My air source

[JohnMo]

It may not be as simple as just turning down the thermostat temperature.  You should be turning down the flow temperature. Turning the thermostats down may just be driving the heat pump into short cycling.

 

With a heat pump, your thermostats should be treated as limit stops (set 1 deg above the room temp you want) not used to control house temp.  You need to reduce flow temp to increase CoP.  A badly set heat pump could have a CoP of 1 a well set up one a CoP of 4.

[pudding]

Any immersion heater on too for the heating in winter?

[SteamyTea]

5 minutes ago, JohnMo said:

badly set heat pump

I suspect this is part of the problem.

 

@tommy12398

Is there a buffer tank fitted. How many independent zones are there.

 

What is the flow temperature into the UFH.

How much insulation us there under the UFH.

Do you have thick carpets over the UFH.

Edited August 7, 2022 by SteamyTea

[Radian]

1 hour ago, tommy12398 said:

My wife does the baking for a local outside catera. So to be fair some times 2 electric ovens can be on 2 to 3 hours in a day.

Is that a double oven, two single ovens or two double ovens? A single 3kW oven might be consuming 1.5kWh and it depends on the use pattern... a 3 hour continuous baking session would consume less than several sessions throughout the day as initially the energy goes into getting the metalwork up to temperature. This is then lost each time the oven is left to cool. Commercial baking has a considerable electric consumption.

[tommy12398]

2 single ovens. Once on say on. I would say average 2 hours a,day 5x a week

[tommy12398]

The immersion heater was one of the problems. The air source was kicking out and letting the immersion heater take over. And the air souce was in silent mode for too much of the day. But that was all sorted early this year. And it has made a difference.  Its all been set up and serviced by joules, they specialise in this thing. They designed and installed it

[ProDave]

2 hours ago, tommy12398 said:

For July I've used 301kw. But exported 452kw.

You should be using your PV not exporting it.  you have not got into the swing of using PV energy have you?

 

Start by using the big appliances around mid day, on a timer if you are not in to start them manually.

 

Then fit a solar PV diverter to send surplus PV to the immersion heater in your hot water tank.  For much of the summer you will get all your hot water from the PV and could turn the ASHP off completely.

[AliG]

The ovens are around 5kWh a week. Assuming some is covered by PV it might be towards 1000kWh a year.

Depends when they are used.

 

As people have said you need to know how much energy your heat pump uses to calculate any possible savings.

 

If you are using 4-5000kWh a year of electricity in the house then the heat pump is only using 7-8000 and any possible savings would be smaller.

 

 

[TonyT]

11 minutes ago, Radian said:

Is that a double oven, two single ovens or two double ovens? A single 3kW oven might be consuming 1.5kWh and it depends on the use pattern... a 3 hour continuous baking session would consume less than several sessions throughout the day as initially the energy goes into getting the metalwork up to temperature. This is then lost each time the oven is left to cool. Commercial baking has a considerable electric consumption.

 

I started to use an air fryer for other things..

instead of the fan oven turned on for 10 minutes to reach temp to cook fish fingers for the kids then another 15 minutes , 10 mins in the air fryer no heat up time…

 

[Radian]

4 minutes ago, tommy12398 said:

2 single ovens. Once on say on. I would say average 2 hours a,day 5x a week

That could be an extra 1500kWh P/A (one and a half megawatt hours every year)

[tommy12398]

The immersion heater was one of the problems. The air source was kicking out and letting the immersion heater take over. And the air souce was in silent mode for too much of the day. But that was all sorted early this year. And it has made a difference.  Its all been set up and serviced by joules, they specialise in this thing. They designed and installed it

[tommy12398]

I suppose if ovens are using that much it does start to look like my air source isn't as bad as I thought.  It all depends how long electric will stay high. Probably fitting more solar mybe better solution 

[Kelvin]

Not if you simply export the excess PV given you’re not using everything you generate at the moment. 

[AliG]

4 minutes ago, tommy12398 said:

Probably fitting more solar mybe better solution 

This would only be true if you were using your current production but you are exporting much of it.

 

Part of the solution is using more of what you are generating at the moment. You exported more electricity than you paid for last month.

 

The biggest things you can do would be to run the hot water heating during the day and to run the ovens during the day. Also don’t run all of these things at the same time as they are more likely to use more electricity than your PV generates at any given time.

 

 

[tommy12398]

I want to fit batteries.  But seem expensive 

[tommy12398]

And remember it's summer my pannels are working well. I carnt see me exporting any electric in winter when it's-3 and the air source is working hard!

[AliG]

1 minute ago, tommy12398 said:

And remember it's summer my pannels are working well. I carnt see me exporting any electric in winter when it's-3 and the air source is working hard!

That’s right. But you could probably use over 1000kWh of exported electricity over the summer months.

 

From October that’s a £400 a year saving for free.

[PeterW]

13 minutes ago, tommy12398 said:

I want to fit batteries.  But seem expensive 

Lets start by fixing a few issues.

 

Are you on a single tariff or Economy 7..??

 

Does the heat pump controller switch the immersion on and off ..?

 

Have you got a buffer tank on the UFH..?

 

What temperature is the UFH flow set to ..?

 

Lets start with some basics …. 

 

 

[tommy12398]

Standard variable tariff 29p 

Yes when the heat pump cannot get water to temp immersion kicks in.

It's a joules tank. I'm not sure if a buffa tank is built in. But it ment to be a very efficient tank for a ashp.

Hot water set at 45°c

[tommy12398]

7 hours ago, AliG said:

That’s right. But you could probably use over 1000kWh of exported electricity over the summer months.

 

From October that’s a £400 a year saving for free.

My pannels mainly cover the cost of my summer electric.  Aswell as making me some money through excess electric exported to the grid. 

[Andehh]

Fit a solar diverter as has been pointed out, but if you have multiple ovens running for prolonged periods....your electricity bills are never going to be great.

 

Try running your house synced to the solar. Cloudy day today, but clear sky's and sunny tomorrow? Delay the dish washer and washing machine until tomorrow... etc etc

[ProDave]

2 hours ago, tommy12398 said:

Hot water set at 45°c

There should not be any situation where your ASHP cannot get the water to 45 degrees and it "has" to use the immersion heater.  I am in the Highlands which gets a lot colder than where you are and my ASHP heats our DHW to 48 degrees all year.

 

It should be possible to completely disable the ASHP's use of the immersion heater.

[tommy12398]

I have been doing that. But don't have a opinion with the ovens. We Try to stagga when appliances are on. But to be fair it's the ashp whats taking the power

[SteamyTea]

2 minutes ago, tommy12398 said:

I have been doing that. But don't have a opinion with the ovens. We Try to stagga when appliances are on. But to be fair it's the ashp whats taking the power

You have rather convinced yourself of that, without actually measuring anything.

[tommy12398]

Convinced myself out of what?