Ventilating an insulated shed

[leedm]

Hi,

I have recently had an 8' x 3' shed built to accomodate aquarium filtration equipment and a sump tank. The sump tank is housing approximately 150 litres of water at 25 degrees C.

The shed has been fully insulated with 50mm Kingspan.

I have a indoor/outdoor temparature and humidity monitor and it is showing my relative humidity as 99%. Therefore, I need some help getting this down.

At the moment, I have one vent down low on the shed door which was installed by the person who built the shed for me.

Today, I added a 2nd vent to the top of the same door with the idea that this would remove the warmer moist air.

I have installed the vent grills on the outside of the door.

Few things I'm not sure on

1. Is it correct to install the vent grill on the outside, or should it be on the inside of the shed ?
2. Would it be better to have other vents on other walls of the shed, rather than having them on the same wall ? I can only realistically install another vent on the opposite wall

3. Is there a way of working out how much ventilation I need other than trial and error ?

Any other suggestions to help deal with the humidity would be greatly appreciated

Thanks

Lee

 

[Blagard]

Installing the external vent grill is more important as this has a weathering function on the opening. The inside ones are really only to tidy up the appearance so optional on a shed! - That is unless you use a "hit and miss vent" inside that allows you to vary the amount of air passing through it. You might find that a useful tool in getting it right

Cross ventilation is usually the best solution, low vent one side, high vent on the other. This helps move all the sheds air through rather than for instance venting one corner with air going out almost as soon as it comes in.

You could vent the ridge but this might prove to be too efficient and you would lose a lot of heat quickly.

For a space relying on natural ventilation trial and error is about all you can do. Fans are used when specific volumes of air need to be moved and I think that is overkill on a shed.

Edit: without cross ventilation a small oscillating fan, like a desk fan, to stir the air up and prevent stale areas might help, for instance if your vents are on one wall only