I have successfully fogged every pair of goggles I have owned, even on cold days. This pair has proved that while they still fog a little when the fan is off, a chair lift ride with the fan on generally removes the fog, and skiing with it on low usually prevents the fog from forming in the first place. Calling the fan "silent", especially when wearing a helmet is a bit of a stretch, but I will admit I prefer to see and occasionally have the noise, than to not see at all. Only downside I have seen is that the lens does a weird tinting thing when there are two different temperatures applied. Once it clears they are fine, but until it does it makes seeing very difficult, again I'll live with it. The form factor of the newer generations is vastly improved over the old ones too, no more monster goggles.