Discussion ... ASHP(Air/Air) with Solar pv ....

So, all's going well, October arrives, and Mart thinks, time to play with the ASHP. Typical generation is 220-250kWh, so probably 100kWh of export to shove through HiPpie, keep the GCH down, and top up that thermal mass. What could possibly go wrong?

Well, we've got a lodger for the next month, an utterly stunning 19month old guidedog awaiting placement. What could possibly go wrong?

He's stunning, well behaved and very, very friendly. What could possibly go wrong?

Then he meets F4 (Flash the ferocious feral feline). He looks at Flash, Flash looks back. He moves towards Flash, Flash bear-charges him to just out of paw range. He thinks this is fun, and leans in closer, Flash appears to move slightly - dog's nose starts bleeding from multiple scratches (not ideal on what is now about £50k worth of doggie). He thinks, this is great fun, barks and charges at Flash ..... many things happen in a very brief time period.

Now cats are living in conservatory, and doggie is sharing living room. [Come on Z, you've worked it out now haven't you?]

Yes - crucial to heat distribution, is having the conservatory to living room door wide open!!!!!!!

Further canine/feline negotiations have been scheduled at the UN, but Trump is keeping them a little busy at the moment.

In the meantime I've found that laying on the floor watching telly with 30kg of affectionate cuddly Labrador, is surprisingly warm. There's always an upside!

Martyn1981 wrote: »

I lost the battle today.

GCH went on this morning for 30 mins.

Notice that GCH has come on a few times this month, either in the morning or evening to warm the bedroom up when the wireless programmable thermostat has called for heat.

However, with the heat pump running in the lounge and the internal door opens to circulate the warm air, our gas use is down to a less than a third of what it was last October, at a predicted less than 200kWh for the month and electric use only up by about 20kWh, despite the recent poor PV generation.

From checking stats for October last year, it has been a bit milder so far this year, but by only a couple of degrees, but there has not been much sun

Got to say I'm loving the ASHP. Absolutely, definitely would have had to put the heating on several times during the day these last two weeks, whereas instead the living room is toasty and lots of heat going into the 'structural mass battery' of the house. Probably 75%+ from PV. Interestingly, dull days with less generation are also warmer, so less heating needed, whereas cold days are sunny. Nice.

Slightly odd to still be in shorts and t-shirt in Nov, rather than 'big boy' trousers and a fleece top, but the living room is 20.5C to 21C even with the door to hallway wide open, as I'm trying to maximise heating and minimise gas burn.

Several days barefoot too after getting wet taking the dog for a walk, but he's been matched now with a guide dog owner, so no more Labrador cuddles to keep me warm ... for now.

Just gone through first full year since having the Air Conditioner/Heat Pump installed; so able to compare year on year figures for Gas and Electric consumption.

Gas use has reduced by 5,588 kWh. That's an over 50% reduction compared to the previous year.

Electric import has increased by 344 kWh. That is an increase of 18% compared to previous year. But solar PV production has been lower this year than in 2016. Also, been using a lot of high power tools, cement mixer, etc in the garden this Autumn to extend our patio.

Use of Solar PV generated electric has increased from about 40% to just over 48%.

So with our unit rates for electric & gas we have saved £166.65 on gas, but spent £37.20 more on electric import. A total saving of £129.45 for the 1st year.