Nickfromwales

Expanded PolyStyrene Link

In a nutshell, fire / flames / smoke shouldn’t be able to escape the compartment (garage) into an adjacent one, nor in to the cavities. If there’s a plasterboard closing the cavity, sides and head, with a hardwood timber threshold, and the boards are plastered (or is FR PB) then that likely meets historic regs. Any windows should ideally be FR, especially if there are escape openings above on the same elevation, check your B Regs drawings to check re windows etc. Builder is right, so the door protects the cavity.

No chance!! You need a good few days for this to dry properly.

You may need to remove the plasterboard so you can see the whole valve, and then look again. The Allen head plugs usually give access to the NRV inserts, so you can change them.

Yes, that type are concealed but should have forward facing plugs which allow access to the NRV's etc, plus you should be able to remove the cartridge too. Get the dials off, slide the cover plate off, and take a pic. I'd bet its the shower, lets put a 4-pack on it

If you speak to them (CVC) they will assist with design etc and calculate flow rates and sense check it all for you before you place an order. TBH I just use my gut when sizing and numbering duct runs/type of duct/size etc, and I've been on the dot with all of the so far, as in when the systems have been commissioned downstream by CVC they have all passed with flying colours.

Air came out of the fresh, and left via the extract, so yes lol. It was an attic room, 3rd storey up in a PH, so a fresh alone wouldn't have done much up there tbh, so I altered the design to allow fresh in and stale out, and afaic it was doing the job nicely. No way to get ducts up the walls to the ceiling so went with these.

The oval is your friend here, unless you can add a 25x50mm batten and beef the wali thickness up? I've always bought from CVC Systems, who now shift boxes via Air-Haus.com, if you're looking to buy and self-install.

Is this somewhere you'll be staying long-term?

No, a totally different brand. LINK

I imagine it would be a balance with you checking flow rates vs results. Not sure if you can set the RH, but the manufacturers literature should make for good reading there?

You can use a lower profile rectangular duct, referred to as ‘oval’. I use it when we’re stuck for service space and because I always try to get the services absorbed into the fabric of each of my clients projects. I used it above, as we wanted the ceilings to be flat all the way to the wall. You can see the adaptors to convert round to oval, and the reason is that oval doesn’t give brilliant flow rates compared to round, so I try to minimise the amount of oval in a circuit. If you wanted to run a long distance, you can simply do two runs of oval which will perform better than one run of round, so there’s ways around any problem and folk pay me to find these solutions. 👍. Do try to avoid the floor ducts, and if you share pics of where you need to get to/from I’ll try to offer some suggestions for you.

Yup, you’ve got the wrong end of the stick here with what the Air Comfort does. Just use the enthalpy HEx? It’d be way more than £1k installed etc.

Nothing stopping both being in the ceilings? Going into the lower insulation layer over a B&B floor is feasible, as long as the duct is say over at least 25mm of insulation, and the duct is pre insulated. Just a lot of pain for not much gain, and I’d defo do everything in my power to avoid a vent in the floor tbh.

Lay off the bitumen, the fumes are getting to you.

https://www.ventilationland.co.uk/en_GB/p/ubbink-air-excellent-35sc-floor-grille-metal-white/9079/?gad_source=1&gad_campaignid=19924996771&gbraid=0AAAAAB0qKPDjHUZDh0lNdENfmtPQWtgAw&gclid=Cj0KCQjw953DBhCyARIsANhIZoahCChrTIG36mWPN1kSwPwP0sYxJBVdTQSq_cUyC602wwIIDmcRvbEaAqUqEALw_wcB and https://www.ventilationland.co.uk/en_GB/p/ubbink-air-excellent-35sc-grille-adapter/8481/ Can prob be found cheaper at Air-Haus https://air-haus.com/

I only fit Geberit tbh, just bloody bombproof stuff tbf, and I have never had a call-back.

Clients read up on these things, then ask how to implement / manipulate etc, and then I typically have to explain the pros cons and caveats and dissuade them ‘fiddling’ and just say to leave it alone to do its job. If a client knows it has a function, they want to fiddle with it.

Yup. The air comfort is an active heat exchanger, and requires a hydraulic connection to the ASHP for cooled or warmed water input.

Here’s one we installed in Oxford. The unit to the left is the Flair 400, and the air comfort is the unit to the right of it.

I've installed a few, and they do what they say on the tin. The only way to get heat energy through airflow is to boost the flow rate quite significantly, so if using this for cooling or heating (tempering) of the air, with a view to manipulating room temps, then the audibility is the trade-off. If you're happy to have an AC unit plugging away, then this won't bother you, and it's a less obtrusive solution; nothing other than AC will replace AC btw, but fan coils are the in-between solution. As far as introducing cold water evaporation, not so sure there, but are you better off with an Enthaply heat exchanger instead? A quick fix as I think you can just swap this out for the regular HEx. I'm not 100% sure, but I can ask. https://www.brinkclimatesystems.nl/solutions/accessories/enthalpyexchanger

Take a pic of the shower(s) and post it here before you fire up the chainsaw

+1, and it is a royal pain to have to try and explain this over and over again with each new client.

It all depends on the tap type, and whether or not the two bodies of water mix before being let out of the spout. So if you open the hot and cold tap at the kitchen sink, running the water slowly, the excess cold pressure that cannot force its way out of the spout contacts the hot water and pushes back, if the hot and cold are not balanced correctly. Mixer outlets usually come with a factory fitted non return valve, at least one in the hot, or instruction to fit some during installation if deemed necessary. Typical example is where mains cold is on the cold side and a gravity hot supply is on the other side of the same mixer tap. You say that you have cold mains permanently in the hot side, so It sounds like either the UVC install hasn't been done correctly, as in the cold feeds to all mixer taps haven't been taken from the control group (balancing valve) at the cylinder, so high pressure cold from the mains is one side, and balanced hot (at 3bar) is on the other, or there is defo a mix of the two bodies of water somewhere; (I suspect) a failed or failing non-return valve somewhere at one of the mixer outlets. So, when you turn off the isolating valve at the UVC control group, there is still cold mains in the property fed from the stopcock. When you open a hot tap, the cold mains is free to force its way into the hot pipework and then it travels backwards up it until cold water comes out of the hot tap you just opened. It is at this point I suggest you go into all rooms and listen to taps and shower etc to see if you can hear water "passing". Usually this is where there's a thermostatic cartridge, hence I say to check the showers first, just a PITA as isolating them is tricky. Most should be able to be disassembled in situ for servicing, but depends on make and model obvs. A lot of these come with factory-fitted integral non return valves, and if any crud gets into them then they cannot close fully, and then the issue presents itself after a period of time, a-la your symptoms.

And here is the exact pic(s)….more available…..