phatboy

Hi, by top I meant top-sides - I'll definitely be using the side vents to avoid an extra 90degree bend. I think ill use rigid from the unit, and a short length of flexi where the pipe goes horizontal. Just need a nice cool day to go in the loft and get on with it!

Thanks @joe90, I probably should mount it from the roof timbers really, but as the wiring is from below just float it 1" above the floor. Your unit looks to be horizontal, where as mine is vertical. I think I also have an idea now for supporting the pipes, and will move the flexible section to where the vertical from the unit, meets the almost-horizontal to outside and to manifolds. Cheers

Hi all, I am ready finally to install my MHRV unit - all of the plenums, 75mm pipe and manifolds are in, and loft covered with 200mm of top-up insulation and a new deck above. I have a hipped roof, and so don't have a wall on which to mount the unit in the loft. I am struggling with how I will get the pipes to the top of the unit, and supported due to the need for a flexible section of pipe on the in/outlets. It's a Vent Axia Sentinel Kinetic BH. Any advice or pictures of installs much appreciated! Tim

Thanks @lizzie, my extractor also has a easily detachable grease filter that I should and will clean more often now we are re-circulating. My MHRV extract is about 1.5m away, so that's good. Hadn't considered a grease filter in there, but will see if BPC can supply something now. Thanks!

I am about the convert my extractor to recirculating mode as MHRV is going in. It strikes me as odd, and not very good, that after passing the grease filter and carbon filters, the air will just disperse into the metal chimney and out through the vents at the top. Is this satisfactory? I don't think the filters will capture everything, so best case is the inside of the chimney will be greasy when I next remove it, or worse the tiny gap at the top of the chimney (As it's only fixed on the back corners) will leave a grease stain visible on the ceiling. Or am I way over thinking this, and it will be fine? I've only ever dealt with ducted extraction before. It's a Caple CGC610 Many thanks! Tim

I could have got away with that if I'd considered MHRV at the refurbishment stage, but I am 2 - 3 years on now and would end up dead if the wife caught me with a length of trunking in her kitchen We are fairly disciplined with using the cooker hood fortunately.

Thanks Nick, that looks positive! The variable input voltage will do the trick. I'll probably not bother with a railed enclosure, just put it in a plastic box with a screw on lid, as once its set i should never need to touch it again. Many thanks Tim

@Nickfromwales I need to boost when the extractor is turned on to help purge the cooking smells and moisture. From what I can tell, the various inputs on my unit are not momentary, and rely on an input for the duration of the boost. Momentary would also not be great, as it could turn off boost whilst cooking was still happening. An over-run built in though would be good, so it boosts for x minutes after the trigger has gone.....

This is looking unlikely to work, ParcelForce is about the only cost effective option, but it says its too big for all services! Craziness and I'm sure I've received similar sizes before..... I'll persevere, but don't waste any time at this stage please packaging anything, in case I cannot get anything sorted. Many thanks Tim

Hi, I'd appreciate any feedback from anyone who has experience of this, before I floor the loft and make cable runs a whole lot more difficult! Thanks Tim

Something like this: https://www.ledhut.co.uk/spot-lights/ceiling-lights/18-watt-led-slim-downlight-100lm-w-tpb-4000k.html Fire rating is only usually needed when there is a separate unit above, I think. So basically in flats, not in houses (I think)

Hi all, I will soon be installing my Vent Axia Kinetic BH unit up. It has multiple volt-free connections. I have a PIR that I have set to volt-free mode for the bathroom, but unsure of the best approach for the kitchen extractor to set the system to boost. There is a LS input on the unit, but this expects a 240v input. If the cooker fan is set to anything but full power, I'd expect the voltage to be lower and so not activate this circuit. Alternatively, I may need to rig up some sort of relay from the supply to the hood extractor fan, that feeds to a set of the volt-free terminals. but I don't think these connections have an over-run facility. Interested in how other people have dealt with this. Cheers Tim

Hummmm, yes postage may be an issue! Pallet charges to Jersey are huge, around £100. I'll do some research and see if I can find a better deal for a basically 5kg pallet! Which part of the country are you in, as we do get some people who advertise they are taking a van to a particular place and sell space on the return. Cheers Tim

So sorry to hear that. Don't worry yourself about this, we can pick it up again in a few days Cheers Tim

@ProDave, I was thinking to use those in one of the bedrooms to direct air away from the bed, I've read about people experiencing 'cold shoulders'. Equally I will use them if it seems a vent is too close to the wall.

Thanks @JSHarris. I have calculated it just now, but based on the regulations in the Jersey Building Control 'Ventilation Rates for Dwellings'. Based upon it being a 3 bedroom property, I would require a rate of 21l/s. However, the whole house rate based on 0.3l/s per m2 comes out at 28.2l/s, so extremely close to the 29l/s quoted by BPC, based on a kitchen, bathroom and utility room. I never intended to actually run the system at those rates based on what others here have said and experienced. Interestingly, I cannot find anywhere that says I must notify about this work - probably because our rules tend to lag behind the UK a bit! There are rates that must be acheived in ventillation, but no need to notify when making changes of that type, or so it would seem. Tim!

Thank you very much @JSHarris, very useful and helpful information I am using the 'mushroom' type I'll consider going a little closer than 50cm in some cases then, to try and balance aesthetics vs function. I wish I'd discovered this forum sooner! Whilst I have you, may I pose another question? My design from BPC has 5 inlet valves, (living room, bedrooms, dining room, and 3 extracts (Kitchen, bathroom and Utiltiy). The utility has the required 8l/s, however the room is tiny, approx 3.25m3. Also, this extract has just 1 75mm pipe fitted, maybe as it's almost next to the manifold. - If I was to keep to the 8l/s, should I double up the 75mm pipes to this valve? - I'd prefer to drop the rate so that I can reduce the door undercut to stop washing machine noise. Is this a reasonable thing to do? The room contains a washing machine and condenser dryer only (due to it's size). Sorry if that is worded confusingly, I'd be happy to share my design if you (or someobody else knowledgeable) had time to glance over it? I see BPC get strong reviews here, however I have found the information to be a bit lacking sometimes, despite the kit being excellent. Thanks Tim

Hi all, Sorry for the basic question, but the answer seems to be missing from the BPC guides and I've only found a few fragments of information online. How close can a plenum be to the corner of a room to work properly. I've read 50cm somewhere. Can I be a bit closer if needs be (Ceiling downlights are all roughly 70cm from the corners so I need to work around them as they got there first!) ? For kitchen and bathroom I am going to be fitting them roughly centrally, according to BPC's design. Hopefully once my install is done I can provide advice too Many thanks Tim

Perfect, thanks! Yes 3m would be enough, as that will get me from the plenum, along the flat roof area, and into the main loft where I will convert back to 75mm round. Cheers Tim

I remain hopeful

Thanks @JSHarris, I hadn't thought of that but it makes sense - the illusion of shade! Either the inlet or outlet will be 1ft above a corrugated garage roof - I think I'll make that the exhaust , and it's closer to the South-West corner. Tim

Hi all, In my MHRV design, I have the supply and extract from the house through the soffits on the south of the building. I appreciate this will cause warmer air to be drawn in, especially during the summer, but will it cause a major issue? There is no shading on that side so it will sit in direct sun for a lot of the day. I hadn't thought of this as an issue until I started reading here, then it got me wondering Thanks Tim

Hi all, I've just joined the forum having purchased everything for a MHRV system. I'll be posting more in the next few days and weeks no doubt as the installation begins! BPC have done my design and supplied the pipework etc., and I have sourced the MHRV unit elsewhere (Vent Axia Kinetic BH). Only issue is, I have a insulated flat roof in 1 room and I am not going to be able to get the 75mm round pipe, with insulation, through (Need insulation as it will need to run on the cold side). Wondering what the chances are of any members having a 3 - 4m offcut of 51mm x 114mm oval left after their install, that I could buy? I certainly don't want to buy a 20m roll as it will be mostly wasted and seems to cost a fortune. I'll then source an oval entry plenum. Any help MUCH appreciated :) Tim