# How much does 2,600 Watts of electricity cost?

#### furnace

Soldato
Me and my brother are looking at air conditioners for the room we have our PC's in - we literally sweat in here. There's one that looks good, it's "9000 BTU/hour".

There's also one that's "7000 BTU/hour" but, obviously, has less cooling power.

I've found this, to work out running costs;

Watts = Btu/hour x 0.293

So... the 7000 one uses 2051 Watts, and the 9000 one uses 2637 Watts... it sounds expensive?

My parents foot the bill, so I have no idea how much this is going to cost in electricity? I can't just go out and buy one if it's going to cost them a fortune to run

So based on the wattage, how do I know how much this will cost to run? 2,600 Watts does sound a lot - but I have no idea on the value of electricity! What do you reckon?

Cheers

#### Raikiri

Soldato
An average of around 11p per kwh would mean about £6.86 a day to run for the 2.6kw one (that's 24/7 though).

The cost varies but 10-11p is the norm I think.

#### Steeps

Soldato
if a kwh unit is about 11p, the 2600w unit would cost about 28.6p an hour

#### YoungBlood

Associate
Pretty hard to work out as it's not a constant 2kw. Will only use that when the compressor kicks in, which is only every few mins or so. Depending on if you vent it properly through the wall or ineffeciantly through a window.

As a dodgy rough estimate, with the AC in my room kicking in at 26c it costs about £2.50 a day. Have a payg meter so it's not hard for me to get a rough idea.

It's way to expensive to run all the time, I just use the fan mode mostly and only put it on AC when we have one of those unbearable days, which thankfully we have had very few of so far this year.

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#### Tomsk

Soldato
Raikiri said:
An average of around 11p per kwh would mean about £6.86 a day to run for the 2.6kw one (that's 24/7 though).

The cost varies but 10-11p is the norm I think.

And that's at full power.

24/7 @ full power is pretty unlikely in sunny Britain.

#### furnace

Soldato
Awesome, thanks

OcUK is the place to go for the answers to all of life's questions ...

#### YoungBlood

Associate
How much sunlight does the room catch? how warm is it in there now? if you don't get the sunlight catching your rooms side of the house it won't be so bad.

If it does then the AC will be constantly fighting it's self to keep the room cool, exspecialy if you plan to just vent it through a window.
Also how does the window open? sideways or lift up type. If it's a lift up type try to get a unit that comes with the venting kit designed for that type of window where it seals off the rest of the open window.

#### furnace

Soldato
It's an 'unofficial' loft conversion. So we only have one skylight which is, what, 30 cm by 40 cm or so... So not a lot of sunlight, but surprisingly it gives us enough ambient light during the day to not need to worry about artificial lighting Although that skylight is on the south side of the house - so the side the sun rises/falls.

We will vent it straight out the side of the house, through a hole drilled in the wall.

I presume that'll make things more efficient..?

We have 4 PC's running in here, and 3 people. I shouldn't imagine it has much more than 15-20 cubic meters of space...

Right now, it's warm enough for me to be sticky at the brow... however warm that is!

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#### calnen

Soldato
Raikiri said:
An average of around 11p per kwh would mean about £6.86 a day to run for the 2.6kw one (that's 24/7 though).

The cost varies but 10-11p is the norm I think.

.. £6.86 a day, or £48.02 a week, £2500.00 a year....

Even if it's only on a fifth of the time (How much are you in there?), thats a serious amount of money! You'd almost certainly be better off in the long-run getting a more efficient PC and just leaving the window open.

#### YoungBlood

Associate
Yeah that sounds perfect. I imagine it would save you alot of money over time having it vented properly.
If it gets a little chilly up there in the winter, why not get one with a heating function too

#### furnace

Soldato
YoungBlood said:
If it gets a little chilly up there in the winter, why not get one with a heating function too
We'll just close the windows and turn the PC's on lol. I think it does heat, when I looked at the demo unit someone had it on 30'c and warm air was coming out..? I put it down to 19'c and it was nice and cool - and dried out my gammy hand - so it seems like a good quality one

calnen, yeah it does work out a lot... but as pointed out, it doesn't always run off the full 2kw, and we'll be really careful using it (e.g., we'll only use it when we need it). It has a normal 'fan' function too - so we'll use the fan function and stick it onto 'cooler' when it gets muggy up here. We can always start paying the parents our share of the bill if it costs too much!

edit; haha, okay you've sold it to me - I'm getting a cool suit!

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#### calnen

Soldato
furnace said:
We'll just close the windows and turn the PC's on lol. I think it does heat, when I looked at the demo unit someone had it on 30'c and warm air was coming out..? I put it down to 19'c and it was nice and cool - and dried out the skin on my hand - so it seems like a good quality one

calnen, yeah it does work out a lot... but as pointed out, it doesn't always run off the full 2kw, and we'll be really careful using it (e.g., we'll only use it when we need it). It has a normal 'fan' function too - so we'll use the fan function and stick it onto 'cooler' when it gets muggy up here. We can always start paying the parents our share of the bill if it costs too much!

Just an alternative idea:
Rather than pump the heat out of the house, is there any way you could actually use it to heat downstairs?
Presumably you have central heating thats on a lot of the time, so if you just moved the hot air from the loft to the lounge (instead of pumping it outside and then heating downstairs as well) you'd kill two birds with one stone and maybe even save on your energy bill instead of add to it.
Just a thought. You could do it with a big tube going outside from the loft and back in downstairs somewhere (with a few fans pushing the air through), but it would be a bit of a DIY job...

I'm trying to think energy efficiency here

#### furnace

Soldato
calnen said:
OMG! Is that what the guy in the 'DONT WORRY, I'M FROM THE INTERNET!' pic is wearing?
A quick Google brings up this. I can't believe what some people actually do with their spare time

http://www.tronguy.net/TRONcostume/