HughF

These things are amazing….

Yep, I’m currently sat on a 3kW pool heat pump (no reversing valve, no inverter control) which was cheap, but I’m not sure if I’m going to go with that, plumbed directly into my vented direct cylinder (currently heated just be the Rayburn), or whether I’ll shelve that and buy another r290 mini split and use that.

Apparently the solarcoil is 10mm tube, which closely matches the 3/8” tube in my indoor unit. I’ve got some dimensions somewhere…. I suppose a dual coil direct cylinder with a pair in series would be a good bet. The biggest issue is gutting the indoor unit of all its required parts, and boxing them up into an enclosure. Mini splits don’t work without the indoor unit being complete and fault free.

As long as you ‘roughly’ replace the surface area of the mini splits internal unit pipework, and position the mid pipe sensor in the correct spot, the EEV will take care of the rest. Or were you thinking I was going to put hot water through it? I wasn’t…..

On what?

I'll DM you the link to the private group, I've generated and invite QR code (I assume you've got FB on your phone?)

I’ll probably use the Pool heatpump I picked up for £400, and just use a bronze pump (I have a direct cylinder with a couple of extra tappings)…. It’s only to give me a solar powered water heating solution in the summer when the Rayburn isn’t lit.

I'd just ignore the MCS rubbish, I expect that's what most people will end up doing. I feel their time is numbered anyway...

I'm a member of the Polish 'heat pump open source monitoring' facebook group - lots of interesting stuff going on over there with various people DIY'ing heat pumps from old AC units, and/or gutting the indoor unit of a mini split to make it into a water heater. I'm this close to getting another one of those ElectriQ r290 mini splits and running the refrigerant circuit through a coil of pipe stuffed into my immersion heater hole...

pre-insulated MLCP chucked in the floor void or rendered into the wall - job done 🤣

A really interesting discussion, good work everyone 👍

I’m fitting a fixed roofmaker luxlite into the extension. Not cheap, but they seem decent.

I don’t know if you can still buy it, but my workshop is roofed in corrugated fibreglass. It went up in ‘72 and is still fine. Edit: yep, still available…. Google will help

TP600 (in two different thicknesses, for upstairs retrofit and downstairs new install), FM330 (12 cans, I'll use it somewhere else, I'm sure) and ME508 (in two widths) ordered....

Honestly, this has been the most head scratching decision on the whole extension build.... and I still don't know if I've made the right one.

Change of plan, will retrofit the windows with humidity controlled trickle vents...

I went with humidity controlled trickle vents in the end, ordered 5 of them today. I'll replace the ones the vents that come supplied with the windows (on the windows that I fitted them to, the upstairs bedrooms), and retrofit one to each window in the extension. Whether I'll regret that decision, who knows.... But the only spot I could put a dMVHR unit would be facing the prevailing wind, and we’re in a hi wind speed area so was concerned by that aspect of the strategy.

Hmmm, window fixing straps that fit my profile seem a bit short at only 150mm long... that's a bit close for comfort with a 150 cavity. Are there any universal fixing brackets available?

https://www.airtechsolutions.co.uk/no-recovery-from-the-cost-of-single-room-ventilation-systems Discuss...

I've got white windows, and will run the render up to the windows on the outside, so any foam tape will be hidden from view. Although why can't I just gun them in with foam? Surely that's better, as it's closed cell and will bond to the window and the blockwork?

I gapped my windows for 5mm all round.... will I be able to jam the 6mm in that gap or should I take a track saw and cut the sides off the frames?

Blimey, not cheap is it.... I need 40m of tape to go all round my windows and doors...

Indeed...

Step 1, rent digger... Step 2, push it over with digger... Step 3, build it properly...