Using a dehumidifier in a garage.

Using a dehumidifier in a garage.

Author
Discussion

A900ss

Original Poster:

3,245 posts

151 months

Sunday 11th January 2015
quotequote all
Hi,

I've finally got the use of my own garage after the wife has emptied her crap into a shed. This now means my car can spend its time stored in a nice garage over the winter.

It only went in the garage yesterday and as it's been out in the elements all winter, the dehumidifier I have put in there is working overtime and drawing loads of moisture out of the air. I hope this will slow down as the car fully dries and would like to know from others that use dehumidifiers, how long they tend to run them for every day/week?

Thanks.

PS - garage is fairly well sealed and its a desiccant dehumidifier.

Edited by A900ss on Sunday 11th January 17:40

FurtiveFreddy

8,577 posts

236 months

Sunday 11th January 2015
quotequote all
When the weather is like it is at the moment I have to run mine 24 hours a day to keep the RH in the 60's. It's got an auto setting so it's not on full blast all the time, but I'd rather pay the electricity bill than watch everything in there corrode as I use it as a bit of a workshop and storage area as well.

I've tried to seal the doors and windows as best as possible but I'd need to spend a lot more time and money doing it to make it properly airtight.

Motown Junk

2,041 posts

216 months

Sunday 11th January 2015
quotequote all
Mine took quite a few days to dry out the walls as well as the car,emptying the inbuilt reservoir probably twice a day at first. Now plumbed into a drain outside and just leave it on low 24/7, if it's dry enough just stays in fan mode to circulate.

Recommend getting a cheap humidity meter of ebay to see the difference the dehumidifier makes.

PaulJ37

121 posts

131 months

Sunday 11th January 2015
quotequote all
What a great idea - I had never even considered using a dehumidifier in the garage. How much do they cost?

I remember having one in my horribly damp flat a few years ago.

kambites

67,462 posts

220 months

Sunday 11th January 2015
quotequote all
I run mine set to 40% humidity and, now it's largley dried everything out, it runs maybe two or three hours a day.

James19181

237 posts

111 months

Sunday 11th January 2015
quotequote all
PaulJ37 said:
What a great idea - I had never even considered using a dehumidifier in the garage. How much do they cost?

I remember having one in my horribly damp flat a few years ago.
We have an ecoair dd122 to sort out damp in our house, £130 on amazon

Works well, expect it'd do a garage fine

Johnnytheboy

24,498 posts

185 months

Sunday 11th January 2015
quotequote all
I just leave both mine running on low.

The old one I have in my garage at home has a tank, and I really notice it increase its capture rate when the weather is damp.

benny 61

467 posts

183 months

Sunday 11th January 2015
quotequote all
I have three settings on mine and if I keep it on the lowest setting its just right. I too have a drain hose fitted to save emptying it regularly so I'm not sure how much moisture it removes. Great things.

BIRMA

3,803 posts

193 months

Sunday 11th January 2015
quotequote all
You really need to insulate the garage if it's a single skin building plus if the garage door is just a single skin you will waste a lot of energy particularly if you have a desiccant de-humidifier.
I bought a load of 12.5 mm Celotex 8x4 sheets covered the walls and ceiling then went about filling my double garage door with polystyrene which I glued to the single skin then fixed the Celotex boarding to it. I fixed some polycarbonate sheeting over the window and door which helped privacy.
The result is that my refrigerant type de-humidifier which by the way is a bit dearer to buy than the desiccant but about 1/5th the cost to run keeps my motorbikes and my car at about 55 RH from November to April.
The foil face of the Celotex reflects light so it's a lot brighter and a nicer in the workshop for working in. I have a unit that monitors all temps and humidity and for the last four years the RH has never been greater than 65% with this set-up plus the running costs are minimal. Check out the desiccant consumption it will scare you I had one for one winter then threw it away as the refrigerant type was about 1/5th the running costs.

Edited by BIRMA on Monday 12th January 13:51


Edited by BIRMA on Monday 12th January 13:51

jonny_bravo

533 posts

222 months

Sunday 11th January 2015
quotequote all
BIRMA said:
You really need to insulate the garage if it's a single skin building plus if the garage door is just a single skin you will waste a lot of energy particularly if you have a desiccant de-humidifier.
I bought a load of 12.5 mm Celotex 8x4 sheets covered the walls and ceiling then went about filling my double garage door with polystyrene which I glued to the single skin then fixed the Celotex boarding to it. I fixed some polycarbonate sheeting over the window and door which helped privacy.
The result is that my refrigerant type de-humidifier which by the way is a bit dearer to buy than the desiccant but about 1/5th the cost to run keeps my motorbikes and my car at about 55 RH from November to April.
The foil face of the Celotex relicts light so it's a lot brighter and a nicer in the workshop for working in. I have a unit that monitors all temps and humidity and for the last four years the RH has never been greater than 65% with this set-up plus the running costs are minimal. Check out the desiccant consumption it will scare you I had one for one winter then threw it away as the refrigerant type was about 1/5th the running costs.
+1
The first year I ran my dehumidifier in my concrete sectional garage it was running a lot!

Battening the walls , putting a damp membrane on the walls and an inch of kingspan had made a huge difference. I was in the garage this afternoon and the dehumidifier didn't cut in once in maybe 4 hrs.

FurtiveFreddy

8,577 posts

236 months

Sunday 11th January 2015
quotequote all
BIRMA said:
You really need to insulate the garage if it's a single skin building plus if the garage door is just a single skin you will waste a lot of energy particularly if you have a desiccant de-humidifier.
I bought a load of 12.5 mm Celotex 8x4 sheets covered the walls and ceiling then went about filling my double garage door with polystyrene which I glued to the single skin then fixed the Celotex boarding to it. I fixed some polycarbonate sheeting over the window and door which helped privacy.
The result is that my refrigerant type de-humidifier which by the way is a bit dearer to buy than the desiccant but about 1/5th the cost to run keeps my motorbikes and my car at about 55 RH from November to April.
The foil face of the Celotex relicts light so it's a lot brighter and a nicer in the workshop for working in. I have a unit that monitors all temps and humidity and for the last four years the RH has never been greater than 65% with this set-up plus the running costs are minimal. Check out the desiccant consumption it will scare you I had one for one winter then threw it away as the refrigerant type was about 1/5th the running costs.
My understanding was that a compressor type of dehumidifier isn't as efficient to use at low temperatures, so if your garage isn't heated and gets below 2-3 degrees in winter, as mine does then you're better off using a desiccant type.

Interested to hear opinions on this though.

jonny_bravo

533 posts

222 months

Sunday 11th January 2015
quotequote all
Yes, absolutely need a dessicant. They function at far lower temps than the traditional compressor units.

kambites

67,462 posts

220 months

Sunday 11th January 2015
quotequote all
jonny_bravo said:
Yes, absolutely need a dessicant. They function at far lower temps than the traditional compressor units.
If the garage isn't heated, yes. My condensing dehumidifier isn't very effective below about 10 degrees celsius and simply doens't work at all below about 3 because the condensor freezes. The flip side is that a cheap dessicant dehumidifier will struggle to remove enough moisture in humid weather above about 20 degrees celsius. The cheapest way to keep an unheated garage dehumidifed all year 'round would probably be to have both.

Fortunatley my garage has a room above it so rarely drops below about 10 celsius.

Edited by kambites on Sunday 11th January 19:26

BIRMA

3,803 posts

193 months

Sunday 11th January 2015
quotequote all
Sorry forgot to mention I have an Economy 7 storage heater(separate spur) to maintain a decent background source of heat. Although at first I thought it would be expensive I just keep it low and it remains warm all day plus with very little heat loss now I've sealed most of the gaps it keeps everything nice. The temperature has never fallen below 10c in four years.

Edited by BIRMA on Monday 12th January 12:20

Stephen-ro9kw

8 posts

100 months

Friday 12th February 2016
quotequote all
I have kept my car in garage for long time. It was immaculate JDM import with like new condition inside out.
However, last year when I took the photos of underneaths and compare to 8 years ago, more area are found with rust such as steering rod nut, catalyst converter shield and exhaust related bare metal.

My garage is double garage with single brick wall.
I have changed the side door to the new one with very tight seal.
I bought weatherstop top and floor seal for both garage doors.
There are some small/tiny area where garage door hinge's design where the air flow can happen.
The back#s air vent also allow air flow.

I have bought EcoAir DD322FW Simple and connect the hose from it to drain to outside.
I have never done any insulation. No heating system is present in double garage.
I have followed the supplier's advice to switch on Turbo mode, and run for couple days to a week.
The digital meter has shown I have about 10% or more drop in humidity level.

In last 7 days (cold weather), Inside the garage, the maximum I have seen is 77-78% before I use dehumidifier, now the lowest I can see is 62% in UK South (Oxfordshire area). I cannot make/control the RH dropping to 45-60%. Very frustrated, and believe the rust still can happen.

Called the supplier, they said I better seal everything and make the garage heated. Be honest, if I can do it, I don't really need a quick solution of dehumidifier.

Can anyone of you give me some advice and what's view toward my situation here? Many Thanks!

SpeckledJim

31,608 posts

252 months

Friday 12th February 2016
quotequote all
Easier to get a cheap carcoon to put the dehumidifier inside than try to seal the whole garage surely?

You'd only have to open the garage door for 30 seconds to completely recycle the dry air for a fresh load of damp air?


DaveCWK

1,979 posts

173 months

Friday 12th February 2016
quotequote all
Isn't the easiest way to keep a garage dry to improve ventilation? Why not install an extractor fan on the back wall. Air drawn from under garage door, over car, out back.

Stephen-ro9kw

8 posts

100 months

Friday 12th February 2016
quotequote all
I thought about carcoon/car capsule solution, but it is not convenient when I work on the car. Also, I may have 2nd car in the double garage soon, so two carcoon is costly solution.

Extracted Fan with duct is probably my next option.

Have anyone experienced similar situation? I did check all neighbors' garage, we are pretty much the same, I don't see my double garage has any special wrong. Just wonder whether 60-65% RH is treated as high or average in South UK during winter like now?

FurtiveFreddy

8,577 posts

236 months

Friday 12th February 2016
quotequote all
Without my dehumidifier running, I've seen RH up to 90% in my garage (single brick walls, no insulation).
The dehumidifier I currently use (Meaco 8L) is run 24/7 on the laundry mode and that brings it down to 45-55% most of the time and it turns itself off when it gets to 45% anyway, to save power.

I think 45-50% RH is fine. The heat it puts out keeps the garage couple of degrees above outside air temperature, so that helps too.

You don't need to reduce RH to zero and it would be quite difficult to get it below 30% in most brick-built detached garages with the current weather anyway unless you used an industrial dehumidifier.

Rust occurs when certain conditions are present but humidity isn't necessarily the biggest factor.

Recently, I had to clear out a garage where a car had been stored for almost 30 years. There was literally no rust on any exposed metal and a couple of small rusty patches which were present when the car had been originally stored, hadn't got any bigger.

The garage was on it's own at the bottom of the garden, with no heating or electricity. There were holes in the roof and side door, so there was a degree of ventilation.

My theory is that because it was constructed of thin concrete panels instead of brick, the moisture wasn't being trapped in the walls and there was no chance of any condensation inside, so although the car would have sat in cold, damp conditions when it was raining, the ventilation and absence of trapped moisture prevented rust from forming.

It also wasn't situated anywhere near the sea, which is another thing to consider if you live near the coast.

BIRMA

3,803 posts

193 months

Friday 12th February 2016
quotequote all
If you can keep the garage at 50-60% RH cars and bikes should be fine. I have weather monitors around my house with a remote unit in my garage, on a typical rainy day my unit outside registers 90% plus RH so if the air around the garage is that damp/wet any air that enters the garage will surely have a very high RH factor.