My air source

[ProDave]

6 minutes ago, tommy12398 said:

Just got my first payment through for July from the solar pannels. They have paid me 24.5p a kW for 511 kw exported. That's £124. I don't think that's too bad.  Mybe more pv could the answer

That must be on the Feed In Tariff then, so you are getting paid just a little less for export than your import, so not so bad.  

[Ferdinand]

17 minutes ago, tommy12398 said:

Just got my first payment through for July from the solar pannels. They have paid me 24.5p a kW for 511 kw exported. That's £124. I don't think that's too bad.  Mybe more pv could the answer

 

Can you link to your export tariff?

 

Is this perhaps Outgoing Octopus or Outgoing Agile?

 

24p per KW is more than most people get on FITs.

 

  

5 minutes ago, ProDave said:

That must be on the Feed In Tariff then, so you are getting paid just a little less for export than your import, so not so bad.  

I thought @tommy12398 had said that the solar pv had been fitted recently - ie this summer.

 

I think the tariff is a beta for Octopus playing with the Smart Grid. It looks like they are paying nearly the full wholesale price, rather than the current SEG price.

 

 

[PeterW]

3 hours ago, tommy12398 said:

Just to add a point I have set it at 45 from 49. Just seeing if it saves any electricity 

Set point for what ..??

 

Can we get an exact model number for this ASHP, and a photo of the UFH set up as putting 45°C water into UFH is nuts - there should be multiple flow temperatures depending on whether you’re into UFH or DHW. 
 

How big is the Joules tank too..? 
 

 

[tommy12398]

I will take pictures when home.  I think I'm getting mixed up with my hot water setting. Not flow temp. Is agile octopus.  So get paid fir the market rate. The joules tank is 300ltr

[Kelvin]

1 hour ago, SteamyTea said:

I think I read somethign about this.

Seemt o remember that it was 20W, then a bit more when tracking.

Is the service good though?

 

It depends on the dish. The original large round dish was much more power hungry than the current square dish. It moves the dish when setting up initially and I assume it uses beam forming thereafter. The dish hasn't adjusted itself since the initial setup. It is rated for 180W which it might use to melt any snowfall in the winter. 

 

It is excellent. I've had it installed for 3 months and it's been down for two days in that time when they had a widespread outage.  Latency is around 45ms, average download/upload is 150Mbps/15Mbps but I've seen as high as 260Mbps/25Mbps. We use it a lot for zoom/Teams meetings and it's fine. The only very occasional issue is that we might get the odd pause in the video stream for a few a seconds or so. You can see these pauses in the app. Over the course of a day it's a few seconds at worst which is fine for just about everything we do as you don't notice it. I still have it mounted on the temporary stand in the middle of the lawn. I have all the kit to bolt it to the house but it's a rental while we build so will leave on the lawn. It is very sensitive to being blocked though so needs to be clear of trees etc. 

[tommy12398]

Here's a snap shot of my pv price 

[tommy12398]

Here is a few pics of my set up.

[tommy12398]

[ProDave]

Some pipe lagging around that tank will go a long way to cutting down your standing heat loss from the hot water system.

[PeterW]

That Samsung is normally a good unit so it’s down to install or config. Can’t see if balanced cold is installed or the fitter decided not to bother, and I “think” they have zoned the DHW on the bottom and then gone for twin zone valves into your heating. 
 

Got any photos of the UFH manifold ..??

 

And have you got the installer code to access the menus ..?? Need to see what hot water is set to. 

[tommy12398]

Does anyone have a rough idea what the ashp will use in winter just for the hot water.  I'm think of having central heating off or very low. And install multi fuel stove. Will the ashp use alot less just heating water tank upto say 45°c. I know we really need proper figures, but anyone a rough idea? 

[ProDave]

We use up to about 40kWh per week for hot water in winter.  less in the shoulder seasons when the incoming cold water is not as cold, and there is solar PV to help it along a bit.

 

Very dependant on how many in the house etc and if any of you like very long showers.

[AliG]

It uses roughly 5kWh of energy to heat 100 litres of water up from 3C to 45C

 

With a COP of 3, that is going to be 1.7kWh to your heat pump.

 

You are probably going to use roughly 1.7kWh per person per day, depending on how many baths, showers etc people have.

 

The COP will drop to around 2.5 if the temperature falls below 5C, so it also depends on the outside temperature.

 

This chart gives you an idea of COPs for different outside temperatures and water temperatures, it is not your specific ASHP, but they are normal quite similar.

 

The big improvement in COP is between 45 and 40, this is why running your UFH flow at a lower temperature helps. Realistically 40C would be too cold for your hot water.

 

[tommy12398]

That's not too bad. We have to young kids so they have baths. Even if we used double this a week say roughly 300kw in winter months. Would definitely think a stove is a viable option 

[tommy12398]

All I know is we can use alot of electricity if everything is on. Over 1000kw a month. That's why I'm thinking of ashp for hot water. Stoves for warmth down stairs. We already have alittle wood burner in living room.  Looking for a 5kw for kitchen. It's a fairly high roof open plan room. Ashp always has to work hard to get that room upto temp

[tommy12398]

So when they say ashp are super efficient cop values 3 and up. Only if its not super cold outside. Our house regularly drops below 0 in winter.  As I've said earlier in this chat, with whats to come with the price caps, the ecomics of a ashp isn't adding up! But I'm stuck with it now and like everyone else will have to find ways to use less and cut costs

[PeterW]

2 minutes ago, tommy12398 said:

Only if its not super cold outside.

Most are fine to -20°C - heat capacity of air is linear down the scale. 

[AliG]

16 minutes ago, tommy12398 said:

So when they say ashp are super efficient cop values 3 and up. Only if its not super cold outside. Our house regularly drops below 0 in winter.  As I've said earlier in this chat, with whats to come with the price caps, the ecomics of a ashp isn't adding up! But I'm stuck with it now and like everyone else will have to find ways to use less and cut costs

For heating your COP should stay above 3 most of the time for heating as long as your flow temperature is below 40C. That is why people have been asking about the flow temperature. This is also why less well insulated houses become a problem as the heat loss is too high to be offset by a low flow temp and the COP starts to drop off as the flow temp increases.

 

For hot water at say 50C, then the COP will be above 3 for most of the year, unlike heating you need hot water at all outside temperatures, but fall into the low 2s when it is coldest in winter. For that small part of your demand, a gas boiler would probably be cheaper, but this is why they quote a seasonal COP that tries to average this out over the year.

 

If your house is high up and exposed with a lower than average outside temperature then you will have a modestly worse COP than some other people.

[tommy12398]

Looking at my ashp. I would say flow temp is around 30°c. That's what the circulation pump says. If that's not it how do find flow temp?

[PeterW]

20 minutes ago, tommy12398 said:

Looking at my ashp. I would say flow temp is around 30°c. That's what the circulation pump says. If that's not it how do find flow temp?

That will be the number of watts or the %age power setting depending on the pump. Nothing to do with temperature. 

[tommy12398]

It's says in the mannual circulation water temp?

If that's not it I don't how to find flow temp

[Kelvin]

Your system is identical to what I had in our old house. Your electricity usage is about 20% more in a house that’s 40m2 smaller. Our downstairs floor area was 175m2. Ours was a barn conversion. The insulation was better than average but not as good as it could have been. Our UFH manifolds (we had two) had a combined temperature and pressure gauge and a mixing valve. I messed about with flow temps and settled on 30C for most of the time and upped it during very cold periods. I also heated every room despite not using every room.
 

The house was generally warm enough most of the time. We had two teenagers in the house at the time who were never out their showers. They are both paying their own bills now so are having fewer showers for less time each shower 😂 

[PeterW]

1 hour ago, tommy12398 said:

mannual circulation water temp?

If that's not it I don't how to find flow temp

Thats fine - you said the pump hence my response. That’s flow temp 

[tommy12398]

20% more is alot. We do have young kids and they have bath's. Do you know your EPC for the barn conversion.  My wife will use part baking. The fourm here thought anywhere between 1500 to 2000kw. 

[tommy12398]

What should the flow temp be. Is mine in the right area?