Nestor

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).

@MJNewton It has been functioning fine since February at 30% so I will balance the system best as possible and input the needed figures for the BC. Back to the cedar cladding....

@MJNewton P.S. Try and stick to one set of units; it gets really confusing swapping between the two! Will do. Found it all a bit confusing. Target is 80 L/s for each. At 100% boost I have : Extract 93.30 L/s Supply 76.65 L/s So it is possible with reducing the extract but might miss the 20 L/s for the sitting room. Its very close. I think the Vent Axia is near its limitations.

Yes the 80l/s is for the whole house. The 20 l/s for the sitting room seems unachievable even running at 100%. The Vent Axia Kinetic Plus has a maximum of 500m3/h. Do I add both the supply and extract m3/h flow rate as this would exceed the capability of the MVHR.

@worldwidewebs Hi there, can you offer any advice? I have the same Vent Axia from BPC in a similar size property. About 270sqm and need to achieve 80l/s flow rate for the size of house. Extract is achievable but even on 100% boost struggling to meet the supply targets especially in the sitting room (20l/s) Did you find a solution?

Might be some help.

@Conor We had 18 Kastrup windows supplied and fitted in 2018 and large Internorm slider. Kastrup Natur E++, 3G, outward opening, hinged on the side. Timber on the inside, UPVC then Alu on the external face. I think well made though had the glazing replaced on 12 windows due to visible roller marks. The hinge does not hold the window when open in a fixed position if a light wind. Simple adjustment screw on the hinge but not perfect. We had a price for Rationel from a local supplier but 30% more expensive, the Kastrup seemed a more substantial product.

@Donegalsd I can only advise from limited experience. It is simple to move the DIP switch SW2-4 to cooling mode and reduced the flow temperature to 12c. We only have wired thermostats in each room so had to manually change to call for heat, eg, if internal room temp was 26c the thermostat had to be changed to a minimum 27c for it to switch on the pump. It's a rather clumsy way of going about it. Does that make sense, others here will probably have a better explanation and method.

Do you just run the stop end bead past the PB across the edge of the door lining or run the PB with stop end across the door lining?

@Cpd

Is it the patio heater craze?

New self build, about 280sqm, Had 8.5 Ecodan supplied and fitted for £8514. Just filling out the RHI application. Payments over 7 years £6370. Will depend on your EPC. Many have self fitted similar system.

Hi Pete, Can you let us know how you get on with this product. Is a wearing course mean suitable as a final floor covering, foot traffic only. I might do a test and add some small stones to then grind back. Also do you know of an additive to change the colour of the product, maybe a grout?

@Nickfromwales Been running the UFH at 45c today, no loud noises. The final floor has not been laid yet and a crack has appeared in the screed. Also 3 loops provide the heat for that room and I notice the return pipe on one of the loops is not warm like the other 2. The floor area in part of that room is not warm. Flow gauges are all open as have auto balancing actuators on the return. I might remove the actuator and replace with a white return valve manual head and see if the water flows through that loop.

The flow temperature at the bar is 55c so I will adjust the blend valve down to 45c, Wunda mentioned thermal shock when introducing heat into the slab. Will observe the flow gauges, thanks.

I bled all 3 manifolds last week, it takes a while with 21 loops. I installed it all last year as has been working fine, no noise etc. All Wunda components and the instructions all helpful.