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Alan Clarke

Alan Clarke

@alanclarke.bsky.social

1.7K followers 310 following 590 posts

Energy & buildings engineer, Passivhaus, mountain biker, veg gardener/rewilder

Political science 27%

Sociology 24%

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Alan Clarke @alanclarke.bsky.social · 2h

Easiest ventilation to fit is continuous extract - can be single fan per wet room - or ducted to one fan.

This will ensure sufficient ventilation however airtight the house is. There's sonetimes an assumption this is just for medium tight houses but is good for any feasible level of retrofit seaing

Reposted by Alan Clarke

Graeme Swanson @swansonian.bsky.social · 3h

It took us too long to realise when Musk called that cave rescuer a "pedo guy" he meant it as a compliment.

Alan Clarke @alanclarke.bsky.social · 1d

Subtle age bracket there - you cant be old enough to have watched jim'll fix it or rolf harris every week, but old enough to know about their offenses and that they had been on telly

Alan Clarke @alanclarke.bsky.social · 2d

That's outside - an indoor methane leak flattens a whole house from time to time - what would a hydrogen leak do inside a house?

Reposted by Alan Clarke

Octopus Energy @octopus.energy · 2d

This is the short edit.
Find the full stress test on our YouTube 👉 www.youtube.com/watch?v=asiY...

We blew up a kitchen. For science. 💥 Hydrogen vs Methane Gas Leak Test

YouTube video by Octopus Energy

www.youtube.com

Reposted by Alan Clarke

Trystan Lea @trystanlea.bsky.social · 3d

On your question on required flow temperatures. That's an interesting one. It seems that there are a very large number of properties in the UK with sufficient existing radiators to run at flow temperatures of between 45-50C without radiator upgrades. This is what enables HeatGeek's ZeroDisrupt model

Alan Clarke @alanclarke.bsky.social · 3d

Just been in edinburgh today where I noticed that pavements had been gritted - wondering if this is norm in scottish cities?

Alan Clarke @alanclarke.bsky.social · 3d

Is that a new change? I recently emailed John Lewis, despite warnings they would take days to answer an old fashioned email, and in a few hours had real human sorting out return of faulty product

Alan Clarke @alanclarke.bsky.social · 5d

My mum was ready to give up driving due to frightening habit of cars and cyclists suddenly appearing in front of her, but still when her new optician said her cateracts were bad enough to merit operation asap she said she assumed not bad enough to stop driving. The optician put her right on that!

Alan Clarke @alanclarke.bsky.social · 8d

And being new homes they will have EV charging capability which is another way to bank PV surplus

Reposted by Alan Clarke

Alan Clarke @alanclarke.bsky.social · 9d

That was from Dai, Solarkinetics about same as i recall

Alan Clarke @alanclarke.bsky.social · 9d

We have ASHP and EV, and on Octupus agile paid 17p/kWh avg in 2025.

Exc. EV that was 4800 kWh so at say 7p/kWh saving (after conversion loss) there's max £340/year saving but would need your 26 kWh to meet winter demand...prob better with smaller but sums aren't straightforward and savings not huge

Alan Clarke @alanclarke.bsky.social · 9d

On newbuild the saving on PV looks fine, and not installing at time of construction effectively costs £1000s in additional retrofit costs like scaffolding.
However batteries can be added relatively easily at ground level later on should the economics improve

Alan Clarke @alanclarke.bsky.social · 9d

I had a quote couple of years ago for 12 panels and 5kWh battery at £13K - seemed like the going rate at the time, battery was costing about £4K of that

Alan Clarke @alanclarke.bsky.social · 9d

Thanks for pointing that out - I was surprised to see batteries in there - hadn't seen reference in latest welsh part L consultation

Alan Clarke @alanclarke.bsky.social · 9d

Where do you get 15% return though?
£180/£5000 is only 3.6% which is less than my building society account, and the battery/inverter has finite life as well

Alan Clarke @alanclarke.bsky.social · 9d

www.theguardian.com/environment/...

Can anyone here sell me the battery bit? MCS work refed showed £600/a saving for PV and £180 for battery - is that worth maybe £5K to install?

Is there a UK merit in batteries in houses vs on grid or at solar farms?

And wont my next EV be grid linkable anyway?

Ministers may cut green tech mandate from new homes regulations in England

Critics say removing battery installation requirement will reduce amount homebuyers save on energy bills

www.theguardian.com

Alan Clarke @alanclarke.bsky.social · 11d

The standard filters are for particulates and probably wont deal with smells.
Could add activated carbon filter to intake but decent capacity/lifespan is large I think (there are some carbon ones that fit standard mvhr filter slots but i'm not sure if they are that good)

Alan Clarke @alanclarke.bsky.social · 11d

But you're right to say there may not be a financial case - on one hand we have reducing use, may pay for work, on other we have big important switches from fossil to elec, like heat pumps, which are expensive and don't necessarily pay for themselves

Alan Clarke @alanclarke.bsky.social · 11d

No, it was opposite - higher interest rates, in order to make money for private finance rather than subsidise, as i recall

Alan Clarke @alanclarke.bsky.social · 11d

No - builder saved few £100 but when installing a heat pump quite probably cost effective to scrap some of the rads and fit new ones

Alan Clarke @alanclarke.bsky.social · 11d

still frustrating to see a new house on gas with small radiators like this, and on microbore pipe as well:

Alan Clarke @alanclarke.bsky.social · 11d

Having worked on PH houses for years I now think with heat pumps the sweet spot is no longer at 15 kWh/m2.a but with PH we have a design approach which gives us better air quality, comfort, and removes risk of condensation and mould.

(and we can design and install MVHR that is quiet and efficient)

Alan Clarke @alanclarke.bsky.social · 11d

I've been looking at a newbuild house relatives just bought. Fabric insulation is OK really, airtightness is 7 ach at 50Pa. Could have been 1 ach for couple £K + knowhow (then add continuous mech vent). Thermal bridge at windows is big and not expensive to build better.
Also has gas boiler - ahhg!

Alan Clarke @alanclarke.bsky.social · 20d

Especially puppy farmers

Alan Clarke @alanclarke.bsky.social · 20d

Thank you so much

Alan Clarke @alanclarke.bsky.social · 20d

Like Strava - using words from a vocab common to both sides of atlantic but tone is quite alien to brits

Alan Clarke @alanclarke.bsky.social · 23d

Yes rigid duct is only way
Also I'm not really sure teeing two extracts against each other won't just end up exhausting into the other bathroom, so the current arrangement has advantage there!

Alan Clarke @alanclarke.bsky.social · 23d

Newbuild ventilation loveliness! Ensuite and bathroom extract were teed to same external terminal - flexi duct broke already and both now vent into the loftspace