gambo

1) Any good software I could use to calculate it? MRXBOXAB-ECO2B - probably slightly too small but I got it almost for free so want to test it first before going for something expensive. Also the house is leaking (old double glazed windows and no cavity insulation). 2) Do i need specific insulated mainfolds or just insulate it myself?

I'm finally getting closer to my diy retrofit but (again) stuck on ordering what I need. Assumptions: late 80s house, 4 people, 4 bedrooms, 3 toilets/bathrooms (once renovation completed), location in cold roof. 1) terminal vents are on the roof and the size of the pipe is adjustable. MVHR unit has spigots 125mm but it's a cheap unit and I may upgrade it in the future if needed. Shall I use 150/160 galv ducting from terminals to mvhr and reduce it at the unit? It will be 3-4m run with 2-3 90degree bends. 2) mainfolds - any particular difference between fancy looking ones like zehnder/ubbink and stainless steel from lidab/quiet-vent? 3) mainfolds - is there any reason why some of them say they are not compatible with comfotube? I'm doing pick-n-mix so am worried about something not working when I start installing it. 4) Noise Attenuation - where shall I install them and how many ideally? Only between unit and mainfold? I understand the need for one in supply but what is the benefit of having one on extract side?

That's a photo of bricks under window of the garage conversion

Just a random thought, could it be that there is no insulation in my concrete in either of rooms (late 80s house) but the reason it feels cold in the garage conversion is due to cold bridging from either the other garage or driveway?

That's what I was worried about. Lots of YTs and articles are from 5-10years ago, perhaps they tried to enter the market and it failed.

I'm in a similar boat and trying to decide how to insulate the ducting from the unit. Is there any best practice as to what to use? I can see different products ranging from flexible sleeves to some rigid insulation.

Why is VIP not practical? I have one quote for retrofit and it's £8k. So VIP would be just 1-2k and no mess. I may go for thin engineered wood or LVT but need to do the math on U values.

There is PB inside but I would be surprised if it was 2 layers or FR. So, is there any for-dummies description how such conversions should be done? I get that fire resistance is important so that's something I would rectify. What about floor? If it's just concrete on top of concrete shall I try to skim it and/or put VIP insulation +6mm cement board/plywood + engineered wood? What can LA say if I go for retrospective permission given it's 30yo?

Yes, thats how the wall of that room looks like inside the garage.

Apart from the cold floor, how can I fix this room? There will be a lot of mess done in that room so I don't mind redoing some of the work but have no idea what the actual issues are. Regarding the floor, what am I looking for when drilling?

We don't keep cars/motorcycles vehicles in the garage so fuel spills should not be a problem. The issue was flagged by surveyors but we accepted it. Question is what should we do now about it? Retrospective application for 30yo garage conversion?

I know it's not worth when comparing to energy savings but there are a few factors: We have to remove carpets and do something like engineered wood, I don't want to loose more than 10-20mm height, the cold feeling of the floor in colder days is really unpleasant. I've already have a small corner of the room don using 25mm PIR + engineered wood on top (nothing in between) and it already feels a bit claustrophobic.

No idea, we bought the house a few years ago. Neighbours say the conversion was done during the build but LA has no record of it. By the look of how it's done (eg.heating pipe running around sockets) it must have been done very unofficially.

Floor of the room converted from garage is level with the rest of the house. The difference between floor of the house (and that room) and garage floor (it used to be double garage so still one garage left) is around 200mm (+/-50mm). Hope that makes sense.

Mix up, I thought XPS was better but I've just checked that PIR has better parameters. I measured and the floor in the room is at least 150-200mm higher than garage floor and level with rest of the house.

The rest of the house is fine and I removed part of the carpet and underlay, and just for testing put 25mm PIR + engineered wood under my desk. I can see that 25mm already makes it much better. GIven it's garage conversion and potentially deep concrete, is there an option to remove 20-30mm of it just to ad XPS? Anyone knows of a company in SW to do such retrofit?

I've done some reading but still I'm not sure what to do. Late 80s house, 12sqm room (garage conversion from 90s). Based on how cold the floor is comparing to the rest of the house it's likely there is no insulation at all. Given the room is already a bit claustrophobic I don't want to loose more than 10mm of the rooms height (which is how it will likely go up when I replace carpet with engineered wood. The room itself can be insulated in a number of ways like IWI or EWI for the wall with garage and the temperature of the room is not an issue. The issue is just the cold feeling of the floor when sitting. What's the best way to approach it? Is it doable to remove 20-40mm of the concrete floor to make space for XPS? What sort of cost could it be to do it properly (full retrofit)? Even if I go for full retrofit I'm worried I'll end up doing it myself due to lack of trusted tradesman.

I think I'll go with tile vents, but now I'm not sure which ones are suitable. I can see ubbink UB19 but in the documentation it says it's suitable for " vent systems where an external pressure test is not required". What does it mean in relation to MVHR?

Due to number of issues with getting someone on the roof I'm thinking about running exhaust and intake through soffit. It will also let me clean in from outside through window. Main is issue is the space in soffit so I would want something up to 100mm wide, e.g. 160mm duct to 2x100m vents in soffits. Has anyone done it? Any recommendations for products to fit it nicely in soffit?

@richo106 I have couple questions as your installation seems similar to what I'm planning. Why so many ducts are so close the eaves? What vents do you have outside? Is there no issue with mould/condensation when outlet from the unit go upwards?

I'm in the same boat. Leaking house and the main reason for MVHR is to supply air to smaller rooms (bedrooms and study) when clsoed. Im planning it for a year but haven't had time yet. My main reason for MVHR is that trickle vents would bring too much noise from street.

What do you mean here? Outside air to mvhr or mvhr to room? I don't have space for 150mm in soffits but mvhr -> room can be whatever I want as everything will sit in the loft. It won't filter the air in the rooms as well as mvhr and there is lots of noise coming from the road which is another reason for not opening windows. Mrs also likes idea of having cleaner air and less dust on flowers.

A bit complex situation because house was renovated small couple years ago so want to limit the damage. I really want MVHR with some nice/good filters. The reason is I want cleaner air inside + kids close doors in their bedrooms which causes lots of bad air during nights in winter. House is a usual late 80s build with loft above and positioned in such a way that in order for summer bypass to work well I need to run external ducting through the roof or sofits. 1) Can I run inlet/outlet through sofits? I think I can fit 100mm but could I split the ducting into 2x 100mm to make the flow better? I want to avoid scaffolding for lifting roof tiles. 2) Does it make sense adding MVHR unit to a leaking house? I guess I can do some improvements around windows but am not planning anything massive. I don't need a huge efficiency, it's more about getting some fresh air well filtered + some recovery of the heat. 3) Can I install MVHR working only for upstairs? I would size the unit so that we can at some point extend it to downstairs too but initially we want to do it as simply as possible and DIY (got an offer for supply and installation of £12k for 110m2 house whereas supply only is around £3k). 4) Anything specific to look at when looking for a very quiet unit? I hate noises generated by fans when trying to fall asleep? Any good places where I could see units working?

I've looked at a few and looks like a good option but how do I prevent water coming on patio?

My (small) garden is quite uneven and lower close to the house and then goes up. Now I have a new patio slabs which replaced the old concrete ones and they are put in a way that they end up around 5-8cm below lawn level further from the house? What are my options to sort it out? Trying not to spend a fortune also don't want to remove it given I've already paid a lot for laying it.