Energy useage/cost for average 1930s 3 bed semi?

That's over 4 winters, so about 3000kWh per year heating and hot water. Heats the whole house 24/7/365, ie it's climate control - usually set to about 19C. It comes on when needed to boost the temp to 19C, no timers nothing. It's always comfortable, never cold.

Yes, it's marginal. I'm looking at doing a bargain basement DIY solar install for the garage - 'second' panels about £35, I need to find a ~£50 used inverter and it'll be worth it just to cover standby power.

There was a cylinder in the airing cupboard. This was replaced by combined

Theo

I think for many air-2-air heat pumps aka aircon would be the way to go. I understand that as they don't need a high temperature difference they retain their efficiency at lower outside temperatures. The main issue is they don't heat the water.

Given many reports suggest that even with modifications like external shutters, we are going to need aircon, the cost, even without a grant was less than an air2water heat pump

Of course the government does not want us to have them, as they can be used to cool, and they don't solve the hot water problem

Dave

So you lost your airing cupboard, whereas I have an airing cupboard but nowhere else to take its place.

If I replaced my standard HWC with a 200 litre one, the simpson joist hangers that strap the lateral 9x2.5 inch joists to the one running along the top of the wall that is part of the stairs would probably fail !.

Idiot builders in 1976 used 4 inch round wire nails to 'fix' the hangers, with a gap of up to 0.5 inch between the butt end of the lateral flooring joists and the supporting joist sitting on an internal partition wall (also strapped at each end to another lateral pair of doubled joists). No 45 degree cross nailing with any sort of nail into the butt ends either. Real botch job.

You can seen from the distortion of the joist hangers that they are were close to failure back in 1976 (upstairs partition walls are 3 inch cinder blocks built right onto the chipboard flooring)

Didn't lose it as it's double-width. The cylinder already occupied one half, so only lost about 10% more of the total. If the install didn't have a buffer tank (it didn't need one, but the ASHP manufacturer was a bit lazy) then it would have been the same as what we had before, just with a thicker jacket on the cylinder.

Could you put a hot water tank in your loft? There are horizontal unvented cylinders, eg:

Theo

You cannot get a grant for air to air and for air con in summer.

Don't forget that until the 70s, the gas piped into homes was derived from coal and was about 50% hydrogen. Pipework was pretty much all iron.

Is that £300 per quarter or per month?

I suppose it must be per month, but the phrase "the coldest months" could suggest otherwise.

I've just paid our Jan-Apr bills, About £330 for electricity and £420 for gas. If your bills are assessed monthly, our ££750 for the whole quarter doesn't sound so bad, especially with all the electrical items which are on more or less all the time here.

We have just such a house, built about 1960, but definitely to the late

I can easily sum the bills for the last four quarters (if that's a helpful figure): £2880 (but we probably use more electricity than average, with computers an various audio-visual stuff operating on standby).

The last quarter's bills were noticeably higher than the same quarter in

you don't need it. cost is so much lower. grant is a total white wash. I am sure they put the price up because they know you get a grant...

Dave

A gas boiler can still be used to give rapid warm-up of a building, that a heat-pump may take a long period to get up to temperature. It can also help on the coldest days, if necessary. It can provide almost unlimited hot water.

Unlimited hot water for what ??

No, it's a 1976 semi, about 80m2. The airing cupboard has a standard

As previously mentioned, the lateral 1st floor flooring joists have deflected about an inch where the tank is and the ends of the same joists are badly connected to their front/back joist, so I cannot consider a bigger HWC at that location.

Loft is 37 degree pitch and I have added 300mm of insulation plus 'decking' for storage so the headroom is even less. No supporting internal walls. The eight metre span trusses sit on the front and back walls.

Other than building a side extension, I think my only option is an air->air heat pump and modern storage heaters, plus masses of insulation, then think about solar PV and a battery.

That's what I suspect. And it may be that there is simply a jumper inside somewhere that disables air-con.

Well, with a family of five, we use lots of hot water. The 40 gallon tank can need a boost and a gas boiler does that rapidly. A bigger tank is not an option, as it'd be in the way.

But at nowhere near the pressure required for modern hydrogen enriched gas.

I understand that you need planning permission for air to air.

Not for air to water.

Because the government doesn't want easy access to cooling in the summer.

Cheers

Dave R

Which brings us back to the start of the thread, more or less.

It appears that a Council is supplying a hybrid system free of charge to improve the carbon footprint of houses. However this "worthy" activity doesn't seem to be reducing the energy costs to the householder and may even be increasing them.

A link to Worcester Bosch upstream somewhere talks about adding ASHP without modification to existing systems. i.e. No larger radiators, no hot water storage. A Hybrid system.

I am charitably assuming that the ASHP will bring the radiators up to around 30-40C and then the gas boiler will top this off to the design temperature of the radiators if the house is cool/cold. In theory this should reduce gas usage by substituting efficient use of electricity in the CH.

As I have said, this looks like a fudge to me, to get an ASHP installed without the expensive infrastructure modification required for a proper full ASHP install. Otherwise known as greenwashing.

Further information awaited.

Thanks to all who have contributed.

Cheers

Dave R

I suppose what they might be doing is installing a 'high temperature heat pump'. Basically this is a two-stage unit, the first stage is like a regular ASHP. The second stage takes the output at let's say 35C and then does another compression cycle to raise the output water temps to 60+C, possibly with a different refrigerant than in the first stage. That means you can use your existing radiators etc with the 60C water, but you pay the energy cost in terms of running what's effectively a second ASHP on top of the first.

It may be that the cost of building two ASHPs in one box is now low enough compared with replacing all the radiators, but you're always going to pay for it in lost efficiency: the higher you have to run uphill to do the job, the more energy it takes.

There are also some single-stage high temperature heat pumps, using R290 (propane) or R744 (CO2).

Not sure if this is single or two stage (it's R290):

For a nominal 9kW HP (7C air in/35C water out), at -3C air you get 7kW at 35C output, down to 5.4kW at 75C output. At 7C in/35C out the COP is 4.52 and at 7C/75C it's down to 3.05.

So by skipping the one-time radiator upgrade cost you're paying 50% more on your energy bill every year.

Indeed, would be interesting to know the model of the ASHP.

Theo

Portugal, Spain and parts of France are without electricity right now.

Nothing to do with renewables. Oh no. Of course not.

No planning permission needs for a single air/air unit, but no grants if it can provide cooling (as I understand it).

Tim