Air conditioner "standby"

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Re: Air conditioner "standby"

Postby karlajensen » Wed Mar 30, 2011 12:24 pm

My Panasonic "genius" Microwave does 50W on standby.

I actually got onto Panasonic and said "Genuis" alright this sucker is costing me 50x24 = 1.2KW/ day
which = $95.92 a year or a whopping $165 a year if you consider lost PFIT income.
BEFORE I've done so much as warm a pie!

There is no reason you cant install an isolator switch local to the unit on the inside of the house, obviously would need to be better than the one in the pic but no problem really.
Given the 120W number quoted above it doesnt take a rocket scientist to figure out that $150 for a sparkie to fit a switch would be a very cost competitive option to leaving it on all the time.
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Re: Air conditioner "standby"

Postby bpratt » Wed Mar 30, 2011 1:35 pm

karlajensen wrote:My Panasonic "genius" Microwave does 50W on standby.

Thanks for the suggestion. I would never have thought that a microwave on standby would consume so much power.

Might have to get myself a plugin meter and go around the house to see what I can turn off.
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Re: Air conditioner "standby"

Postby Smurf1976 » Wed Mar 30, 2011 7:17 pm

What's wrong with putting a good old fashioned switch on appliances? Why do we have this farce of a situation where we have whole power stations running day and night just because we can't put proper switches on appliances these days?

Even where there is a proper switch, it still only seems to be used to activate a "standby" function instead of actually turning the device properly off. It's a ridiculous waste of natural resources, even without considering matters of CO2 emissions, nuclear waste, damming rivers and so on.
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Re: Air conditioner "standby"

Postby Jimbo007 » Tue Aug 16, 2016 1:05 pm

I don't know whether people have come to the correct conclusions in this forum. I installed a 1 HP Fujitsu split system in my home about 8 years ago and also noticed on a plugin meter that it's drawing about 50 watts on standby, however at first power on in standby, the consumption is nil so there is clearly no heater involved. I am in Canberra where winter temps regularly fall below freezing. The standby power is only apparent after the A/C has been used and placed in off mode with the remote control. When the power plug is removed, a rush of gas can be heard in the unit so presumably this consumption is some kind of electronic non return valve, the unit is reverse cycle and under operation, consumption has been observed as low as 280 watts.
After unplugging from power and reconnecting straight away, this 50 watts is non existent until after next use. Repeat this process each time and you will resolve this problem.
It is an inverter type A/C.
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Re: Air conditioner "standby"

Postby Warpspeed » Sun Apr 16, 2017 4:03 pm

I am not an air conditioning professional, but a few years back I did a fair bit of study on the subject.

The problem with any air conditioner, reverse cycle or otherwise, is that when the unit is switched off, especially over long periods, the refrigerant gas (as a liquid) tends to migrate either to the coldest location or the lowest location.

Think of it as boiling and condensing, where the fluid boils away from the hottest part of the system, and condenses at the coldest part of the system. If the temperatures are about equal, the liquid refrigerant will tend to accumulate (drain down) to the lowest place it can find.

What you don't want is for all the liquid gas to end up in the compressor, either the sump, or within the cylinders.
If it tries to start up under those conditions, one of several very bad things can happen. The motor can go into hydraulic lock and risks burning out if a fuse or circuit breaker fails to protect it, or more likely the reed flap valves in the cylinder head can be damaged or broken.

Many split systems that are installed with the compressor outside probably at ground level, in cold climates need some kind of sump heater to protect the compressor. If the compressor is roof mounted in a warmer climate, the problem is much less likely.

Any packaged system such as a window air-conditioner or domestic refrigerator or freezer does not suffer from this problem, as most of it will track ambient temperature pretty well when it is off. Its mainly an issue with split systems, especially in cold climates where the compressor is located well below the height of the inside unit.
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