Smart Meters and Heat Pumps

markin

Spoonie_Turtle said:

Netexporter said:

I don't see how economy 7 will benefit you.   You need around 50%+ of your electric to be off peak to be viable.

Yes, E7 is for storage heaters, not heat pumps. As others have said, Octopus Cosy would probably be the best fit. It is designed to deliver heat at the least cost.

Or Tracker, as long as they read up about it first then keep an eye on the price.

(I don't understand how Cosy is supposed to specifically work well with ordinary heat pumps.)

It was released along with their own high heat, heatpump and hopefully has the control's to easily set it to not come on at peak time.

Markw

matelodave said

Have you got weather compensation activated and has it been adjusted to suit the temperature requirements of you house.

I've had a heatpump for over 13 years, coupled with underfloor heating and I would agree that the electricity consumption does increase quite dramatically when the temperature drops to freezing or below, but TBH it really doesn't happen that often that I get upset about it. Some days when its been everso cold we've chomped through 60+ kwh but generally its a lot less and our total annual electricity consumption average out at about 19kwh a day.

We are at home all day and I can't see that trying to wind the unit up to overheat the place so we can shut it down during the expensive periods for Cozy or E7 would actually save all that much money but it would definitely affect the comfort levels.

We want to be warm during the day and the evening and not so much overnight so E7 wouldn't work for us at all and I'm not convinced that closing it down during the peak time when we want to be warm and cook our evening meal would enhance our comfort levels either.

The advantage of a smart meter (ours is a SMETS 1, installed in 2017) and it works, we've always been able to extract historical half hourly readings from it, even when we changed suppliers and it wasn't communicating with the supplier direct. Since it was enrolled with the DCC about three years ago I can suck two years worth of half hourly reading from it if I so desire using the Bright app. which gives me the opportunity to evaluate my consumption to see whether a TOU tariff would suit us and so far I reckon they probably wouldn't. 

Many thanks for your reply Dave. Not sure if Weather Compensation is activated. There is no mention of it in the manual although there is a piece on the OTC heating curve which maybe the same thing? However I cant make much sense of it. The Hitachi manual is not at all user friendly and is clearly aimed at Installers. However I have had lengthy discussions with the very helpful tech team at NuHeat who designed and supplied the system but they have never made any suggestions for altering settings which could improve the efficiency. We have a Hitachi ASHP supplied in 2013 and I just leave it on 24 hours to run by the thermostat as by turning it off the floors go cool and take some time to heat up again and I cant see that timing the use would make much difference to consumption but it would make a difference to comfort. 
So interesting to know your average daily usage. We too are at home all day and our average daily usage across 12 months is 22kwh per day so very similar. On the worst days when temperatures are below zero we have used 85kwh in 24 hours.
I have booked an appointment for a Smart Meter install and now looking forward to it. 

MultiFuelBurner

Hi @Markw

To be blunt your heatpump is 10 years old and to be burning 83kwh in 24 hours is ridiculous as even at the recent -2 to -4oC temps we have hadna cop of 2.5-3  at a flow temp of 35oC which is achievable for most heat pumps.

Surely you must have tried some lower flow temps or the weather compensation settings? Have you even looked to see if the reason for the high usage is a backup electric heater (an immersion or sorts) that kicks in to reach the flow temps you are requesting?

The best way to get your heatpump to work.as efficiently as possible is to spend some time getting to know it and recording what changes you make.

It's fine to run the system 24 hours a day but what flow temp is it set to if you are not using weather compensation setting that automatically adjusts the flow temperature based on the outside temperature.

What are your thermostat set to?

What us the Hitachi model you have and kewh rating?

What is the size of your house?

What is the EPC rating?

matelodave

I'd agree with MFB, you need to understand how it works and how its set up.

Ours chunters away at around 30 degrees flow which increases to around 38-40 when it gets very cold (below 0 degrees) which isn't very often. Again, be careful that the backup/boost heater doesn't kick in, a lot of systems aren't set up very well and if your flow temps are above 50 degrees either for heating or hot water then it's likely that the boost heater will be operating on peak rate especially when the temp drops below zero.

Ours was initially set up for a fixed 40 degrees with the heater set to operate when the temp dropped below zero. i've tweaked it a lot to shut off the back-up heater and to set the weather compensation to match the heating requirements of our bungalow.

Markw

MultiFuelBurner said:

Hi @Markw

To be blunt your heatpump is 10 years old and to be burning 83kwh in 24 hours is ridiculous as even at the recent -2 to -4oC temps we have hadna cop of 2.5-3  at a flow temp of 35oC which is achievable for most heat pumps.

Yes I agree it is ridiculous. It is due to the Frost Stat on the ASHP. I have tried reducing the control thermostat to 10°C and the pump just keeps running.
Our average usage for November was 31kwh/day. I have had discussions with the tech support at NuHeat and they say there is nothing to overcome the Frost issue.

Surely you must have tried some lower flow temps or the weather compensation settings? Have you even looked to see if the reason for the high usage is a backup electric heater (an immersion or sorts) that kicks in to reach the flow temps you are requesting?

Water Supply is set to 36° We dont have a backup immersion running. 

The best way to get your heatpump to work.as efficiently as possible is to spend some time getting to know it and recording what changes you make.

It's fine to run the system 24 hours a day but what flow temp is it set to if you are not using weather compensation setting that automatically adjusts the flow temperature based on the outside temperature.

We dont have a Weather Compensation setting. Flow temp is set to 36° which is maintained on the sensor. Cant see much benefit in altering this?

What are your thermostat set to? Control Thermostat is set to 18° which maintains 20° room temp. This increases when outside temperatures are below zero regardless of thermostat settings.

What us the Hitachi model you have and kewh rating? Hitachi RHUE 3AVHN 8.2 kwh

What is the size of your house? 310m although we only heat around 2/3rds.

What is the EPC rating? EPC - B 83

Many thanks for your reply. Answers above.