'Power Saving Voltage Conditioners'

[grim]

I've seen a number of the above units now being marketed for home use. It makes some sense if you were in a large building with a lot of traditional lighting units to run the lighting circuit at 220v or so, to reduce power consumption, but the ones I have seen recently are designed to drop the entire house supply to 220V.

As most of the main consumers of power in the house are thermostatically controlled heating units, cooker, immersion heater, tumble drier, electric fire, kettle, then they will just be on for longer if the volts are lower. It still takes the same kilowatts to boil a kettle.

Add to that much of todays electronic items are running from switch mode power supplies, which don't really notice any difference in supply voltage, where are these savings being made?

Is this just the kings new clothes? are they preying on peoples small knowledge of electrical principles?

The only item i can think of in my house that would 'benefit' is the pump in the pond. but i could get the same benefit by buying a smaller pump.

I guess light bulbs may last a little longer too, but it seems an excessive way of saving a few pence, when you have a big auto transformer running 24/7 burning up Watts

Have i missed something, or is this a gravy train i should jump on and rub my hands all the way to the bank?


This sort of thing

 

[Diver300]

More energy is used by non-heater loads, as they are on for longer periods. Many appliances will benefit from those sort of devices.

How much power is saved is debatable. Testing is quite difficult because other thing vary.

 

[MikeMl]

I think it is bull crap. The only possible savings will come from incandescent lighting, and only during times when the line voltage is higher than the device's internal set point. If I was willing to get by with less light at any given location, I would be better served by replacing a light bulb with one of lower wattage. At least a 60W lamp operated at its rated voltage puts out the correct color temperature. A 100W lamp operated at 90% of its rated voltage puts out a pasty yellow light.

Any thermostatically controlled load (fridge, freezer, water heater, furnace, air conditioning) will just run longer at reduced voltage, for no net savings. An AC induction motor will just draw more current at reduced voltage, so no saving there.

All devices utilizing SMPS are essential constant-power devices, so no savings there.

btw-I watch the AC line voltage at my location. I see 121.0V ± 0.25V at my house.