To Optimise or Not?

[SRE]

Not many months (maybe even weeks ago) energy optimisers were seen as a waste of money, the general conclusion was that they didn't work. Now they are the bees knees and everyone is installing them. Which is it? Manufacturers make the usual claims, when I read more general info about them on the web they don't get a very good press. I don't want to diddle our customers for the sake of making a few quid and I'm going to try one out for myself but which one and why - if they were all rubbish not so long ago.

Just trying to get my head round all the options ...

 

[JulianC]

Mine works for me. I shall say no more on the matter as I am a sensitive soul and easily upset.:bigcry:

 

[SRE]

Great - what did you put in and how long have you had it

 

[JulianC]

Voltis fitted at the beginning of the year. Read all about my lies and misguided stupidity here :rofl:: http://www.electriciansforums.net/p...-energy-forum/55853-voltage-optimisation.html

 

[Gavin A]

no reason at all to doubt that they work on suitable loads such as pumps, fans, compressors etc through actual efficiency gains. I suspect a significant amount of the savings are actually from lighting where the savings aren't exact efficiency savings, but just lower power draw resulting in lower light levels, but at a level the customers don't really notice.

We're installing an Apex unit (similar in spec to the voltis) this week for a customer with a pool, with a 24/7 massive fan operating, plus pumps, compressor etc. and around £3k a year electricity bill. To me that's a no brainer, it's going to be less clear cut for more standard houses, and a lot will depend on the actual grid voltage, consumption levels and the proportion of consumption that's resistive heating vs the stuff that VO will impact on.

 

[Worcester]

Bear in mind if the compressors are inverter controlled, or are multistage they are unlikely to make a saving.

We have just surveyed 15 supermarkerts (we already did their PV ) to either install VO or LED lighting, - it's not worth doing both as the VO won't save anything on the LED lighting, it also wont save anything on the T5 lighting and will only save on SOME T8. (We also put dataloggers in for a week to monitor voltage and power quaility)

Also some of the sites have inverter controlled or multistage compressors on the refirgeration units, once agin they won't save much on the VO - see snapshot of survey sheet for EXCLUDED loads.

So the VO compnaies don't like us proposing the LED lighting ,as their systems are designed to tke full load (no such thing as bypasses here ) the cost saving go through the floor if you have to take the lighting loads out.

It also depends upon the incoming voltage - the higher it is the better the savings, when we've got an incoming down at 235 volts, we don't bother doing the rest of the survey!

Don't get me wrong, on SOME sites (5 out of the 15) it is the right solution, on 10 out of 15 it would have been a white elephant, the problem is it a bit like solar some people are overselling it. You are welcome to use the attached as part of your own survey / cost analysis.

As for productsfor domestic use, - if it adds up, I like the construction, warranties (£100 cash back if it doesn't save 10%) and the price of VO4Home, that's just personal

 

[Gavin A]

Interesting, thanks. So what would inverter controlled compressors look like / be fitted in? Latest generation high efficiency fridges, air con etc.?

It's definitely not an issue where we're installing, I've been inside the swimming pool unit, and it's about as low tech as they come, despite apparently being a top of the range unit 10 years ago.

Our sparks reckon they record both the nominal voltage and actual voltage on all their test sheets, so I think we're going to be working our way through them checking for anyone with over 240V supplies, and see if we can remember how much space their was near the consumer unit etc. before offering them an install if their consumption levels are high enough. Something like that anyway.

 

[Gavin A]

btw - wrong thread and all that, but Immersun are apparently revising their firmware so the timer can be used to run both circuits, after I pointed out it wasn't going to be L8 compliant on a dual immersion tank where the 2nd circuit would logically be the lower immersion, and it's the lower immersion that would need to be on a timer for L8 reasons.

It's for a football club's showers that are all electricly heated, so L8 both applies as it's nondomestic, and is actually quite important as it's for showers which would aerosolise any nasties.

 

[Worcester]

So what would inverter controlled compressors look like / be fitted in? Latest generation high efficiency fridges, air con etc.?

Yep, a lot if not all of the ones that do 'soft start' have them plus most of the Air source heat pumps (air con in reverse )