be contained. I’ve not heard of people complaining about the noise on split systems to be honest. I hadn’t factored in the pipe work being dramatically different on the split system but if it’s refrigerant type then that is slightly more complicated to run I’m assuming. Achievable for sure but just more technical and delicate to get right so it’s successful and long lasting. It won’t be buried externally, would probably run alongside/on top of whatever we have against the fence side. Link to comment Share on other sites More sharing options...
TonyT Posted March 7, 2021 Share Posted March 7, 2021 I’ve buried spilt AC pipework, 2x100mm ducts just to make installation easy.. Ducts pop up externally above ground level and are sealed to prevent water ingress. 4 years and counting with no issues. AC installer had no problems carrying out the set up. Link to comment Share on other sites More sharing options...
PeterW Posted March 7, 2021 Share Posted March 7, 2021 51 minutes ago, ashthekid said: I’ve not heard of people complaining about the noise on split systems to be honest. Start by reading this ...!! And they move the heat exchanger unit into the house so can be noisy. 51 minutes ago, ashthekid said: It won’t be buried externally, would probably run alongside/on top of whatever we have against the fence side. OK so you need to protect it somehow as you need to use UV stable external insulation and also need to stop the local wildlife picking at it. 52 minutes ago, ashthekid said: the external box is also smaller in the garden. What size are you looking at ..?? You can get vertical fan units that are smaller than their standard equivalent as they pack more fins into the box - the air/fan coil is the issue with size. Link to comment Share on other sites More sharing options...
Jde00 Posted March 13, 2021 Share Posted March 13, 2021 (edited) Sorry to sequester the topic but I’d like to move my nibe F2040 further down the garden. Would Moving the ASHP 7-8m down the garden be a big headache? Edited March 13, 2021 by Jde00 Link to comment Share on other sites More sharing options...
ashthekid Posted March 13, 2021 Author Share Posted March 13, 2021 Maybe I will insist on the insulated pipework to be buried for safety and additional natural insulation. There maybe a couple of bends when it reaches the property so that it then runs inside the large cavity gap we have had to create for the property. In terms of size, I believe if we do go for the split system we would need the 12-16Kw 950x1380x330. It’s heating underfloor space of 240sqm on the ground floor, then 11 radiators upstairs plus hot water. That system should cover that shouldn’t it? Link to comment Share on other sites More sharing options...
TonyT Posted March 13, 2021 Share Posted March 13, 2021 Armaflex insulation for exterior use when it’s likely to be exposed to UV Link to comment Share on other sites More sharing options...
ashthekid Posted March 13, 2021 Author Share Posted March 13, 2021 So Armaflex if not buried but if I can bury it it’s best to create a duct and then lay another type inside that? Link to comment Share on other sites More sharing options...
TonyT Posted March 13, 2021 Share Posted March 13, 2021 Cheaper insulation is climaflex. It’s not UV stabilised but if it’s in a duct it’s not getting UV so your shout. make sure the ducts are sealed. proprietary duct sealing kits such as rise. or expanding foam below the lip of the duct and then a weak mortar mix to infill 1 Link to comment Share on other sites More sharing options...
puntloos Posted July 31, 2021 Share Posted July 31, 2021 2 questions if I may: 1/ If you go into/under the foundation of a house with such heat pipes coming from a monobloc, what happens if the pipe breaks/freezes while under the house? Knock the house down and start over? 2/ How are ASHPs put in a garden, do you give them a concrete foundation? Or just stick a pole in the ground somehow? And how deep would you bury the lines at 1m? 1.5? 30cm? Link to comment Share on other sites More sharing options...
Dave Jones Posted July 31, 2021 Share Posted July 31, 2021 don't forget your neighbours, how far will it be from neighbouring buildings ? Expensive to rip it out when they complain about the constant noise. Link to comment Share on other sites More sharing options...
SteamyTea Posted July 31, 2021 Share Posted July 31, 2021 3 hours ago, puntloos said: If you go into/under the foundation of a house with such heat pipes coming from a monobloc, what happens if the pipe breaks/freezes while under the house? Knock the house down and start over It is usual to have flexible pipes from the monobloc, the manufacturer specifies the length of them. This is to stop vibration from travelling along solid pipework. So it is usual to fit them in a service channel/duct. 3 hours ago, puntloos said: How are ASHPs put in a garden, do you give them a concrete foundation Yes. Link to comment Share on other sites More sharing options...
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