Nestor

Supply and extract on same external wall. 2.5m apart, extract 1.5m higher. Never had any cross contamination. Fine mesh supply clogged after 9 months.

Have the same unit fitted so much appreciated. Have bookmarked.

@Adsibob Never turned it off. Our MVHR runs 24/7, barely noticeable in the background unless on boost. You can set the supply, extract and boost speeds. Minimal condensation in the bathroom after having baths or long showers but clears quickly. Probably down to airtightness, quality of windows (3G) and overall build quality.

@Adsibob I used 40mm Pavatherm to cover all the walls and roof. Then 265mm and 275mm of Rockwool in 3 layers. Drawing enclosed. Floor, Wall, Roof Build up Jan 2018..pdf

I fitted Pavaflex above the rafters, a warm roof and would recommend as much as possible. As @Russell griffiths says, rafter size limitation as well as your maximum external heights.

@ProDave Well done so far. I hope to do same but with 285 sqm + 72 sqm garage.It just takes time, nearly 4 years so far! Does your cost include VAT?

Quick update as perhaps why the MVHR was not quite meeting the supply demand. I recently removed the external inlet grill and this what I found. Will retest the ventilation rates now.

No knowledge of Ubbink but I recently removed the inlet grill to fit cedar cladding and quite surprised at the amount of rubbish in the grill. This was after only 8 months. So access for cleaning quite important.

You have had help from others, I used the spaces, only 3 as I was fixing a 10mm x1000mm x 2000mm screen onto the wall and shower tray. I then siliconed once in place. If the screen is already fixed to the wall and not slipping down just fill with silicon.

Try here: https://www.wholesaleglasscompany.co.uk/acatalog/Transparent-Plastic-setting-and-Distance-Blocks.html

My only concern is where is the Pantry? Someone will be along to advise. HNY.

Sorry I meant just change the existing flow and return manifold first before spending money.

I would just swop over the manifolds as Peter and Nick have suggested. Isolate the two manifolds. You will have to top up the loops and purge the air, Wunda has all the details.

Same in the roof. Foundation is 100mm concrete, 150mm Celotex, 40mm screed. Figures below are for just over 10 months.

Yes that includes DHW. Stick built timber frame, From the outside : Cedar cladding, Counter batten, Batten, Breather Membrane, 40mm Pavatherm, 260mm Rockwool cross layered, VCL, OSB, Batten, Plasterboard, Skim.

Great topic @Oz07 All electric here in the new build, no gas or oil. We have MVHR, Solar PV with a PV diverter. A cat flap is the weak point in the fabric of the building. A bit difficult to be exact at the moment as our electricity usage is for 2 homes, 2 families with 9 people. The ASHP figure for the new build is approximately 4500kWh per annum. About 4500kWh for all other electric items. 9000 / 275 = 32.7 kWh.m2

Yes it does.

@BartW Similar build up to yours, but OSB on the inside. I have enclosed a hand drawing of the wall build up, from the outside its, Cedar Cladding Counter batten Batten Breather membrane Pavatherm 3 x Rockwool VCL OSB Batten PB @Oz07 Small birds mouth as I used 3.6m which just fitted. Floor, Wall, Roof Build up Jan 2018..pdf

I used 3 layers of Rockwool slabs, cross layered. 140mm,70mm and 50mm in the walls. Also 40mm Pavatherm on the outside of the studs. In the photo you can see the 70mm being fitted horizontally. The slabs are very manageable with zero waste.

Congratulations, that's such a big milestone. We still have lots to do here to complete but a pleasure to be in. Well done.

@LSB My folks who were in their early sixties at the time purchased an ancient Poclain 13T ( it was a brute and needed maintenance) to undertake many of the bigger tasks and a Yanmar 3T which Dad still uses today, he's nearly 80 now! Good times.

@Levo Standard G3 filters fitted both sides.

@LA3222 I used 5 x 50m rolls of 75mm radial ducting and wondering how much you have been specified?

@LA3222 Yes the High Flow has a maximum, FID, airflow 650m3/h. What is FID? It looks as though ours is under specified. I was wondering about how each room is assigned. Both our sitting rooms are of a similar size yet mine has been specified at twice the supply air. I think it is just to balance the figures. The MVHR sits very central in the house so has runs of up to 15 meters in either direction. It works well in the background at 30%, use the boost in the kitchen and the humidity sensors kick in when showering etc.

@Levo I did check the filters, gave them a good clean before testing. The Vent Axia we have has a maximum airflow of 500m3/h for a maximum house size of up to 260m2. The volume is nearer 750m3 due to high ceilings. Figures below were sent from the supplier last week. The initial supply air figures when purchased were 187m3/h! (2018).