Garage advice sought - heating and dehumidifier

[Dobie177]

So, its been a long time coming, but my garage build is almost complete... just one final decision regarding heating/ air-con/ dehumidifying to make.

The garage has been built with my Aston in mind - full cavity insulation, insulated garage door etc. - so it should avoid the worst of the winter cold, but I'm still keen to keep it warm and, importantly, keep the moisture to a minimum and avoid the conditions that cause corrosion/ paint bubbling.

I've done plenty of research but am still confused.

Earlier threads have recommended these kind of wall mounted units that heat, cool and act as dehumidifier... https://www.appliancesdirect.co.uk/p/iqool12/elect... - but is this like buying a washer/ dryer combo... never as good as individual units? And if the most important need is to dehumidify, I am compromising with this unit vs a standalone unit? And do I really need air-con - in the UK I can't see my garage getting that hot!

So, I'm leaning towards a wall hung heating/ cooling unit like this one (though am sure there are much cheaper units) - https://www.orionairsales.co.uk/panasonic-air-cond...

...with a dedicated a desiccant dehumidifier like this... https://www.dehumidifiersuk.com/eco-air-dd322fw-si...

Part of the reason I'm leaning this way is this advice...

"...desiccant absorption dehumidifiers should be used in garages, sheds and workshops as they work effectively in any temperatures whereas compressor units do not work well in cooler temperatures below 15 degrees C. Furthermore desiccant dehumidifiers have the ability to lower the Relative Humidity (RH) to 40%, or lower, which is below the rusting point of metal, which means that your car, motorbike, tools etc will be protected from rust."

I would hugely welcome all advice and experience...

Thanks
Dobie

[Dewi 2]

Ref.dehumidifiers.

I have used this one for several years.

https://www.meaco.com/dehumidifier/home-dehumidifi...

It is surprising just how much water is collected from an apparently dry garage.

There is a built in water collection tank, but instead of having the trouble of emptying that, a clear plastic hose (supplied) can be used to take water out of the garage. It is important that the hose is routed gradually downwards, to avoid an airlock (which turns off the dehumidifier).

Edited by Dewi 2 on Sunday 15th September 21:10

[V8V Pete]

Dobie177 said:

........... and, importantly, keep the moisture to a minimum and avoid the conditions that cause corrosion/ paint bubbling.

As far as I know paint bubbling on aluminium panels is caused by poor paint preparation and is not to do with atmospheric conditions. I don't want to put a downer on your garage and I am very envious of everyone who has a perfect place to keep their Aston but I think you could have the best dehumidified garage in the world and still get paint bubbling. The good news is that Aston seem to be taking a more sympathetic stance recently and are offering FOC repairs on cars well beyond 3 year manufacturers warranty.

[8Tech]

If the garage is reasonably well insulated, then a dehumidifier could do more damage than good. it is the opinion of some, more in the know than myself, that over drying the air can damage the leather and especially timber trim which can dry out and crack.

Unless you feed the leather and the wood trim, I would only use the dehumidifier if the garage was damp.

From an expert.......

"The aim is to arrive at a stable environment between 40% and 60% RH independent of outside temperature. Below 60% bare metal can be left out in the open and rust/corrosion all but stops. Below 40% RH leather and wood can dry too much and will become brittle and crack."

"By removing the moisture from the air in the garage with a car storage dehumidifier everything stored in the garage will remain condensation and corrosion free. Dehumidifiers are cheap to run, quiet in use and largely maintenance free. Suitably sized units will reduce and then maintain the humidity within the 40-60% RH target environment. In-built humidistats ensure that the air does not become too dry or too wet by turning the machines on and off as required. A correctly chosen dehumidifier will tolerate periodic changes of air such as opening the garage door or internal door. Furthermore, the action of dehumidification will bring the building as well as the contents into moisture equilibrium after a few weeks. If you then bring a wet car into the garage after a run in the rain it will actually dry it out for you!"

8Tech.

[singlecoil]

First thing to do is to find out what the relative humidity of your garage is at the moment. A simple hygrometer will tell you lots.

https://www.amazon.co.uk/ThermoPro-TP50-Digital-Th...

A well constructed building such as you have might only need a dehumidifier to be run occasionally and perhaps a quick go with a fan heater now and then.

[Johnnytheboy]

I have a compressor dehumidifier set quite gently so it's rarely running when I go in.

I had a dessicated one in the past and it was unreliable and short lived. They are better in cold weather, but the current one had only given up once in very cold weather in four years.

[Dobie177]

singlecoil said:

First thing to do is to find out what the relative humidity of your garage is at the moment. A simple hygrometer will tell you lots.

https://www.amazon.co.uk/ThermoPro-TP50-Digital-Th...

A well constructed building such as you have might only need a dehumidifier to be run occasionally and perhaps a quick go with a fan heater now and then.

Thanks - great advice. One now on order...

[Dobie177]

V8V Pete said:

Dobie177 said:

........... and, importantly, keep the moisture to a minimum and avoid the conditions that cause corrosion/ paint bubbling.

As far as I know paint bubbling on aluminium panels is caused by poor paint preparation and is not to do with atmospheric conditions. I don't want to put a downer on your garage and I am very envious of everyone who has a perfect place to keep their Aston but I think you could have the best dehumidified garage in the world and still get paint bubbling. The good news is that Aston seem to be taking a more sympathetic stance recently and are offering FOC repairs on cars well beyond 3 year manufacturers warranty.

Thanks Pete - I expect you're right!! Paint bubbling is the single biggest annoyance of owning a modern Aston - though all things in perspective and all that!!

Yes, I've noticed the more sympathetic stance also - and it's a huge relief and helps enormously in terms of good will. I wonder how much of that is APs direct influence?

[Dobie177]

8Tech said:

If the garage is reasonably well insulated, then a dehumidifier could do more damage than good. it is the opinion of some, more in the know than myself, that over drying the air can damage the leather and especially timber trim which can dry out and crack.

Unless you feed the leather and the wood trim, I would only use the dehumidifier if the garage was damp.

From an expert.......

"The aim is to arrive at a stable environment between 40% and 60% RH independent of outside temperature. Below 60% bare metal can be left out in the open and rust/corrosion all but stops. Below 40% RH leather and wood can dry too much and will become brittle and crack."

"By removing the moisture from the air in the garage with a car storage dehumidifier everything stored in the garage will remain condensation and corrosion free. Dehumidifiers are cheap to run, quiet in use and largely maintenance free. Suitably sized units will reduce and then maintain the humidity within the 40-60% RH target environment. In-built humidistats ensure that the air does not become too dry or too wet by turning the machines on and off as required. A correctly chosen dehumidifier will tolerate periodic changes of air such as opening the garage door or internal door. Furthermore, the action of dehumidification will bring the building as well as the contents into moisture equilibrium after a few weeks. If you then bring a wet car into the garage after a run in the rain it will actually dry it out for you!"

8Tech.

Thanks 8Tech. Given all the advice, I expect I'll settle on a simple wall heater for the colder days - and then a dehumidifier where you can set and maintain the 40-60% range you mention above (though I note that the exact % range changes depending on summer vs winter days). But, first port of call is the hygrometer which was suggested.

[Murph7355]

Dobie177 said:

Thanks Pete - I expect you're right!! Paint bubbling is the single biggest annoyance of owning a modern Aston - though all things in perspective and all that!!

Yes, I've noticed the more sympathetic stance also - and it's a huge relief and helps enormously in terms of good will. I wonder how much of that is APs direct influence?

They certainly weren't interested in sorting out their crap painting when I owned one It was the only thing I disliked about the whole experience.

A dehumidifier won't stop it on an Aston. But they're worth having anyway IMO. Just don't put them on too low a setting (60% is a good balance to stop seals and leather drying out but to keep the rest sorted).

Make sure you get one with a drain hose option as emptying them will likely be a regular occurrence.

I have a couple of Amber Dry units (Ruby dry is the same thing but a different case). These also work well at lower temps.