Alan Ambrose

Ah, maybe we should chat about the next meeting for the last 5 mins of the previous one. Does next Thurs work @G and J?

@Gary Martin - can I ask - was there are residue or other weirdness after the Aero Barrier guys left? What stage did you call them in? After painting maybe?

Next Thurs maybe?

>>> buy the best That's what I thought too until I actually got them in my hands. Another negative : the roof is black, the panels are black and the rails are .... yeah, silver. Probably cheaper for Renusol to silver anodise rather than black.

The one on the top is the apparently kosher Renusol rail & clamps, with the slightly dodgy pressed steel clamps. 24mm clamp width. The one below is an eBay seller 'Renusol' rail & clamps with proper T-nuts. Much better design IMHO. 18mm clamp width but shorter rails.

@Mike - I was meaning here (below) and yes, the MVHR calcs say a 180mm diameter vent (i.e. 25,000 mm^2) gives 2.3 m/s on boost and the UB19 is 22,000 mm^2 - so 'close enough for government work'. @Kelvin - that's clever, but we don't have any waste running from the garage, and it's also some distance away.

To avoid collision with my PV panels and Velux windows, is there any reason why I shouldn't put my MVHR external vents under the gable soffits using terminals like these? Ventilation Tile UB19 Slates 500mm x 250mm (NJ) Anthracite | Ubbink Also, can I use these, this time on the top of the roof, for SVP vents rather than 110mm pipe? For various reasons, mainly aesthetics, but again I want to avoiding shading my PV panels.

Yes, as a sense check, 200W of LEDs is equivalent to to 40 x 5W LED bulbs - that’s an enormous amount of light. And, even then 200W @ 24V is 8A of current. 1mm^2 cable should handle that very easily.

The subtle thing about higher voltages and LEDs in series is that one failure with bring the whole string / light down - so you’re looking at a shorter lifetime.

That’s quick - what kind of appeal, and was that 7 months from file-to-result or from ‘start date’ to result. My gap from file to ‘start-date’ was 4 or 5 months from memory.

Ah yes, I ordered a set in - the mid-clamp is indeed 24mm. I'm not that impressed - the clamps don't slide along the rail easily. I guess they will using a rubber hammer or some such. Seems a pity as the aluminium rail itself is good. Anyone have suggestions re better fixing PV systems for trapezoidal roofs?

I’m using PHPP to calc Uw so I just needed the glazing number. Point taken though - the glazing may make inconsequential difference to whole house numbers.

@JohnMo - this kind of thing for multi room? https://www.abilityprojects.com/fan-coil-units?gad_source=1&gad_campaignid=22492647782&gbraid=0AAAAA_dPIDvt0GTJyd8qM3Coah64cNGF4&gclid=EAIaIQobChMIuYasioPPkAMVepNQBh1NuhvrEAAYAiAAEgJza_D_BwE How does the ducting compare to MVHR? Much bigger?

Next Thursday maybe? I think IP14-ish is vaguely the middle of our little group? The Bull at Bacton or Debenham Lion?

Be careful re planning amendments and CIL. But congrats on getting the permission - and there’s wealth of info here on just about any self build subject. A picture of the current building maybe?

LEDs are current-driven devices (they’re diodes, of course, so ohm’s law doesn’t apply) - so as long as you have enough voltage greater than the forward voltage of the LED (string?), the voltage drop should be irrelevant.

100m sounds more like a microwave link rather than wifi - I can’t imagine you would get the bandwidth you want with wifi. Maybe I’m wrong: https://www.broadbandbuyer.com/products/47399-ubiquiti-lbe-5ac-gen2-ptp-pnp/specifications/#content

Similar, but I would maybe put in the NMA anyway to avoid the hassle of arguing with enforcement. The LPA know what’s going to happen if they refuse it. And congrats for standing your ground with them and winning.

You may need some SUDS calcs. But I would poke around on your LPA’s portal and find a couple of applications with a similar condition and see how they discharged it. That’s a quick way to see what’s needed.

My better 1/2 resolved a problem with Wren recently. The quartz worktop suppliers nominated by Wren came up with a stupid layout with a cut right in the middle of one of the main surfaces - halfway between the hob and the sink FFS. Both the quartz guys and Wren argued vehemently that their solution was the only one that was possible. So she found a couple of other quartz companies that did an obviously sensible layout and she ordered from one of them. Only at that point, after she had proved that a cut in the middle of the worktop was unnecessary did Wren relent and credited her with the fees they had taken for the worktop. It probably helped that she was trained as a lawyer. Not their finest hour.

FYI I just found the g & U-value for Velux's various glazing options. It took me quite a while so I thought I would record it here: In short, the common triple-glazing option '66' is 0.6/.44, Slightly, better options are '62' & '67' at 0.5 and average g-values. '70' is the standard double glazed at U-value of 1.0. The 'heat protection' option '69' is an oddball with g-value (transmittance) of .27 but a not so great U-value of 0.7. This is from: Velux_GGU_Technical_Data_Sheet.pdf

Anyone have any thoughts / tips re extract & supply valve positions - particularly in a vaulted ceiling room? Is there an advantage / disadvantage in having the valves high up in the ceiling?

>>> but it only resulted in a 0.1Uw decrease so probably isn’t worth the extra cost That's a very good point. I just did some quick variations in PHPP substituting different Velux glazing: '66' triple glazed over '70' double glazed gave a 1.5% reduction in annual heating requirement and a 0.4% reduction in solar gain (worth about £25 a year) ... but at a 44% (£724) capital cost increment.

FYI ArtisanElectrics have a video where they put PV on the curved metal roof of their new office. Probably trapezoidal rather than standing seam.

@Smallholdertoo I would be interested to hear how you got on with this - I'm looking for a similar thing.