The weather is changing on an almost daily basis with rare high temperatures of 14 degrees here yesterday dropping to 5 or 6 degrees at night. These swings not only make us uncomfortable but create the challenging conditions for cars kept outside under covers, namely condensation.
Definition - Condensation is the process by which water vapour in the air is changed into liquid water.
Noun - water which collects as droplets on a cold surface when humid air is in contact with it.
Sometimes more often in springtime it is described as dew which commonly forms in the morning on leaves and grass when the warmer air deposits water molecules on the cool leaves.
Why do I get condensation on my car under a cover?
Whether we describe it as condensation or dew, drops in temperature overnight cause water to be left on cars in the early morning even under a cover. This is because our covers are breathable and so air is present beneath the covers and when the air temperature drops to the dew point it becomes saturated and some water from the air will condense. The dew point is a measure of humidity or how much water vapour the air contains at any given time. Warmer air holds more water than cooler air and so when the air temperature drops to the dew point condensation is created.
What can I do about it?
This is nothing to worry about, the breathability of the covers will allow the water to evaporate (the reverse process of condensation) once the air warms up. At times you may also see some ‘blooming’ on the car, again this is nothing to cause concern it is simply the water on the car before it has had a chance to fully evaporate. As ever the most important element is that the cover is breathable.
Any car that is kept outside will from time to time depending on the weather experience condensation or dew formation. Providing the water can evaporate through the cover this will not cause any problems.
Important difference between winter and spring
Here lies the complication. In spring we expect the air temperatures to rise high enough most days to allow any water on the car under the cover to evaporate. During winter when particularly at the moment the weather is erratic if the temperatures do not rise, we recommend lifting the cover from the car to allow any trapped moisture to escape before recovering the car.
Does this mean I should not use my cover in winter?
No absolutely not! We use the covers ourselves in winter and that is what they are designed for, but at times the covers need a little extra help to perform their best. If temperatures are consistently cold then there is nothing to worry about, that said we do recommend that all covers are lifted at least once a month.
Please note - at certain times of year (particularly in winter) when the air temperature fluctuates often, you will find that any outdoor car cover won't stop condensation forming on the car. The cold bodywork of the car will attract condensation due to the warm microclimate within the car cover, however these covers are fully breathable, so as the temperature equalises this will evaporate through the cover. If you are worried about condensation forming during this higher humidity weather, we advise removing the car cover for a short while to let both the cover and the car air.