Thanks Eddie but I intend to keep it heated along with the house timer which tends to come on for a coupe of hours in the morning and a few hours in the evening in winter, unless of course it is very cold in which case it is on for longer.
Obviously I can regulate the individual radiators in the garage via the attached thermostats.
I have been using a dehumidifier for a few years in my old garage so if what Steve says is correct I will continue to use it.
The only problem with a dehumidifier is that if the garage is not pretty well sealed you end up dehumidifying the neighbourhood!