dpmiller

Yup. Spent too long fitting extra relays to Microflows to signal fan on, back in the day. And that was when they had the Mk1 auto speed control which used a resistor/thermistor pair for feedback & isolation. SLOOOWWW response...

I hope you have more success on the BMS side than some of the lab suites I've been in. Inputs vs feedback vs actual stable control is one heck of a black art...

built-in humidity sensor in our Vent Axia works remarkably well

We did things completely differently. We trawled online "book plan" services (there are at least three big ones over here), found a design that was attractive to us and then via phone and email discussed changes to the design to suit our needs. Ended up being a full redraw, and our guy was absolutely superb.

so you don't have any data?

how do you know that 2ft diameter is overkill but yet 1.5ft is "too slim"?

Is it OK to use EPS rather than PIR to insulate the reveal?

Weird. my 2-storey, 270sqm build only uses 140mm frames. will my house fall down?

standard black stuff. Concentric in our case.

our DNO (NIE) mandates a red hockeystick, and most of the cabling on rural sites is direct buried.

what about going top hung then, don't they generally have the usual top bar to vent and rotate as well as a lever handle at the bottom for top-hinged function.

https://www.keyliteroofwindows.com/shop/centre-pivot-04-780x980mm/

well at some point, this will then likely need input from a structural engineer surely?

is the TF being stickbuilt on site or is there a spec to go to a factory?

they do white wood too.

non-woven mat (as used in spray booths as paint catcher, and prefilters in fumecupboards etc, costs next-to-nothing and can even be washed if you're gentle. Basically the same stuff used in the MVHR units anyway...

Personally I wouldn't panic about a vent being present... have a look at the Keylite products too. We went for their UPVC units and they're very impressive, much handier to install than a Velux.

it's my perception that a perfectly-smooth tile is grippier when wet than the dimpled non-slip things used round municipal swimming pools.

is PTV carried out wet or dry, and what material is used as the slipper?

will it run off battery also?

We're drawn at 16@176r x 250g, 900wide with a 180deg turn halfway. Current temp stair is a single run slightly steeper and no hassle at all so I suspect the 176/250 will be pretty comfy.

smoke stick / joss stick would do it

16kW is pretty big for an efficent new build.

might get away with nothing more than bringing the cistern duct into the main one with an elbow facing downstream.

not powered by, Ian. Create a low pressure zone in the main extract duct to draw flow from the duct coming from the cistern.