DragsterDriver Posted July 31, 2021 Share Posted July 31, 2021 I’m planning to have all my ‘plant’ in the detached garage and ducted to the house maybe 6m away. From asking around that’s fine using ducts and the correct insulated pipe work. Link to comment Share on other sites More sharing options...
puntloos Posted July 31, 2021 Share Posted July 31, 2021 7 hours ago, Dave Jones said: 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. The plan is in the far corner of my plot (red, new house in blue) which is an area of a bunch of sheds. Perhaps straight behind the two big sheds might be mildly better but then I Imagine installing the stuff will basically kill most of the laurel hedge (the huge green one) which would be a pity, not to mention I imagine (?) an ASHP will have some trouble 'breathing' in a hedge, and the hedge might even react poorly to the different 'climate' either. 7 hours ago, SteamyTea said: It is usual to have flexible pipes from the monobloc, the manufacturer specifies the length of them. Ah makes sense thx. 7 hours ago, SteamyTea said: This is to stop vibration from travelling along solid pipework. So it is usual to fit them in a service channel/duct. Link to comment Share on other sites More sharing options...
SteamyTea Posted July 31, 2021 Share Posted July 31, 2021 (edited) 2 hours ago, puntloos said: I Imagine installing the stuff will basically kill most of the laurel hedge (the huge green one) which would be a pity, not to mention I imagine (?) an ASHP will have some trouble 'breathing' in a hedge, and the hedge might even react poorly to the different 'climate' either. As long as it is not totally overgrown, and you have a metre and half diameter circle around it, it should not be a problem. Any air that is cooled is soon dispersed, and it only comes out a little bit lower than ambient. I would be more concerned about losses though the pipe runs, as well as electrical losses depending on cable sizing and length. A cubic metre of air has a mass of about 1.25 kg, and a specific heat capacity of around 1 kJ/kg.K, which is 0.0002778 kWh. So if that cubic metre of air is cooled by 5K (or °C), you get 0.00173625 kWh of energy. To get a kWh out of that air, you need to shift 575.95 kg of air, or about 720 cubic metres. Sounds a lot, but is not in reality. About a third of what my car sucks in though the air intake in my car when I am doing 70 MPH. Edited July 31, 2021 by SteamyTea Link to comment Share on other sites More sharing options...
mjc55 Posted August 8 Share Posted August 8 As no one has posted for a while and given that we will not be in a position to install ASHP until next year I thought that I would resurrect this thread! Has much moved on in ASHP world? I ask as I am thinking where to position ours and currently the obvious position would be on the outside wall immediately outside the "plant room". Neighbours on that side do not have any real habitable rooms facing us on that side and there would be around 3m (ish) between us and the fence anyway. Interestingly having a quick google brought one site up that in one breath stated that it shouldn't be on South facing wall and then it should be (???). The plant room is on the South elevation. The thing I am slightly nervous about is proximity to our bedroom. Would be around 5-6m to (clerestory) window in bedroom (single storey property) and although we are aiming for passive I am certain that in the warmer months the window will end up open (would be better to not follow up in this thread about the wisdom of doing this btw!) There would be room on site to put the ASHP unit forward of the house (to one side of driveway) within around 5-10 m of the plant room so this is one possibility I might explore. The other thing I guess is that the more I read the more it seems that ASHP technology has moved on recently so maybe noise isn't as much of an issue as it used to be? As always, thanks for all responses. Link to comment Share on other sites More sharing options...
joe90 Posted August 8 Share Posted August 8 If your worried about noise to your bedroom, or neighbours, you could time it to not come on at night! 1 Link to comment Share on other sites More sharing options...
SteamyTea Posted August 8 Share Posted August 8 (edited) Not much has changed with heat pump technology in the last 100+years, just gentle refinements. The two main changes have been to use refrigerant gasses that have lower global warming potential, and, and this is really the main change, better speed control of the pumps and fans. It is this control that allows a heat pump to be run quietly. They do this by matching the airflow to the power delivery. The days of a heat pump being either off (silent) or full power (noisy) are well over for domestic units. And as @joe90 says, time it to only heat water during the day, it will be cheaper to run, especially if you have PV. (Noise cancelling be overrated, the council are resurfacing a road 30m from my open bedroom window between 7PM and 2AM, I sleep though it) Edited August 8 by SteamyTea 2 Link to comment Share on other sites More sharing options...
JohnMo Posted August 8 Share Posted August 8 1 hour ago, mjc55 said: the more I read the more it seems that ASHP technology has moved on recently No real changes since the inverter was used on ASHPs. Only real change that is occurring very slowly is a move from a home full of thermostats and on or off heating schedules. And a required buffer that can clobber CoP when not designed correctly - they rarely are. Best thing you can do for noise. Size the heat pump really well, so it just ticks away. Starting can be the most noisy because the frequency is always moving and there can be some clicks as valve find position. Normal running is just about silent from a metre away. Switching off and or setbacks will cause the heat pump to run at full load for an extended period as it tries to heat the property at the end of the off or setback period. So make more noise than just ticking away. 1 Link to comment Share on other sites More sharing options...
MikeSharp01 Posted August 9 Share Posted August 9 11 hours ago, JohnMo said: a move from a home full of thermostats and on or off heating schedules. How does this relate to the need once / twice a day to run up the DHW temp if PV / Solar not available? Link to comment Share on other sites More sharing options...
JohnMo Posted August 9 Share Posted August 9 53 minutes ago, MikeSharp01 said: How does this relate to the need once / twice a day to run up the DHW temp if PV / Solar not available? Not seeing any mention of DHW or solar in the thread? So a bit confused That wasn't the question I was referring too. Below is that question. 14 hours ago, mjc55 said: more I read the more it seems that ASHP technology has moved on recently Link to comment Share on other sites More sharing options...
Marvin Posted August 9 Share Posted August 9 (edited) Hi @mjc55 We swapped our bottled gas boiler for our ASHP. The Boiler made more noise than the ASHP does. Yes we can hear it in the depths of winter but you have to be listening out for it. It sits on our flat roof 4 meters from our bedroom. Yes we wondered and wondered about the noise before we installed it. Best I can suggest is to find someone with an ASHP and ask if you can listen t it when its on. As @SteamyTea comments above "better speed control of the pumps and fans" has been improved with the result being a quieter more efficient ASHP: AS I understand it before it was either full on or full off. now it slowly increases and decreases. (think of this like a car would react) Being near a window the result would depend on the positions. Ours blows away from our windows and is no problem. However, I would suggest you act with great caution about positioning the ASHP. A quick decision that you live with for a long time. As a rule of thumb, the nearer the ASHP to the building thermal envelope the more efficient it will run. The more free air about it the easier it will work. The shorter the distance between the ASHP and the plant room the more efficient. The thicker and more resistant to thermal change the pipe insulation the more efficient. Inside and outside our property we have used the thickest insulation we could on the primary pipes (pipes from ASHP to plant room). If you site the ASHP away from the building where are you thinking of installing the pipes? Difficult to make suggestions without knowing your layout. Obviously any position you choose and install at, within MCS rules and connected properly, will work, its only the efficiency that would concern me. When you add up all the little details that are not the most efficiently completed on a system bear in mind, the further away the temperature of the water leaving the ASHP compared to the temperature of the outside air, the less efficient it will run. With an ASHP, low and slow wins the day! Good luck Marvin This is a rough example of the efficiency curve: Edited August 9 by Marvin further thought 1 Link to comment Share on other sites More sharing options...
SteamyTea Posted August 9 Share Posted August 9 6 hours ago, Marvin said: think of this like a car would react Not a teenagers car, or Vespa though. Link to comment Share on other sites More sharing options...
MikeSharp01 Posted August 9 Share Posted August 9 12 hours ago, JohnMo said: Not seeing any mention of DHW or solar in the thread? So a bit confused Sorry. What I meant was that the smooth continuous operation gets interrupted by the demand for DHW so that needs to be factored in - does higher temperature operation, or changes to from, impact noise levels. Link to comment Share on other sites More sharing options...
JohnMo Posted August 9 Share Posted August 9 54 minutes ago, MikeSharp01 said: Sorry. What I meant was that the smooth continuous operation gets interrupted by the demand for DHW so that needs to be factored in - does higher temperature operation, or changes to from, impact noise levels. It should simply transition from heating to DHW heating, but depending on some heat pump settings, the load and noise will slowly increase as temperature increases. But even then it's not noisy. Then depending on the volume of water between the heat pump and diverter valve, and the target flow temperature, it may just transition back to heating or take some time off. Mine switches off for half hour or so. Link to comment Share on other sites More sharing options...
dpmiller Posted August 10 Share Posted August 10 ours goes through a phased shutdown, delays to allow the valve to move over, then starts back up; ramping up as the DHW tank heats Link to comment Share on other sites More sharing options...
Dave Jones Posted August 10 Share Posted August 10 we mounted ours on the plant room weall (1st floor), its silent as in impossible to know ifi its working or not when in the plant room. Link to comment Share on other sites More sharing options...
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