Can you solve this mystery?

[Deleted User]

I have had SMETS2 meters for nearly 2 1/2 years. If Octopus cannot retrieve actual smart meter data (as happened with the Kaifa electricity meter earlier this year) then My Usage will show no data. Often missing usage data can still be seen in the App BRIGHT. Where data is missing for billing purposes, then Octopus will execute a manual data pull from the meter.

A year ago, Octopus replaced the L&G E470 100mm meter for consumers that owned a Powerwall 2 as the meter was recording reactive loads. Both the meter and the Powerwall 2 were certified as meeting industry criteria but they failed to play nicely together. I have no idea what a PIV is but might it be producing a reactive load? You will need to get in contact with other consumers who have a similar meter and PIV set up to compare experiences before Octopus or any other supplier will investigate.

https://octopus.energy/blog/perils-working-tech-innovators/

QrizB

Dolor said:

I have no idea what a PIV is ...

I'm guessing Positive Input Ventilation?

https://www.vent-axia.com/positive-input-ventilation

Some are fitted with heaters (one model I googled said 500W) but the OP hasn't said yet whether theirs is, or not.

digannio

Thanks for all the answers. It really doesn't look like it is anything to do with the PIV which in the 7 months I have lived in the house hasn't had any extraordinary impact on the bills. It really does look  like the Explore My Usage section of my account for the second day of the house being unoccupied is an estimate based on my average. The first unoccupied day is as you would expect, very low, and the second should have been very low just the same but equated to what would be an average day here using stuff as normal. So, looks like the figures they are giving me isn't based on real usage but estimates, which is, well, useless really. My IHD doesn't work properly and I'm trying to work out how to get daily historic info from the smart meter itself.

digannio

This has now reached a conclusion following some detailed checks on leccy usage on various appliances. I have to apologise for dismissing those who pointed the finger at the Positive Input Ventilation system because they were correct.

This system was sucking up large amounts of power. It is a Nuaire dri eco heat hcs with a 400w heating element and does a great job in stopping condensation and supplying clean fresh air and dispersing cooking smells. But the costs are now clear. I had the heater on a mid setting and the blower on 3 (out of 6 settings). We only moved in a few months ago and the booklet claimed an overall cost of about 8p a day (don't know when this was estimated) which includes the summer period when it often goes into standby when there is no chance of condensation.

But my checks show that continuous use of the PIV during winter on my Octopus tariff (passed over from Avro) mean an hourly cost of 4p which is 96p per day or £35 per month. Didn't expect that.

The PIV does do a good job but I've turned off the heater (which doesn't really provide hot air but is there just to take to take the chill off the cold air from the loft). I've also turned the air disperser down to level 2 and we'll see how the costs pan out now. 

Thanks for the help and sorry for doubting those who clearly had more idea than me. Mystery solved and maybe it's a pointer for anyone else with a PIV now grappling with much high energy costs these days. The estimated running costs of old are maybe no longer valid with the prices we are now paying.

BobT36

Wow thanks for this mate. This has been an interesting read, considering it was a weird topic that looked like a crappy IHD, and most posters post questions then disappear, cheers for getting back with the conclusion.

"The estimated running costs of old are maybe no longer valid with the prices we are now paying."
This is a very important takeaway. I'd seen a LOT of good stuff about those PIVs, and how cheap they were to run etc. I think these massive price rises will have caught a lot of people out in similar ways. 

Does it really work to cut down on condensation etc? Was always thinking of getting one if I got my own house, but that is a huge note on not actually being able to utilise it fully with the costs nowadays! And especially how it may not be obvious what's causing the huge drain. 

markin

It was probably installed for good reason, so monitor closely for condensation behind furniture and in corners to make sure setting 2 will do the job correctly, But the heat is not needed and is just for comfort.

digannio

When I moved into this house and was told it had a PIV, I hadn't heard of such a thing and thought it was a bit gimmicky and wouldn't work. But the short answer is that it really does work. We have very little condensation (unlike our previous house) and the air is fresh and any cooking smells disperse quickly.

It is a bit cool feeling under the ceiling diffuser and obviously there is the running costs. However the good news is that the leccy costs for me look like they have plummeted hugely now I have turned off the heater and dropped the blower down a notch. So it looks like a PIV without a heater or one with the heater turned off won't break the bank and can tick along without gobbling up large amounts of leccy.

I'll be keeping mine going now I've got things under control.

BobT36

Hmm does it make your whole house cold? (Without the heater on) or is it just directly underneath?

I have heard some good stuff about them though yeah so it's nice to know they do actually work. Just a shame the cost isn't as cheap nowadays as they used to make out!

Petriix

PIV systems are great for removing condensation, but they do that by pumping cold, dry air into the house and forcing the warm, moist air out of the cracks. The electric heating element is a pretty inefficient way of warming the air but, even with that switched off, you'll still be paying lots more to heat the space. It's a bit like leaving a window open 24/7.

There are better (more energy efficient) ways of reducing condensation. A ventilation system with heat recovery is a good choice, but nothing beats simply limiting the moisture that circulates in the living space by keeping bathroom and kitchen doors closed and ventilating those spaces directly whenever you do something which produces moisture. Avoid drying washing indoors too. 

digannio

It's just not true to say that it's like leaving a window open 24/7. I don't know if you've lived with a PIV but within six months I've gone from living without one (lots of condensation everwhere even with bathroom and kitchen doors closed) to living with one (virtually nil condensation most of the time). I know which I would choose. And it's just not true to say you need to keep the heating on because of it. Now I've turned the heater off my leccy costs have normalised.

I don't have an axe to grind, just telling it as it is for me with real life experience of  a PIV. There is hardly any condensation, less dust in the house, the air is fresher (without it being cold) and any smells, like cooking, disperse very quickly.