Enginuk Posted February 5 Share Posted February 5 Hi there, renovation on going, and currently in 1st fix. Came across MVHR quite late, so won't be able to install the full MVHR now But I am thinking if I can go with a small DIY unit in the Util room to improve the air quality.. appreciate some advice. The downstairs Util room sits among kitchen, bathroom and study, so I am thinking to have a small unit in the util extracting the air from the kitchen, bathroom and util, and pushing the fresh air into the study room. Ducting will be pretty straight forward as these are all near by rooms. Question : as I have builder control overseeing the build work, this MVHR is 'out of scope'. If I were to go with this small unit / DIY, will this get refused by the building control and affect the sign off of the whole project ? Thanks Link to comment Share on other sites More sharing options...
Roundtuit Posted February 5 Share Posted February 5 Shouldn't be a problem, but if the house has been designed without mvhr, then I suspect you've got a combination of trickle vents on windows and extractor fans planned, and are not very air-tight. The benefit of heat recovery will therefore be minimal, so maybe just consider an extractor fan on a humidity sensor for the utility room/kitchen/bathroom? Link to comment Share on other sites More sharing options...
Enginuk Posted February 7 Author Share Posted February 7 On 05/02/2024 at 23:14, Roundtuit said: Shouldn't be a problem, but if the house has been designed without mvhr, then I suspect you've got a combination of trickle vents on windows and extractor fans planned, and are not very air-tight. The benefit of heat recovery will therefore be minimal, so maybe just consider an extractor fan on a humidity sensor for the utility room/kitchen/bathroom? yes trickle vent all over the place at the moment. I am just hoping to retain some of the heat from the dryer, cylinder tank, bathroom, kitchen in exchange for some fresh air.... Link to comment Share on other sites More sharing options...
Nickfromwales Posted February 7 Share Posted February 7 As the rooms will be leaking air in from outside, the MVHR would be a very bad idea IMO, and the likelihood (as the fan will need to run 24/7/365) is you will go backwards not forwards in terms of benefit. You may as well leave these bits of heat ebb into the heated envelope and go towards the space heating demand, and then deal with air quality in the study as you best see fit. When you calculate the very minimal heat recovery vs sucking in constant cold air from outdoors, I cannot see the numbers adding up. Spend the money on draft proofing and possibly filling cavities with insulation to improve the overall heat loss of the house, and that should be a far better bang for the bucks 1 Link to comment Share on other sites More sharing options...
Andehh Posted February 8 Share Posted February 8 I'm inclined to agree with Nick! Link to comment Share on other sites More sharing options...
JohnMo Posted February 8 Share Posted February 8 I think you have a few options 1. MEV, but get one with that varied speed base on humidity with humidity activated extract terminal, not much cost increase over a fixed speed unit. Add to this humidity activated trickle vents. 2. dMEV as above, but no duct. 3. MVHR - Almost what you described but do not supply to study, supply as far away as possible so the air washes through as much of the house as possible. Look how FreshR and similar units are used to get an idea. A through wall fan can get air movement, a dry room blows into a wet room for example. As @Nickfromwales says you have to be careful, a leaky house and MVHR even though it recovers heat it's is constantly moving air that may not need to move. You have natural ventilation AND you have forced ventilation on top of that plus running costs of 2 fans running 24/7/365. Link to comment Share on other sites More sharing options...
Enginuk Posted February 11 Author Share Posted February 11 Thank you for all your feedback, One of the reasons why I am exploring is that both myself and my wife suffer from hay fever from March to May. I heard MVHR has helped for some... It may be the filtering I will look at the recommendations Link to comment Share on other sites More sharing options...
gambo Posted March 10 Share Posted March 10 I'm in the same boat. Leaking house and the main reason for MVHR is to supply air to smaller rooms (bedrooms and study) when clsoed. Im planning it for a year but haven't had time yet. My main reason for MVHR is that trickle vents would bring too much noise from street. Link to comment Share on other sites More sharing options...
JohnMo Posted March 11 Share Posted March 11 9 hours ago, gambo said: My main reason for MVHR is that trickle vents would bring too much noise from street. Get accoustic ones https://www.titon.com/uk/products/window-door-hardware/window-vents-window-door-hardware/sf-xtra-sound-attenuator-vent/ But ideally also humidity activated ones. They are available https://brookvent.co.uk/acoustic-vents/ Also Duco and Aereco. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now