Working out costs to run a dehumidifier?

[Chris Wilson]

Should be able to work this out myself, but I can't / am lazy / thick, whatever

 

I am getting condensation in my car transporter truck, after frosty or very cold nights the single skin translucent fibreglass roof drips. It definitely isn't leaking, it's condensation as the temps outside and in diverge. I may put a second skin inside the roof, with insulation, but then I lose nearly all natural light in the box of the truck, and would probably have fit expensive internal lighting. For now I have pilfered the dehumidifier out of the house and put it on fast fan, on a modest humidity setting, in the truck's box. If I guesstimate it's on say 6 hours in 24 what figures do I need to work out the running costs?

 

Cheers.

[JamesG]

Find out the wattage of the dehumidifier and find out from your electricity bill how much you pay per kWhour.

 

If it uses 1000W and you run it for 6 hours, then it's used 6 kWhours.

[Chewie]

The easy way would be to measure the current drawn by the fan motor and the pump then work out the power used over the 6 hrs you intend to operate it. Or just have a peep at the lecky meter when it's on.

[Meko]

744 hours in a 31 day month so a quarter of that (6 out of every 24) is 186 hours

 

turn the wattage into KW - 100watts = 0.1kw

 

kw * hours = x

tarrif = y

 

cost per month = x * y

then divide that by 31 to get the cost per day.

 

 

so...

 

250watt dehumidifier = .25KW

 

.25 * 186 = 45.5KW used per month.

 

13.5p (roughly) per KW * 45.5kw = 614.25p or £6.14 per month / 19p a day.

 

 

i think.

[Chewie]

Find out the wattage of the dehumidifier and find out from your electricity bill how much you pay per kWhour.

 

If it uses 1000W and you run it for 6 hours, then it's used 6 kWhours.

 

Whoah. Not necessarily so. That would be it's max power rating and not the power it would use. A dehumidifier's work load would depend on the ambient temperature and the amount of water in the air. These wouldn't be constants and would actually vary during the day and the weather conditions.

[JamesG]

Whoah. Not necessarily so. That would be it's max power rating and not the power it would use. A dehumidifier's work load would depend on the ambient temperature and the amount of water in the air. These wouldn't be constants and would actually vary during the day and the weather conditions.

 

Good point. Although I didn't actually say find out the wattage by reading the label

[Meko]

Whoah. Not necessarily so. That would be it's max power rating and not the power it would use. A dehumidifier's work load would depend on the ambient temperature and the amount of water in the air. These wouldn't be constants and would actually vary during the day and the weather conditions.

 

 

but using it's max wattage, would give you the most you're likely to pay.

[Chris Wilson]

Worst case scenario is fine It cycles like a fridge in reverse, so it's current draw presumably changes? I'll have a look at its rating plate tomorrow. I sometimes think they can be optimistic to make you think they're cheaper to run, what do you need to actually measure AC 240 volt current draw?

[Chewie]

but using it's max wattage, would give you the most you're likely to pay.

 

Do you drive your Supe 24/7 on full throttle and it giving you 10 mpg and budgeting for that? Or getting the worst insurance quote and not bothering with a cheaper deal because it's the most you're likely to pay? Nope I doubt it.

[Chewie]

Worst case scenario is fine It cycles like a fridge in reverse, so it's current draw presumably changes? I'll have a look at its rating plate tomorrow. I sometimes think they can be optimistic to make you think they're cheaper to run, what do you need to actually measure AC 240 volt current draw?

 

You could plug in a multimeter but easiest is to note the kWhr used on your domestic lecky meter over say 1/2 hr. Make sure everything else is switched off. Simples!

[Meko]

Do you drive your Supe 24/7 on full throttle and it giving you 10 mpg and budgeting for that? Or getting the worst insurance quote and not bothering with a cheaper deal because it's the most you're likely to pay? Nope I doubt it.

 

there's a bit of a difference.

When you're trying to work out how much it'll cost you to run a dehumidifier for a few days / weeks and the maximum it'll cost is acceptable then you know it's the worst case scenario and it won't impact your bill that much.

You can't work out how much it's going to cost to run with it being up and down and all over the place. If you don't mind paying a tenner a month for it, and the maximum it's going to cost is less than that, then you're not losing anything.

[Meko]

You could plug in a multimeter but easiest is to note the kWhr used on your domestic lecky meter over say 1/2 hr. Make sure everything else is switched off. Simples!

 

 

 

but that's still going to change depending on the ambient temperature and amount of water in the air.

 

Whoah. Not necessarily so. That would be it's max power rating and not the power it would use. A dehumidifier's work load would depend on the ambient temperature and the amount of water in the air. These wouldn't be constants and would actually vary during the day and the weather conditions.

[Chris Wilson]

Ah, that reminds me, the electric board came and fitted a new digital meter the other month, I must have a look at it, and see how the display works. I have found a few sites that give makers suggested cost per hour for various models, ranging from 3 pence to over 70 pence.