Marvin

What the overlap 100mm?

I would make sure you use Waterproof PVA as there are some that are not: Although most PVA glues used industrially are water resistant to grade 2, which means they can sustain several cycles of soaking/drying without having the glue fail, they are NOT Waterproof. EVERBUILD® 506 Contractors PVA is not ok see product data sheet: https://cdn.aws.toolstation.com/items/manual/manual-everbuild-506-contractors-pva-18844.pdf I would use Everbuild 503 SBR Bond or similar. https://www.toolstation.com/everbuild-503-premium-sbr-bond-bonding-agent/p18528 Good luck M

Inflation? Is that including VAT?

Transformerless? er... This one. https://uk.renogy.com/3000w-12v-pure-sine-wave-inverter-charger-w-lcd/

MI ?

On a 12v 860Watt PV panel system do the panels need grounding to earth? The charger/inverter is charged by the mains. The panels supply some 12v power for the batteries. The inverter only supplies 240v to a non-mains circuit. No panel earth point indicated on the inverter charger. The inverter/charger relays the, mains/battery power supply earth, depending on the supply. I have an earthing rod ready...

Hot air won't necessarily be lost but cold air can be gained. Not quite sure what the second photo shows. I wonder if this didn't have coir matting in it originally. How deep down? 25mm?

Is all the floor sealed against moisture? DPC or garage paint?

24883 kWh produced. 5985kWh used. COP of 4.16? SAP suggests 14500 per 52 weeks. You indicate 16777 for about 50 weeks, So about 15% higher? 8106kWh for hot water a year is about 22kWh a day. Surely that's too much? Other more knowledgeable people will have to comment. Exactly what insulation was used on the floor and how thick? M

Hi @GHDirect Is that 300 litre tank in the garage?

@SteamyTeawill be proud of you....

Hi @john0wingnut I can understand this. We have 104m2 floor bungalow but it has good AIM (Airtightness, Insulation and an MVHR). Ducting in our cold roof has been a pain and is effected by the heat and cold, even though covered by 400mm fluffy. If I could do it all again I would make it a warm roof. M

Yes, in the future you may well be using off peak electricity for the washing machine....

Hi @gravelrash

0 volts normally means its a separate relay (activated by other power but no power in the switch!) When you look at the diagram it shows a separate source of power coming from the boiler through the relay and back to the boiler.

Yes.

Oh! sunset worked for me!

Our small whole house MVHR unit is off the floor hung on the wall. We never have a vibration noise from the unit. The only thing we ever notice is the sound caused by the fans when on boost which travels down the air vents. It will be good to see what the unit fixing recommendations are. Oh and our unit is above our bedroom and SWMBO could hear a mouse fart.

Hi @Nick Thomas Thanks the info. Very interesting. Our setup using excess PV power is slightly different: Dedicated EPS sockets for use only in a power cut. Level zero type system? ( can be used for a small heater assuming a short scheduled power cut) A level 2 type system for battery power for overnight use of lighting, MVHR, Fridge Freezer. A combination of both the above for use in a power cut. (Assuming a short scheduled power cut) We have calculated and monitored our PV excess power produced in the summer days and are aiming to use about 5kWh a night about 200 days of the year. This will be completely isolated from the mains and we hope to have the system up and running once we get on and install it.

So not good for hot water as well?

What about a split power supply using a relay? battery supply inverted to 240v

Hi @Hastings Thanks. Definitely an improvement on my design which I will add on next summer. In my design the supply pipes enter below the water level in the catch-pit and are angled to swirl the rubbish to the sides with the draw off in the centre. Next summer I hope to vacuum out the bottom of the main storage tank to see what's in there.

That's twice my whole house heat requirement at minus 3 centigrade outside and plus 23 inside. Eight times the loss per m2 floor area of mine. (104m2) Something needs seriously fixing!

You've done that already.