Happy to. One day (when/if I finish it!) I'll do a proper write-up as I think some aspects of my system could be of interest to other retro-fitters that don't the have the luxury of open ceilings, webbed joists etc of a new build (okay, we don't the stresses either! )
As brief background, my system was born out of the desire not to spend loads of money and effort on insulting our new open-plan extension only to have (at extra cost) trickle vents added to the already-expensive lift-and-slide doors. As with many of my ideas and musings next thing I'm doing is looking to ventilate the whole house with MVHR...
I could see strengths and weaknesses with different components from different manufacturers/suppliers and so, taking advantage of the cross-compatibility of the 75/63mm radial duct systems hand-picked different parts for different reasons:
- MVHR Unit - Titon HRV 1.25 Q Plus Eco - Had all the features I desired (e.g. right size, summer bypass, generic filter baskets etc) but most importantly was available cheap (£350 I think?) from a seller on eBay who was involved in ripping out hundreds(?) of them from a development to replace them with the next size up as per the contracted spec. They'd only been commissioned and the properties yet to be handed over to residents. I visited the guy at his house to collect it and am convinced by this back story. Came fully boxed with all the extras (from the new units), and seem good quality with ebm-papst EC fans and Recair heat exchangers. Happy to pass on the contact details to him if others are interested as I think he's still got some left.
- Control System - My brother keeps reminding me that he never touches his MVHR unit (other than filter changes) however the engineer in me still wants to monitor/control it. Rather than spend hundreds on the proprietary Titon control units I will eventually be building a Pi-based controller to monitor/graph performance and operating states, as well as to provide more configurable automatic controls (holiday mode, humidity-based switching, summer bypass/purging, PWM motor control etc). In the meantime I will leave the unit to do its stuff but I am fitting momentary boost switches in place of the existing extractor fan isolators just to give some manual control should it be required (and also in case we ever move on - I don't think the new owners will appreciate being left a hand-written user guide and downlink link to my bespoke Android app!).
- Ducting - Airflow Airflex Pro - Whilst all 75/63mm ducting is seemingly interchangeable that is not to say they are all made the same. I've handled some that has been far less flexible than the Airflex Pro stuff and so went for this as I knew it was really good quality.
- Distribution Manifolds - Blauberg 8-Port - I was going to make my own out of ply but at only £35 each I couldn't resist. They were easy to line with acoustic foam and I will be combining them with their own ducting adapters and (expensive - might DIY) restrictors to adjust the flow at this end rather then the ceiling terminals (reduces room noise and avoids unauthorised fiddling!).
- Silencer - Blauberg 600mm - Again, another cheap offering from Blauberg at less than £30. Opted just to fit one on the supply side, but have designed the extract pipework to allow an easy swap-in if need be.
- Ceiling Terminals - HB+ Conus Airvalve - Chosen after I saw @JSHarris's setup and liked them both for their aesthetics (slightly less 'office toilet' than some as my wife put it!) but also that they are designed to work with manifold-mounted restrictors (i.e. they can't be screwed in/out). I bought them from a supplier in the Netherlands as even with shipping there was still quite a saving over UK suppliers.
- Terminal Adapters - Domus - I went for these for those locations that I could easily access (kitchen, lounge, dining room due to ceilings being down; top bedroom, en suite and dressing room due to loft access) as they were a bit cheaper than some others, are nice and compact etc. Not much to choose between really, although some seem very expensive for what they are. For other locations where I only had through-the-ceiling access I've gone for a bit of a Heath Robinson lash up that I could install through a 125mm hole from below consisting of a 125mm 90 degree elbow combined with a 125mm to 75mm reducer.
I think that's pretty much it, aside from all the ancillaries, fixed piping etc. In total I think I've spent £1200 in total which I don't think is too bad for a 100m 11-port (12 duct) system. Yes, more than the trickle vents in the doors that kicked this adventure off but hopefully of more functional value.
Edit: Apologies to @j_s; I wansn't intending to deviate the thread with all this!