G and J

I guess this is like the difference between having aircon in a car and climate control. I’m thinking climate control for the house which would require control of both the MVHR and the ASHP from a single unit. But that sounds like (yet another) budget buster.

I’m seriously looking at a Zhender unit. I’m now thinking the ASHP and the MVHR need to be linked.

Ah, so the summer bypass kicks in automatically? Presumably you can set threshold settings? Summer bypass on = external temp is greater than y degrees AND internal temp is greater than external temp

Yep, agreed. So my earthwool type insulation will work just as well if it’s got a good airflow over it? The other attraction of a sealed roof was the exclusion of insects, messy things.

Getting a bit confuddled here. If your ASHP is in cooling mode do you somehow disable the summer bypass so that the air you’ve spent electricary cooling isn’t promptly ejected? I think the MVHR will cool the incoming air if the heat exchanger is engaged and the extract air is cooler than the intake air.

We are having a cold roof, and we are going for as airtight as I can manage. I’ve been boiling my brain about the roof space. I’m familiar with a fully ventilated roof, I’m sitting under one as I type, and I’m reading on here about ventilation ‘airwashing’ insulation and reducing its efficiency. As a result I started to wonder if a breathable ‘felt’ would remove the need for full loft ventilation. So I was dead chuffed when I found this post…. in this thread…. Before I get too carried away, is this allowed in Blighty nowadays?

So, to do the job properly would require industrial vent plant. Not going to happen. If it’s not worth the piddling extract airflow I’d achieve with an externally venting cooker hood then I might as well just muddle through with a recirculating cooker hood and save myself a cold utility room., relying in the MVHR air change to remove stinky smells. Simples.

Can tell difference.......was the larch sioox treated? If not would be interested to see how weathering differs from @Kelvin in a few months...........ideally we would not sioox but the nature of the plot (ie not open) means the north (1.5 m from neighbour/ south (1m gap) sides will not get the exposure of the west/east......minimal windows on north/south and cladding only on first floor/render beneath but.....

And can you hear them when they are running?

As someone who also bears the scars from looking in pans and forgetting cooker hoods….. Odd methinks that pretty much every kitchen design I’ve ever seen has open areas either side of the hob. Thinking of the shape of a basic fume cupboard wouldn’t we be better served with the hob boxed in? Got to be wide enough for handles but surely that would help.

Will be interested in what you find..........Russwood is about 11 hour drive so will go at some point but.......didn't realise we almost drove past the door on the way home from a scottish campervan trip in May Stunning......if we could have that profile would be a done deal!

Thanks for the pictures......looks great! For where we are now would be perfect, but new place is more urban........ Would be interested in seeing the thermopine........in the pictures Russwood have it looks good, but the worrier in me is concerned that the images show boards with fewer knots........

Oh. You mean I won’t be able to continue enjoying the aroma of curry night for several days after. I’m going off this MVHR malarkey….. 😉

When, as an adult, having moved away from the smokehouse that formed me, I helped decorate my parents living room - I started by washing the ceiling. I could not believe what was coming off. Perhaps that’s why I’m now a fresh air freak (who subconsciously likes brown).

Good plan. I like the gently warming background smell of smoke. As a child in the 60’s I was a three packet a day passive smoker so I guess it brings back fond memories. Well, memories anyway. Actually by Jove that’s it. I don’t want a passive house - I want a passive smoker house - everything needs to be various hues of brown. Our design is finally complete!

Hang on, I was asking a question, not stating what I know to be true. I think it would be great if the person who designed and/or signed off your design shared their view with you. Remember, finding an idiot like me on the net that just happens to have a convenient opinion doesn’t make that opinion true. And if the guys in those areas have put in a rule it will be fir a reason, i.e. some bad experiences, so that rule indicates to me that it’s highly likely that at some point in the past someone in the know believed that such cavities need active ventilation. What did said info source say about venting at the bottom?

You might be thinking of my baking skills. In a moment of inspiration I realised I should plumb my oven directly into the MVHR. 😕

I think the final answer will be to simply putting a big standard recirculating cooker hood in, together with a grease filter on the MVHR extract vent for that room. However I do like to work through the options to hopefully make good, informed decisions. The emotionals are difficult here for me. I’m a fresh air freak and currently live in a well insulated wind tunnel, so major purge type ideas resonate even if they are not really needed.

and then if I add a second fan and heat exchanger I will have invented the assisted airflow energy retention system. This time next year Rodders, we’ll be miwionaires…. Maybe not….. 😕

So I need: an in-line fan. two mains operated dampers, preferably return to closed if power is removed for simplicity. one of these vents to the alley above head height, ducted via the auto-damper (tm) to the collector above the hob via the inline fan. the other inlets at knee height in the alley and feeds ducts which outlet into the room at kickboard level maybe. Hmmm, still much opportunity for imbalance , but it mimics opening a window and that’s ok according to the PH guys. Just wear a big coat when cooking in winter….

We fry very little and still over time there is trace evidence of grease build up on our stainless steel cooker hood, so I take it as a given that there are nasties to be ejected/captured. We are not having a hob in our kitchen area as it is part of the big living area. Instead a hob will be used in our utility room, one wall of which is external and has a narrow and rarely used alley next to it, so perfect for dumping stinkies. So my thinking is maybe wall mounted fan ducted to collector above hob. But when this runs does it unbalance the MVHR? The direct air woodburner is in another room but will it blow back if one opens the door to load wood when the extractor is running? Do I need an auto opening inlet also in the utility room to balance things? Will the extra holes in my otherwise nicely air tight house undermine all my careful design/taping/etc? Yours truly, Worried of Suffolk.

Will this link work? https://www.ubakus.de/u-wert-rechner/ It takes a bit of getting used to but by looking at the build ups others have posted it falls into place fairly quickly.

So I’ll get over £4K back in used fivers from my MCS installer then. Cool. On a more serious note are those close to today prices? And which ASHP is that based on?

How far apart are your two properties, wall to wall? And what did they get you to do?

Understood. For us however the whole calculation is skewed by the grant which I’m expecting to substantially pay for our ASHP.