Dave Jones

9 manholes is a bit excessive

sure its not 48x100 which is bog standard 4x2.

we are using the Zehnder CW6, not fitted yet so cant give you any feedback. https://products.zehnder.co.uk/en/product/zehnder-cw6

all depends if its a warranty inspection as well. They very anal on those and getting worse as soo many warranty claims due to poor workmanship on the big sites.

yep 4x3" although many of the legoland estates are using 4x2... Dont forget tie down straps every 1.8m and half lap any joins.

if they havent specified what sort of survey in the conditions then do the cheapest (desktop) and crack on.

still fail them. remember common sense is never common when dealing with building control.

building control should fail it. grey above only.

post the whole frame U value datasheet for the windows.

https://www.developers.openreach.co.uk/

wow great work! Any tips to get started on it for a non techie ? Also how does this stack up with mvhr where you dont want open windows ? thanks

mixergy claim their plate heat exchanger is more efficient than a traditional coil. Not sure by how much ? As its external I guess it could be bolted onto a standard tank/used to heat two tanks with valves ? https://mixergy.co.uk/news-and-insights/mixergy-heat-pumps-faqs/

was looking at these yesterday and noticed the flow rate from them. it wont be enough. Will continue looking for tanks with larger flow but may make more sense to split the tanks so each supplies 2 of the showers. https://www.cylinders2go.co.uk/shop/renewable-energy/500-litre-telford-tempest-heat-pump-cylinder-twin-immersion/

plastic stick on chimney, classy.

the upstand actually can sit on top of the boards, a lot of ufh installers use the sticky stuff which is really thin. Use Marmox blocks as the first course and you dont have to bother with any upstand. They are a better U value than the insulation and stops the internal walls becoming a massive radiator leeching heat from the floor. https://www.marmoxonline.co.uk/en/thermoblock/160-marmox-thermoblock.html

hahaha. you only need a CSCS if you planning on going to work for taylor wimpey doing sitework. utterly pointless for a diy'r

they understand it all right, they smash them out as fast as possible and couldn't care less how its done as long as its quick. This normally means butchering the frame by drilling straight thought it, copious poor U value silicone and trim. No care about air tightness, sitting the frame correctly in the insulation zone, using straps and pulling out packers to avoid cold bridging etc

thanks for the useful replies. Doesn't look to be too difficult to accomplish. Using a single 500L unistor as a a start, even from completely depleted it would take 3.5 hours of pre-heat from the ASHP followed by 1.9 hours of immersion topup for a total of 33.1Kwh . That's assuming only 6kw of heat from the ASHP which is pretty low.More than feasible overnight on cheap rate or top up over the day from PV. Should capacity be an issue then can allways add another little smaller tank and still have plenty of spare capacity on the mains/heat pump. Now for the hard part, the controls...... Requirement 1. - need the above hot water to happen irresepective of time of year. Requirement 2. - Where house stat calls for heat it need to be supplied, low flow temp, no zones, 3 degree nightly fallback. Requirement 3. - cooling, still need req1 to happen but also need heatpump to reverse and put cold into ufh and supply mvhr chiller unit. As its likely to have an excess of solar heat the tanks to a much higher temp (90c?)with immersion only to give more useable and negate the need for heat pump to provide hot water? Asking the impossible for a control system to do all the above automatically ?

thanks for that, ive got some reading to do. Would I really need such a big lump though ? so some more fag packet math: Assume a single 300L tank. Based on incoming mains temperature 8C. Step1: Target for the ASHP to increase the cylinder temp to 45C an increase of 37C. Would use 12.9 KWH of electric. At 6kw of power per hour from the ASHP would take 2.14 hours. Step2: Target for the immersion to increase cylinder temp to 65C and increase of 20C. Would use 6.9kwh of electric. At 6kw immersion would take 1.16 hours. Not factored in the heat recovery but would make step 1 much faster.

so some more fag packet math: Assume a single 300L tank. Based on incoming mains temperature 8C. Step1: Target for the ASHP to increase the cylinder temp to 45C an increase of 37C. Would use 12.9 KWH of electric. At 6kw of power per hour from the ASHP would take 2.14 hours. Step2: Target for the immersion to increase cylinder temp to 65C and increase of 20C. Would use 6.9kwh of electric. At 6kw immersion would take 1.16 hours. Not factored in the heat recovery but would make step 1 much faster. So not an insurmountable task ? thats if my math adds up.....

this is the waste water heat recovery unit im planning on using. basically plumbing all the shower wastes to it. https://recoupwwhrs.co.uk/documents/Recoup_Pipe_HEX_Be-Technical_Specification.pdf

all the showers waste water will be run through a waste water heat recovery column which feeds the tanks. All helps right

wont find a decent trade on day rate.

already have the Powerwall, will be taking it from our existing place. will be fitting approx 9kw of solar as its relatively cheap and quick payback. yes 3 phase (all new builds in western powers area are required to be 3 phase now). must be a calculator somewhere that tells how long to heat X volume of water to X temp in kwh .....

its a very nice feeling!