best way to exploit 'Cosy' tariff?

[Post and beam]

Having only just moved into our new house we are on the standard Octopus tariff. We run all day 'long and low' with a flow temperature not much above 30 degrees.  A little higher for some of last week when the temperature dipped below -2 for a couple of nights.

For those of you happy on Octopus Cosy how do you adjust your time periods to best exploit the triple cheap slots during the day? Do you charge to a higher temperature during them for example.

 

Thanks in advance as always

keith

 

[JohnMo]

Best way to really exploit Cosy is with a battery.

 

Without it, I would look to program the heat pump off in the expensive store at tea time as a first step.

 

Some only run HP in cheap slots, at elevated flow temp - batch charge floor in 3 periods, but if HP is well sized for house this may not yield a good result, as it cannot output enough energy to satisfy 24 hrs house energy demands in 8 hrs. But a downside if you could, without some sort of look forward (weather forecast) and the energy needs, it's easy to overcharge the house with heat and use excessive energy, that's not needed. You may also get a yo-yo of house temperature.

 

I also tried running at an elevated flow temp during cheap periods and WC the rest of the time, didn't really work for me.

 

The other downside of making the HP run harder, in cheap periods, is of the 2 slots, are when it's the coldest parts of the day, so defrosts are likely and CoP can be rubbish.

 

So low and slow may be cheaper overall.

 

The downside of high outputs, in cheap periods, without careful control, you actually use way more energy that you actually you need.

 

Have a play with settings and see what you get out of it.

 

Would say careful tuning and optimisation of the installed system my yield better results.

 

[Post and beam]

Thanks dude, thats sort of what i was thinking.  The half price during the cheap periods sound attractive but, like you,  not sure its going to work out.

For the first couple of weeks here we were getting high 5'S for COP.  Last week it fell to high 3's while the temp was about -2. These are reasonable numbers i think considering the short sample period.

I will look for an Economy 7 type deal i think. Probably a better fit to low & long.

[JamesPa]

32 minutes ago, Post and beam said:

Thanks dude, thats sort of what i was thinking.  The half price during the cheap periods sound attractive but, like you,  not sure its going to work out.

For the first couple of weeks here we were getting high 5'S for COP.  Last week it fell to high 3's while the temp was about -2. These are reasonable numbers i think considering the short sample period.

I will look for an Economy 7 type deal i think. Probably a better fit to low & long.

If you have an EV then the EON Next Drive (or Next Drive Smart) is hard to beat.  6hrs (was 7) of cheap electricity (7.5p) and not much of an uplift daytime.  If you dont have an EV and have a Vaillant heatpump then EDF heat pump add on at 15p for the consumption of the heat pump only is worth considering.

[Post and beam]

Newly built house this year so an EV charger was mandated but i dont have an EV car. I do have a Vaillant 5Kw though.

[Andehh]

2 hours ago, JamesPa said:

If you have an EV then the EON Next Drive (or Next Drive Smart) is hard to beat.  6hrs (was 7) of cheap electricity (7.5p) and not much of an uplift daytime.  If you dont have an EV and have a Vaillant heatpump then EDF heat pump add on at 15p for the consumption of the heat pump only is worth considering.

 

 

We use it, but don't have an EV.  I find it cheaper then Cosy... Think I just added my neighbours EV when asked what I drive. 

 

We run hard for the cheap slots, then add in a couple of hours during mid afternoon to top up as and when required! COP is reduced, think we're around 3.1ish, but I'm comfortably it works out cheaper this way.

 

The 50mm screed and insulation means the temperatures don't seem to drop. 

Edited 17 hours ago by Andehh