Marvin

As recorded Item Low High Typical average per hour kWh used total hours kW per hour 24 hours Fridge freezer 0.050 0.506 0.1 0.130 25.64 197.50 0.130 3.116 Freezer 0.002 0.293 one or other 0.070 1.71 28.25 0.061 1.453 Both are auto defrost....

Hi @TerryE We have also been looking at energy use figures and its quite interesting comparing how homes work. Our bungalow floor area is 104m2. I monitored the outside temperature hourly using our weather station and compared the results with the local weather station which is only 1 mile away, and sure enough the temperature records were the same so now I just use their data. We measured the daily power demand for as many appliance as possible in our home and keep daily records from when the ASHP was installed. Our average over a day, lowest background power use, is about 300W continual We have east and west facing windows and this gives major solar gain - even during winter on bright days. Our total energy purchased in a year will be about 3400kWh and PV production about 6600kWh so 10k potential. The ASHP uses about 1840kWh a year. The car uses about 640kWh a year These we measured: The MVHR uses about 262kWh a year The fridge freezer uses about 120W an hour or about 1000kWh a year The freezer uses about 550kWh a year. The sky box uses about 280kWh a year The router uses about 130kWh a year. So minimum energy used 2,200kWh a year! Here's a useful link for those who wondered what household item uses what power: https://www.electricalsafetyfirst.org.uk/guidance/safety-around-the-home/home-appliances-ratings/?gclid=CjwKCAiA2L-dBhACEiwAu8Q9YGohisCTL8TQ-HJ_pPVFchK3PdnWzEwFaSzpcjK6f0lcE7iBMI3GPhoCOxIQAvD_BwE Also the more cooking and laundry done in a day the less heating seems to be required! During the winter the the daily non heating use increases but not between 10pm and 8 am so this has to do with equipment use. I noted that the fridge/freezer uses less energy during the winter! Marvin

Sadly no room for more PV unless I use the north facing roof but our RWH runs on 12 volt system with 2 panels on the shed.

I would not use foam. I have used mineral wool. Without fluffy, when the bath is full of hot water, the air underneath warms up, so I believe it keeps the bath warmer longer. That and making sure the space under the bath is airtight. M

Homework! Installing battery backup.

Hi @Question The first thing I would look at is the chimney stacks. Its very difficult to decide such a thing. 30 years is a long time. I know that we didn't like the idea of replacing it in 10 years time. However we planned to install PV panels on the roof so didn't want to do it after that. We had the same decision when we bought our bungalow. I looked at the other properties around and noticed problems with mortar coming out of ridge tiles joints etc, and the roofing felt in ours was not so good especially over the soffit so we ended up replacing the lot. I felt happier using dry verge and dry ridge systems which avoided relying on mortar. But as @ToughButterCup says a proper independent inspection is best.

It also depends on the quality of the materials and installation to start with.

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.