How much electricity is my fan/AC using?

rookoo

I'm having a bit of an argument with the bill payer at the moment, as he seems to think the small tower fan I use to keep cool is gobbling up electricity, and is in fact an AC unit.

The bottom of the device says the item uses 35W of electricity, which as I understand it, is pennies in the long run.

However, he doesn't buy it, and says it uses more power to cool the air etc.

How can I get to the bottom of this?

Jonesya

You point out its only a fan and show him the label again.

Alternatively you buy a plug in power monitor and prove what power it uses, they're not that expensive.

rookoo

I suppose the thing is I don't know for a fact it's not an AC. Though I associate AC's with big tonne boxes that attach to windows. Plus he's an electrician so I tend to defer to him on this stuff. Though he's obviously capable of being wrong and I can't find any reason why it'd be lying about using 35W.

Guess I'll try to find a way to measure the power use. Cheers.

Ectophile

There are some "air conditioning" units that are basically just a fan and a container of water. The evaporation of the water is supposed to produce a better cooling effect than the fan alone.

https://en.wikipedia.org/wiki/Evaporative_cooler

hd216

As you've said, the label should state the maximum power draw - it could well be less than this during normal operation.

Assuming you ran this thing 24x7x365:

35w x 24 hours a day = 840 Wh
840 / 1000 = 0.840 kWh
0.840kWh x 365 days = 306.6 kWh per year

Using a range of £0.12 to £0.18 pence per kWh this would cost £36.79 to £55.19 per year; and as I've said the above calculation is based on it running non stop for the whole year!

ariba10

A normal fan does not cool the air it just moves it.

psychic_teabag

An AC can only cool something by transferring the heat somewhere else. Typically, a box outside. (Compare to a fridge, which transfers heat from inside to outside, via the radiator grill on the back.) Possibly by using the heat to warm up something else (such as some cold water you'd have to replace.

What is the net effect of running a fridge with the door open ?

Clive_Woody

List the make and model of your fan and someone can verify if it is an AC unit of some kind or just a fan for blowing air around.

rookoo

Well, putting the model number into google results in nothing, it's a next tower fan.

hxxp://i.imgur.com/smWwKEU.jpg

Doesn't really look as if it's doing anything with water to me. looking into the back, it just seems like a motor for turning the fan.

chrisw

https://i.imgur.com/smWwKEU.jpg

It is a 35w fan, no more, no less.

PasturesNew

Yes, this is 35 watts, so it uses 1/30th of one unit of electricity per hour.

1000 watts = 1 unit
28 hours of continual usage at 35 watts = 1 unit

Whatever the current price of electricity is, this will use 1 unit in 28 hours.

1 unit is often 12-18p. MASSIVELY rounding it up would give you a cost, run continuously, of 20p per day, or £6/month. So, probably closer to £2-3/month for what you're doing.

I suspect they assume it's 1000 watts, which is what one'd normally expect/assume for any form of cooling/heating unit.

The model appears to be a bionaire bmt01 (renamed Next). Looks identical and yours says "35 watts" on the unit, so they must be the same.

Write down the maths for whoever is complaining.