Feedback on diy MVHR after 3months.

Hi all,

Just thought I would give a bit of feedback on our MVHR. In short its the best thing we could have done and the results have been entirely positive.

The MVHR was part of a general renovation of a 2000 era semi at around 105m2. Cost of materials were around €3K. We insulated all external walls with 100mm insulated plasterboard, all seams taped for airtightness. We also installed triple glazing throughout so the house is relatively airtight at this stage. I installed the MVHR myself using a Vent-Axia sentinel unit fitted into a high level kitchen unit. We have extract points in the Kitchen, bathroom and on-suite. We have delivery points in the living room and the three bedrooms. The system has not yet been balanced so is probably not working at its optimum level.

The house will lose 1C of indoor temp per 12hours for a difference of 10 degrees to the outside, and 2C for a difference of 20C to the outside. If we are in the house and using applicances this rate of loss drops considerably. We have no condensation issues and the bathroom clears of steam with 5mins of having a shower. Washing hung on a rack in the kitchen drys in less than 12hours generally. The air is fresh and dry at all times and we sleep considerably better than we did without the MVHR unit. The whole of the downstairs is open plan apart from the hallway.

The unit produces a noticeable level of hum in the kitchen, but far less than any other extractor fan i have ever used. Its barely noticable after awhile. There is a barely noticeable hum in the bedroom from the room vent. Noise travels quite easily from room to room through the ductwork. If a neighbour throws on coal to their open fire then we do get a smell of coal smoke around the house - this is the worst downside sofar but I am not certain that any ventilation system would do differently in this regard.

So again - huge success and my wife who could barely understand the reason for going to the considerable expense and trouble of installing it is now an absolute fan.

mr.stonewall

My wife loves it and we have a ceiling airer in the utility, couple this with underfloor and the underfloor manifold in the utility, it's super fast to dry. Did it DIY myself approx 11 years ago during a self build.

Building air quality is lovely and fresh

AmpMan

I've been meaning to do this myself.

Do you still vent the cooker extractor out as normal ?

https://www.boards.ie/discussion/comment/121743842#Comment_121743842

The cooker extractor in ours is vented internally because the new air vents are using the wall space that the old extractor used. We are going to add carbon filters to address smell issues.

However an externally vented extractor will represent an unbalancing of the MVHR system and a considerable loss of heat to the house. As such a recirculating extractor fan is the correct approach.

mr.stonewall

https://www.boards.ie/discussion/comment/121743842#Comment_121743842

Charcoal filter and vented inside. Just hit boost on the panel if someone( me ) makes a cock up cooking

TimHorton

https://www.boards.ie/discussion/2058335218/feedback-on-diy-mvhr-after-3months

Where did you buy the equipment?

Calahonda52

Good job!

So can we have some intel on the materials used pls

D or semi d gaff?

type of ducting

type of manifolds

type of silencers.

location of intake/exhaust

normal run rate as % of max

Any pictures?

Calahonda52

https://www.boards.ie/discussion/comment/121744110#Comment_121744110

are the agents here, have always found them good to work with

I am currently setting up new internet so will post later.

We got our supplies from this crowd;

https://www.ventilationsupplies.ie/

There website is a bit patchy as a lot of the items are not listed. I found them helpful with the design but the delivery was a bit chaotic as they missed items from the order and these had to be sent on separately. Overall a good supplier with the Vent-axia Sentinel the best price in Ireland.

We used PIA 125mm ducting and lengths of flexible insulated ducting to go from the vent axia unit to the outside and then to get into the loft. All distribution points from there were using the corrugated flexible 75mm - two pipes to each plenum.

More details to follow.