Decentralised MVHR to solve damp stuffy room
Discussion
Hi all,
Planning on putting a decentralised mvhr system in our master bedroom (basically a fancy pants extraction fan that recovers some of the heat from exhausted air and uses it to heat incoming air). The reason behind this plan is that the layout of the house (a bungalow) is a bit weird having been added to over the years.
The master bedroom is at one end of a corridor and tends to suffer from what I’d describe as ‘dead air’ – even with the window open (not ideal in winter as the house is already pretty cold) – and is normally quite stuffy. It is also at a fairly permanent state of high humidity – there are (seemingly) no obvious leaks in any plumbing or wet patches so I’m assuming it’s because there are two adults (and a toddler depending how the night goes!) sleeping in there. Currently run a dehumidifer in there which has stopped any mould but is fairly noisy.
I’m hoping the dMVHR system will make the room less stuffy and less humid. The system I’m thinking of is a Prana one from ecostream (https://ecostream.org.uk/recuperator-prana-210g-erp-pro-mini/). Ecostream will install for a few hundred quid (whilst I could do this, I’m not keen on drilling at 21cm dia hole in my wall and ensuring that it’s slightly sloping.
Anyone have experience of doing this kind of thing? Good idea / terrible idea?
In my mind I’d ideally install a PIV system near the room but there is a storage room in the loft above that prohibits this. I’m reluctant to drop 6k on a full MVHR system. I’ve contacted ecostream but they don’t seem great at recommending solutions / answering questions.
House layout below.
Planning on putting a decentralised mvhr system in our master bedroom (basically a fancy pants extraction fan that recovers some of the heat from exhausted air and uses it to heat incoming air). The reason behind this plan is that the layout of the house (a bungalow) is a bit weird having been added to over the years.
The master bedroom is at one end of a corridor and tends to suffer from what I’d describe as ‘dead air’ – even with the window open (not ideal in winter as the house is already pretty cold) – and is normally quite stuffy. It is also at a fairly permanent state of high humidity – there are (seemingly) no obvious leaks in any plumbing or wet patches so I’m assuming it’s because there are two adults (and a toddler depending how the night goes!) sleeping in there. Currently run a dehumidifer in there which has stopped any mould but is fairly noisy.
I’m hoping the dMVHR system will make the room less stuffy and less humid. The system I’m thinking of is a Prana one from ecostream (https://ecostream.org.uk/recuperator-prana-210g-erp-pro-mini/). Ecostream will install for a few hundred quid (whilst I could do this, I’m not keen on drilling at 21cm dia hole in my wall and ensuring that it’s slightly sloping.
Anyone have experience of doing this kind of thing? Good idea / terrible idea?
In my mind I’d ideally install a PIV system near the room but there is a storage room in the loft above that prohibits this. I’m reluctant to drop 6k on a full MVHR system. I’ve contacted ecostream but they don’t seem great at recommending solutions / answering questions.
House layout below.
Just to say Gosforth Handyman has just installed one of these - as in just, so no long term review about it - excuse the clickbait title though..
https://www.youtube.com/watch?v=WoLG6q1Tfgs
https://www.youtube.com/watch?v=WoLG6q1Tfgs
Thanks - much cheaper unit than the Prana....
The restoration couple have also done a video on it. At the moment i'm planning on taking a punt. Tho I do sort of wonder if I should do a whole house mvhr - most of the windows don't have vents on them. Bigger project than I want though really.
The restoration couple have also done a video on it. At the moment i'm planning on taking a punt. Tho I do sort of wonder if I should do a whole house mvhr - most of the windows don't have vents on them. Bigger project than I want though really.
If the rest of the house is not damp, I would be tempted to just do a single room MVHR. Simpler install, fairly quick, uses less power than a whole house system.
However, if you are struggling elsewhere in the house then I would consider a multi-room unit. I bought a used MVHR for a 3 bedroom house - the need for insulated ducting, draining of the unit, placing of the unit, the way of trying to get the shortest duct run to cover warm rooms and get the heat to cooler rooms - I decided it was not for me, and gave it to a friend who has a warm damp kitchen with a large open door to their damp living room, and right beside the kitchen is a "boiler room" with power, water drains, sound insulation, space and also a bedroom on another wall that needed fresh, warm, dry air.
However, if you are struggling elsewhere in the house then I would consider a multi-room unit. I bought a used MVHR for a 3 bedroom house - the need for insulated ducting, draining of the unit, placing of the unit, the way of trying to get the shortest duct run to cover warm rooms and get the heat to cooler rooms - I decided it was not for me, and gave it to a friend who has a warm damp kitchen with a large open door to their damp living room, and right beside the kitchen is a "boiler room" with power, water drains, sound insulation, space and also a bedroom on another wall that needed fresh, warm, dry air.
Will it be much quieter than the dehumdifier?
It might be worth considering the whole house in some way.
How warm and humid does the rest of the house tend to be at night?
You might find a Drimaster type system would work for you if you could make sure most of the air is leaving via the bedroom window being open a crack.
That might require a draught under the door from the hall.
We have slightly similar issues, we've made an improvement by better insulation in that now the great majority of heat which leaves our room is leaving as warm air via the window, instead of as heat via the ceiling.
Last time I did the maths on an MVHR unit, it was cheaper to just extract air and use gas for heating than to recycle the heat via MVHR.
That's partly because the outdoors here in the South West can be humid and warm-ish from the sea.
The other thing is to consider the humidity of the house as a whole, Make sure your cooking and shower etc are not adding to the humidity 'baseline'.
I have tinnitus and fan noise does my head in sometimes so I am biased!
I am interested in MVHR though, it's becoming more sensibly priced and might work for us, just not in my bedroom, so do please keep us informed.
It might be worth considering the whole house in some way.
How warm and humid does the rest of the house tend to be at night?
You might find a Drimaster type system would work for you if you could make sure most of the air is leaving via the bedroom window being open a crack.
That might require a draught under the door from the hall.
We have slightly similar issues, we've made an improvement by better insulation in that now the great majority of heat which leaves our room is leaving as warm air via the window, instead of as heat via the ceiling.
Last time I did the maths on an MVHR unit, it was cheaper to just extract air and use gas for heating than to recycle the heat via MVHR.
That's partly because the outdoors here in the South West can be humid and warm-ish from the sea.
The other thing is to consider the humidity of the house as a whole, Make sure your cooking and shower etc are not adding to the humidity 'baseline'.
I have tinnitus and fan noise does my head in sometimes so I am biased!
I am interested in MVHR though, it's becoming more sensibly priced and might work for us, just not in my bedroom, so do please keep us informed.
House tends to be quite stuffy and humid (I believe this is a thing with bungalows as you don't get the convection currents that normally exist in a two story house - I think our H shape lay out doesn't help either - dead ends). If it weren't for the room labelled 'playroom' (aka crap store) above the bedroom i'd probably just put in a couple of PIV units and be done with it.
I basically down to three options...
1) Single room MVHR - if it works well might shove another one in the other end of the house
2) Single room MVHR + a PIV unit near ish the front door (I have had the soffits done recently and they're now ventilated all the way around - does still have the bitumin type stuff under the tiles tho)
3) DIY a whole house MVHR system. It's not *that* much more than the posh single room mvhr + installation, and doesn't result in a 200mm hole in my wall. It would be 'relatively' easy to fit as it's a bungalow.
At the moment i'm erring towards option 3, tho I do have a lot of other projects that i'm meant to be doing for the wife! The other concern with 3) is that i have 5kw wood burner in the lounge, and have read some things suggesting that it's a terrible idea. Tho those tend to be with sealed houses, and I don't think we are that well sealed.
I'm not expecting this to save me money, more to freshen the atmoshere and maybe take the edge off just forcing cold air in.
I basically down to three options...
1) Single room MVHR - if it works well might shove another one in the other end of the house
2) Single room MVHR + a PIV unit near ish the front door (I have had the soffits done recently and they're now ventilated all the way around - does still have the bitumin type stuff under the tiles tho)
3) DIY a whole house MVHR system. It's not *that* much more than the posh single room mvhr + installation, and doesn't result in a 200mm hole in my wall. It would be 'relatively' easy to fit as it's a bungalow.
At the moment i'm erring towards option 3, tho I do have a lot of other projects that i'm meant to be doing for the wife! The other concern with 3) is that i have 5kw wood burner in the lounge, and have read some things suggesting that it's a terrible idea. Tho those tend to be with sealed houses, and I don't think we are that well sealed.
I'm not expecting this to save me money, more to freshen the atmoshere and maybe take the edge off just forcing cold air in.
I had the walls cavity insulated last winter, checking with my thermal camera doesn't show any cold spots. One issue is that in the plan the bit labelled bedroom 2 and principal bedroom has 1990s cavity wall insulation (looked like fibre glass wadding when i shoved a small camera in there) isn't as good as the insulation i've had pumped in elsewhere. The main issue is that that layout means that pretty much all walls are external walls - it's like it's been optimised for external wall area for internal area!
ewanjp said:
Hi all,
Planning on putting a decentralised mvhr system in our master bedroom (basically a fancy pants extraction fan that recovers some of the heat from exhausted air and uses it to heat incoming air). The reason behind this plan is that the layout of the house (a bungalow) is a bit weird having been added to over the years.
The master bedroom is at one end of a corridor and tends to suffer from what I’d describe as ‘dead air’ – even with the window open (not ideal in winter as the house is already pretty cold) – and is normally quite stuffy. It is also at a fairly permanent state of high humidity – there are (seemingly) no obvious leaks in any plumbing or wet patches so I’m assuming it’s because there are two adults (and a toddler depending how the night goes!) sleeping in there. Currently run a dehumidifer in there which has stopped any mould but is fairly noisy.
I’m hoping the dMVHR system will make the room less stuffy and less humid. The system I’m thinking of is a Prana one from ecostream (https://ecostream.org.uk/recuperator-prana-210g-erp-pro-mini/). Ecostream will install for a few hundred quid (whilst I could do this, I’m not keen on drilling at 21cm dia hole in my wall and ensuring that it’s slightly sloping.
Anyone have experience of doing this kind of thing? Good idea / terrible idea?
In my mind I’d ideally install a PIV system near the room but there is a storage room in the loft above that prohibits this. I’m reluctant to drop 6k on a full MVHR system. I’ve contacted ecostream but they don’t seem great at recommending solutions / answering questions.
House layout below.
Hi can I ask what you ended up deciding and any conclusions please?Planning on putting a decentralised mvhr system in our master bedroom (basically a fancy pants extraction fan that recovers some of the heat from exhausted air and uses it to heat incoming air). The reason behind this plan is that the layout of the house (a bungalow) is a bit weird having been added to over the years.
The master bedroom is at one end of a corridor and tends to suffer from what I’d describe as ‘dead air’ – even with the window open (not ideal in winter as the house is already pretty cold) – and is normally quite stuffy. It is also at a fairly permanent state of high humidity – there are (seemingly) no obvious leaks in any plumbing or wet patches so I’m assuming it’s because there are two adults (and a toddler depending how the night goes!) sleeping in there. Currently run a dehumidifer in there which has stopped any mould but is fairly noisy.
I’m hoping the dMVHR system will make the room less stuffy and less humid. The system I’m thinking of is a Prana one from ecostream (https://ecostream.org.uk/recuperator-prana-210g-erp-pro-mini/). Ecostream will install for a few hundred quid (whilst I could do this, I’m not keen on drilling at 21cm dia hole in my wall and ensuring that it’s slightly sloping.
Anyone have experience of doing this kind of thing? Good idea / terrible idea?
In my mind I’d ideally install a PIV system near the room but there is a storage room in the loft above that prohibits this. I’m reluctant to drop 6k on a full MVHR system. I’ve contacted ecostream but they don’t seem great at recommending solutions / answering questions.
House layout below.
Our 250 yr old barn conversion has a layout with similarities and similar issues with high humidity (around 70%) with a few signs of impact here and there.
House is well sealed, due to being on a high hill over 1000ft and not far south of the Scottish border. It's cold and windy up here at times. We've a 5kW multi fuel burner in the lounge, oil fired heating (amazing performance) and no trickle vents. Just an extractor on the kitchen and an extractor in our ensuite, 25m away, opposite end of the house.
We're venting manually with windows at the moment.
Am going to get the rads automated with WiFi TRVs and am thinking about options to improve humidity levels. Any advice would be much appreciated!
Rob-u50pm said:
ewanjp said:
Hi all,
Planning on putting a decentralised mvhr system in our master bedroom (basically a fancy pants extraction fan that recovers some of the heat from exhausted air and uses it to heat incoming air). The reason behind this plan is that the layout of the house (a bungalow) is a bit weird having been added to over the years.
The master bedroom is at one end of a corridor and tends to suffer from what I’d describe as ‘dead air’ – even with the window open (not ideal in winter as the house is already pretty cold) – and is normally quite stuffy. It is also at a fairly permanent state of high humidity – there are (seemingly) no obvious leaks in any plumbing or wet patches so I’m assuming it’s because there are two adults (and a toddler depending how the night goes!) sleeping in there. Currently run a dehumidifer in there which has stopped any mould but is fairly noisy.
I’m hoping the dMVHR system will make the room less stuffy and less humid. The system I’m thinking of is a Prana one from ecostream (https://ecostream.org.uk/recuperator-prana-210g-erp-pro-mini/). Ecostream will install for a few hundred quid (whilst I could do this, I’m not keen on drilling at 21cm dia hole in my wall and ensuring that it’s slightly sloping.
Anyone have experience of doing this kind of thing? Good idea / terrible idea?
In my mind I’d ideally install a PIV system near the room but there is a storage room in the loft above that prohibits this. I’m reluctant to drop 6k on a full MVHR system. I’ve contacted ecostream but they don’t seem great at recommending solutions / answering questions.
House layout below.
Hi can I ask what you ended up deciding and any conclusions please?Planning on putting a decentralised mvhr system in our master bedroom (basically a fancy pants extraction fan that recovers some of the heat from exhausted air and uses it to heat incoming air). The reason behind this plan is that the layout of the house (a bungalow) is a bit weird having been added to over the years.
The master bedroom is at one end of a corridor and tends to suffer from what I’d describe as ‘dead air’ – even with the window open (not ideal in winter as the house is already pretty cold) – and is normally quite stuffy. It is also at a fairly permanent state of high humidity – there are (seemingly) no obvious leaks in any plumbing or wet patches so I’m assuming it’s because there are two adults (and a toddler depending how the night goes!) sleeping in there. Currently run a dehumidifer in there which has stopped any mould but is fairly noisy.
I’m hoping the dMVHR system will make the room less stuffy and less humid. The system I’m thinking of is a Prana one from ecostream (https://ecostream.org.uk/recuperator-prana-210g-erp-pro-mini/). Ecostream will install for a few hundred quid (whilst I could do this, I’m not keen on drilling at 21cm dia hole in my wall and ensuring that it’s slightly sloping.
Anyone have experience of doing this kind of thing? Good idea / terrible idea?
In my mind I’d ideally install a PIV system near the room but there is a storage room in the loft above that prohibits this. I’m reluctant to drop 6k on a full MVHR system. I’ve contacted ecostream but they don’t seem great at recommending solutions / answering questions.
House layout below.
Our 250 yr old barn conversion has a layout with similarities and similar issues with high humidity (around 70%) with a few signs of impact here and there.
House is well sealed, due to being on a high hill over 1000ft and not far south of the Scottish border. It's cold and windy up here at times. We've a 5kW multi fuel burner in the lounge, oil fired heating (amazing performance) and no trickle vents. Just an extractor on the kitchen and an extractor in our ensuite, 25m away, opposite end of the house.
We're venting manually with windows at the moment.
Am going to get the rads automated with WiFi TRVs and am thinking about options to improve humidity levels. Any advice would be much appreciated!
We use a dehumidifier, but humidity is only part of the issue.
If I was going to seriously refurb the current house, I'd be looking at MVHR and/or aircon, these things are much cheaper than they used to be.
The point would be fresh air, not just dried stale air, and moving excess heat from some rooms and using it to warm others.
But for £200, a dehumidifier is a good start.
If I was going to seriously refurb the current house, I'd be looking at MVHR and/or aircon, these things are much cheaper than they used to be.
The point would be fresh air, not just dried stale air, and moving excess heat from some rooms and using it to warm others.
But for £200, a dehumidifier is a good start.
J6542 said:
As an instant solution, go to Screwfix and buy a £150 dehumidifier, it will easily extract 2 litres a day if your readings are so high. Then you can look into more long term solutions.
Yes and for the long term get some Aqara temp/humidity sensorsCould be your ground levels are too high / leaks / impermeable materials etc etc
OP here. Open question what we do about it. I took the advice and got a dehumidifier which has solved the immediate problem. Long term I still plan to fit a decentralised MVHR. Main thing putting me off is how to go through the wall (needs a 170mm hole most of the time) - core drill company wanted 400 quid and would have sprayed water everywhere. I have subsequently realised I could just use my SDS and drill a circle of holes which means it's back on my long list of jobs. This video has given me a little pause however.... https://youtu.be/zSxyUFLwFbc?si=OTnaI6gYfoF3-CFE
robemcdonald said:
My issue with that “MVHR” is there doesn’t appear to be any provision for bypassing the heat exchanger, so you’ll only ever be able to supply tempered air into the habitable room. This might be an issue in the summer time especially when it’s potentially cooler outside than in.
A good point, but I think the place I stayed in Denmark had some arrangement of flap valves to get around that?Definitely some sort of controls to the ducting, so it should be possible?
Gassing Station | Homes, Gardens and DIY | Top of Page | What's New | My Stuff