Dominic

p.s. although it is a Zehnder product it can be fitted with other MVHRs. I have a Nibe MVHR.

After the completion of my self-build passivhaus project, I have a Zehnder Comfopost CW8 water to air heat exchanger that I no longer need. This was intended for installation on the MVHR system as an extra option for warming/cooling the air in the MVHR. That was in my original design for the house which had no UFH or other heating/cooling source upstairs. But instead I have now installed UFH upstairs which means this space can be heated/cooled through the UFH. As a result the Comfopost is now surplus to requirements and I plan to sell it on ebay. Before I do, though, I wondered if any self builders or others on here would like it for their own project. If so just message me and we can discuss. The unit is in pristine condition.

UPDATE: On 24 June I received a letter from HMRC giving me formal acknowledgment of receipt of the claim (four months after it was submitted!!) and saying it should be processed within the next six weeks.

Has anyone got an idea what the current HMRC processing times are for VAT reclaims? Mine went to them mid Feb. I heard nothing for three months so decided to ring them. Good news is I got through quite quickly. Second good news is that they confirmed they had the claim safe and sound and gave me a reference number for the claim. Bad news is that they say they have got more claims than they had planned on, are short-staffed and could give me no idea when my claim would reach the top of the pile. Has anyone recently been reimbursed? How long did it take? Were there any complications?

PI - I am about to purchase exactly the same configuration. Did you go for plastic or brass? Any thoughts on plastic vs brass?

Thanks Terry. All good points and I am reasonably comfortable I have this covered. No racking in my case. I will be crawling over the ventilation/weatherproofing with my roofer and builder and the BCO but, in general, with a warm roof, the counter battening and the clay pantile system, the tiles are sufficiently 'air open' to allow the transmission of water vapour from the batten cavity through the tiling without great need for extra ventilation. But I am not necessarily relying on that and I had planned on ventilation at the eaves and ridge with the exact configuration of this subject to the above BCO discussion. For the eaves, there will be a slight overhang of the tiles beyond the brickwork to the gutter. The brick will be corbelled at the eaves with the necessary eaves protection system/comb/vent sitting on top of the corbelled brickwork. Out of interest, I was trying to look through your old posts and your blog to see if your MBC roof was pumped cellulose and vaulted insulated roof (which is the case with mine) or whether the thermal envelope in your build is lower down below a cold roof void? Going back to my original question about starting the lowest course of clay roof tiles in the absence of the brick skin, my current plan is to extend the counterbattens 250m or 300mm out from the TF and support them with a temporary propped boards underneath to take the weight of the bottom row of tiles plus temporary guttering (it is a chalet bungalow design so the eaves are only 2.4m or so high, enabling us to prop them easily from the ground). This will be removed gradually when the brick work gets up to eaves level and the bottom course of tiles can then be lifted and refitted allowing the final eaves system to be put in place between the corbelled brickwork and the tiles.

Many thanks HerbJ. I didn't see your very helpful post when I posted mine this afternoon so please don't think I was ignoring it. Useful to see your pics as well. In my case, I am planning not to have a fascia board as, with a chalet bungalow design, the overhang would bring the roofline just a little too low down so I don't have the option of forming the joinery for the fascia board/guttering. But your post is useful. I'm getting there. It might be that I could fix a temporary fascia and guttering in place. Views/ideas of others welcome.

Thanks Terry. Much appreciated. In the meantime, I have hit on the obvious solution of extending the counterbattens down the roof so they extend beyond the TF and the line of the eventual brickwork. This should permit my roofer to fix the bottom course of tiles in place and support them with a temporary dummy lat. We should also be able to rig up some temporary guttering/downpipes pending the construction of the brickwork. The image below shows the solution.

A brick skin will be added to the construction with a 50mm cavity between the brick skin and the TF. Obviously most of the pantiles "sit" on the TF roof (or, rather, the battens) but the lowest course of tiles need to form a junction with and slightly overhang the bricks. No fascia board, gutter rise and fall brackets in brickwork.

I would welcome advice on this. I have an MBC TF being erected later this month. Once the frame is up I am getting the roof (clay pantiles), in-roof solar and roof windows on immediately afterwards followed by windows and doors. But with the brick skin obviously taking a while longer, how did you (a) solve the problem of how to manage the lowest course of the roof which has to sit on the bricks (in my case) and (b) similarly, in the absence of the external skin, how did you rig up guttering?

Faz - did you just devise the PO yourself or is there a model wording somewhere?