Thursday, October 14, 2010

Voltage Optimiser coming

13 Oct: I have decided to go ahead and instal a voltage optimiser. Starting off a while back the size of a fridge, they now seem to reduced to the size of a consumer unit and cheaper too, and I'll get a good deal on the installation cost. Let's see if it will make a difference.
The unit will come from a manufacturer called VPhase.... installed by a local company. hope it works.

Our house is totally heated by electricity (i.e. the Heat pump getting what it can from the Earth and from Sunboxes) and the heatpump and the associated pumps are all motors. As this is where the greatest saving can be found, I hope that we might get at least the 10% that is offered, and perhaps more if we tune it down to 220 volts AC. The voltage in our house is a consistent 248 volts, way above the norm of 230 volts AC. All the devices we have, apart from the oven would work just as well at 220 v, but using 10% less energy.
  For people using Gas central heating, HW and cooking, the 10% saving is only of a smaller amount, the electricity they use for power and lighting. As our heating, DHW, cooking, lighting and power are all electric, 10% of a much larger amount seems to be worth going for.
  It's possible partially, to decide what to regulate. We will not regulate or interfere with the PV roof (would be illegal because the meter is governed by OfGem), and we will not change the oven (would make it be slower to heat) - the main culprit that needs regulating is the heat pump which is 2/3 of the total house consumption annually! All the things on the general ring main (computer, TV, fridge, modem, printer, power tools etc) would work just as well, but consume less.
  As usual, all results will be monitored and published.


  1. David,

    Don't count on a 10% saving from the heat pump - any 'excess' power drawn due to over voltage ultimately is released as heat from the motor coil in the compressor. This same motor is cooled by refrigerant flowing through the compressor, hence the 'excess' heat is transferred to the refrigerant i.e. is in effect a heat gain to the refrigeration process. - how this effects the thermodynamics and optimum vapour cycle is a larger and more complex argument.. .... .. you may see some saving, but its not as simple as somparing the situation to a motor, which has the sole function of producing motive power (and therefore heat is waste) - your motor produces motive power and by virtue of the cooling recovers heat. I suppose you could argue that the lower voltage would ulimately give a lower shell temperature but again the heat is being released to your dwelling, given that the heat pump is inside the house.


  2. Chris,
    Hmmm.... I am rather committed to it now, cant disappoint the lads who will install it. There are five 'motors' with this, and 4 of them are Wilo circulating pumps (g-loop, rad loop, external floor loop, loft pump). But your logic on the compressor is unassailable.
    Im prepared to give it a go.
    Hopefully the free heat we get from the sun will be helping the figures at the end of the year.
    Thanks for writing, hope to meet again soon.


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