Balancing solar and Air Source Heat Pump

[Countrypaul]

Another aspect to invstigate is air tightness of the house. Do all the windows and doors seal properly, are there any air leaks around penetrations through the fabric of the building (the thermal envelope). Do you have any open chimneys? - a major source for heat loss if you do. If the house is well sealed you will probably need a ventillation system, in our case we hae an MVHR (Mechanical Ventillation with Heat Recovery) this warms incoming air from outside using the warm moist stale air from inside. Air is ducted to supply fresh warmed air to living rooms and bedrooms, with the moist tale air ducted out from bathrooms, kitchen, utility etc.

As the insulation in a house improves the air leakage becomes a more major source of heat loss. most MVHR systems seem to be in the 80-90% efficientc range.

Cold bridging where pipes pass through walls inside to outside also becomes significant as insulation and air tightness improve. All pipes into/out of our house therefore go down through the ground floor and underground. My fathers house has lead soil pipes from inside WC to outside connecting to the cast iron soil pipe - I suspect amongst the worst options you could have.

[AE-NMidlands]

Cold bridging where pipes pass through walls inside to outside also becomes significant as insulation and air tightness improve. All pipes into/out of our house therefore go down through the ground floor and underground. My fathers house has lead soil pipes from inside WC to outside connecting to the cast iron soil pipe - I suspect amongst the worst options you could have.

actually lead is a poor conductor of heat at 35, <10% of copper at 386. Al is 239.
I am surprised how poor lead is because I once worked on some thermostats which were stuck to copper pipe with thermally conducting Araldite, which turned out to be just loaded with lead powder. I ssupect it was chosen because it wasn't very reactive.
A
(and no-one has yet commented on how much Ripple energy might offset the costs of what you need for a heat-pump in winter. Maybe waiting to see how it turns out next winter?)

[Countrypaul]

Cold bridging where pipes pass through walls inside to outside also becomes significant as insulation and air tightness improve. All pipes into/out of our house therefore go down through the ground floor and underground. My fathers house has lead soil pipes from inside WC to outside connecting to the cast iron soil pipe - I suspect amongst the worst options you could have.

actually lead is a poor conductor of heat at 35, <10% of copper at 386. Al is 239.
I am surprised how poor lead is because I once worked on some thermostats which were stuck to copper pipe with thermally conducting Araldite, which turned out to be just loaded with lead powder. I ssupect it was chosen because it wasn't very reactive.
A
(and no-one has yet commented on how much Ripple energy might offset the costs of what you need for a heat-pump in winter. Maybe waiting to see how it turns out next winter?)

I agree lead conducts much les than copper, but it is much higher than rigid PVC by about a factor of 200 (35 vs 0.15) which i suspect is the most common material for soil pipes today. Was cast iron (55) ever used through walls for soil pipes ?

I suspect the movement of air in the pipe also contributes to the loss of heat with soil pipes, but no idea how much differnce it makes.

[ClockmanFRA]

After 21 years with our sustainability project here in France, i have given up on Heat pumps.

Why?
1. Recent EEC rules and regs implemented last year, means i can no longer install a Air source heat pump as it contains a refrigerant. And i would need an installer certificate and a company registration document just to purchase the machine itself. The concept was sound originally when the refrigerant was very harmful to the environment, but nowadays its based on a LPG type, however the heat pump industry seem to be on a good money spinner. And its very doubtful that rules and regs will be lifted on modern LPG refrigerants.

2. We have had a redesign on our latest 3 bedroom restoration re-build project, the last of our 9 buildings. And gone backwards to our tried and tested and working tech of the heating a element wire in the floor base slab we have on other buildings here, and heating it from PV during the day and it gives out its heat during the night, i.e. the old Storage heating concept.

3. It was the realisation of paying a registered and Government approved installer about £1500 just to come and bolt 2 Air source heat pumps down on my concrete slab, and i connect the Air flow ducting. And £1400 for each heat pump, so the Air source heap pump project became utterly stupid, and that money would go towards more PV and direct electricity for our required heating power requirements. In fact at Christmas we bought a full pallet of 36 Trina 400w vertex panels direct from China for slightly cheaper costs than the heat pumps. But Yea we do have plenty of space for more PV arrays,

Yes, we do have Air Source Heat pumps with water heat exchanger that i installed 4 years ago for heating to 33c our Salt Swimming pool. Interestingly they are not so efficient as the manufacturers data suggests. When they pack in after 10 years or so i will replace them with direct heating element type heaters and a few more KW's of PV.

Just my 2 penny's worth.

[nowty]

....................................... In fact at Christmas we bought a full pallet of 36 Trina 400w vertex panels direct from China for slightly cheaper costs than the heat pumps. But Yea we do have plenty of space for more PV arrays,

ClockmanFRA, what's your annual PV yield in kWh, preferably your prospective yield including all those extra panels !
I want to add you to my secret list of "Camelot Members Annual Green Electric Generation"
PM me if you'd rather not say publicly.

I'm about to do an update to the thread, your bound to bump it up nicely.

https://camelot-forum.co.uk/phpBB3/view ... f=13&t=922

[ClockmanFRA]

Hi Nowty,

On average our total used KWh generated Renewable energy here is 15859kwh per year.

Although over the years this has gradually improved as we enlarge our systems.

Also we have 9 individual buildings, on our own Mini Grid, these have their own generating capability’s and getting actual true power used data is not as straightforward as it seems.

2 years ago i finally managed to get all 3off our wind turbines individually metered.

Mrs been nagging me for years about data.

Since 2008, when i started meters on our stuff, we have saved ourselves about £70,000 in electricity bills. And as everything we do has to be cost effective; we have only spent about half of that on capital costs of the RE equipment.
Design, Installation, electronics, electrical, power electronics, mechanical engineering, builder, structural engineering, solar monkey, Research and development, general dogsbody. ME !!! hahahahaha!

I trust this helps. Are you claiming RE Credits? hehe.

[ClockmanFRA]

Nowty, just for you.

[thedoomguy6312]

IN terms of insulation, I would say the house is pretty good. I have a small FLIR camera and have addresses some of teh worst spots. I may replace some of the window double glazing panels. When we lived in switzerland, we had teh heat exchange system but this would mean re ventilation the house?