dehumidifier running costs

[Seeker]

I've been using a dessicant dehumidifier for a month and have just received my energy bill. My electricity usage is stable over the year so I know that it's cost me an extra £10 (plus the dehumidifier itself, obviously)

I've partitioned the garage using heavy plastic sheeting so that the dehumidified volume is roughly 3m x 1.5m x 2.5m (approx, the roof slopes). The dehumidifier is set to 60% rH.

It's a concrete garage and when first erected (during the heavy rains in Sept/Oct), the rH was in the 90 - 98% range. After coating the floor with PVA followed by a liquid DPM and then 2 coats of a 2 part polyurethane paint it dropped. Last week with the cold, sunny weather the rH was in the low 70s, today in the murky, misty weather it's 80%.

Why did I bother? Water would drip off the bikes because the humidity was so high and when I had a Triumph all the switches caused problems requiring them to be stripped and cleaned regularly. I tried using a fan pointing at the bike which helped to alleviate the problem a little but the Meaco works much better. I'm emptying the water tank every 36 hours or so - it does support a drain hose but I haven't got around to that yet.

[Nobbylad]

Would better airflow in the garage be cheaper and more effective?

[Seeker]

Originally Posted by Nobbylad

Would better airflow in the garage be cheaper and more effective?

cheaper? definitely.

more effective? no.

more cost effective? I can't really answer that since moving the air around with fans may have stopped water from condensing on the bike but the humidity was still present. As an example - my SV has had its header polished - with no fans running it would tarnish within 24 hours, with fans running and pointing at the header it would last 2 or 3 days, with the humidity lowered I stopped checking after a week.

I tried it (venting) with the previous garage which had a corrugated asbestos roof (so vents running full width), there were many areas where daylight was visible when looking up plus the door didn't seal well. It required fans to reduce the dampness and they had to be pointed towards the bike - a larger fan may have worked but I went with a dehumidifier instead.

[Adam Ef]

I have a friend who runs a dehumidifier in a flat and it has reduced his gas heating bills as apparently mositure in the air can make things colder (part of the reason the UK feels so cold when it's still above freezing, but places like the USA can be -10 degrees and not feel as cold). His electric bills are higher from running the dehumidifier but I think overall he saves a bit of money.

[DJ123]

the concrete is probably still releasing moisture and drying out. Since Sept/Oct it's not been warm enough to dry anything out that much - especially a large thermal mass of concrete. If/when we get a good hot summer that should help to release any trapped moisture and reduce the humidity.

Is your garage a part of the house/surrounded by other buildings that is causing it to be so much warmer inside, than the air outside?

[Seeker]

Originally Posted by DJ123

the concrete is probably still releasing moisture and drying out. Since Sept/Oct it's not been warm enough to dry anything out that much - especially a large thermal mass of concrete. If/when we get a good hot summer that should help to release any trapped moisture and reduce the humidity.

Is your garage a part of the house/surrounded by other buildings that is causing it to be so much warmer inside, than the air outside?

My garage is a new, standalone structure. When the garage was built I left the door open and ran a fan for a few weeks to aid with drying out the concrete and waited a few months before applying a liquid DPM. The previous 40 year old concrete garage was also prone to high humidity levels.

I only posted in case someone was considering using a dehumidifier, prior to getting one I was unsure of the running costs. I know that the compressor type are less expensive to run than the dessicant type (which contain a heater to re-dry the chemicals). When researching I discovered that compressor dehumidifiers don't work well in low temperatures (below 5°C). Humidity climbs at night and temperature drops so the dessicant type was better suited for my application since the garage is unheated.

I live less than 1 mile from the Humber estuary - it's going to be humid.

[Nobbylad]

I live in a semi-rural area, prone to fog etc and about 5 miles as the crow flies from the Mersey Estuary/Irish Sea.

The garage is attached to the house, has no ceiling and is not airtight. Never noticed any condensation, but do get the odd bit of water under the garage door when the rain drives hard at it.

[shiftin_gear98]

Life is too short, Take it out of it's cocoon and just ride the sodding thing.
Then like mine, it'll be caked in **** 99% of it's life and you'll stop caring. But have fun on it.

I really must clean my bike this weekend, so I can, A cut my hand on something. B let it get filthy again by the time I get to work on Monday.

[garynortheast]

Originally Posted by shiftin_gear98

Live is too short, Take it out of it's cocoon and just ride the sodding thing.
Then like mine, it'll be caked in **** 99% of it's life and you'll stop caring. But have fun on it.

Wot Martin sez!

[Dave20046]

Originally Posted by Seeker

I've been using a dessicant dehumidifier for a month and have just received my energy bill. My electricity usage is stable over the year so I know that it's cost me an extra £10 (plus the dehumidifier itself, obviously)

I've partitioned the garage using heavy plastic sheeting so that the dehumidified volume is roughly 3m x 1.5m x 2.5m (approx, the roof slopes). The dehumidifier is set to 60% rH.

It's a concrete garage and when first erected (during the heavy rains in Sept/Oct), the rH was in the 90 - 98% range. After coating the floor with PVA followed by a liquid DPM and then 2 coats of a 2 part polyurethane paint it dropped. Last week with the cold, sunny weather the rH was in the low 70s, today in the murky, misty weather it's 80%.

Why did I bother? Water would drip off the bikes because the humidity was so high and when I had a Triumph all the switches caused problems requiring them to be stripped and cleaned regularly. I tried using a fan pointing at the bike which helped to alleviate the problem a little but the Meaco works much better. I'm emptying the water tank every 36 hours or so - it does support a drain hose but I haven't got around to that yet.

Have you identified the cause of the damp? And have you added ventilation if there isn't already any?
Insulative board might help to stop the temperature changes being so drastic and keepo the condensation off, but if there's so much moisture present it sounds like the problem will continue...and that will also be an expense.

edit, just seen the above has been addressed - I'd add air bricks, you need air circulation. Or continue with the humidifier until the concrete dries out. I take it they put a physical moisture barrier under the concrete?