how does a conduction freezer change electric current into cold air ?

the freezer in question has no fan only a system of "pipes that form frost on their surface. I was wondering if the "pipes" or metal tubing contained a liquid. if so what liquid?

What type of freezer? Does it make noise or is it silent?

If it makes noise/has a compressor, It uses a gas compressed then cooled using ambient air, The gas then passes through an expansion valve which turns it into a very cold liquid (I think it's a liquid). It then repeats the cycle. (More info on that see here)

If it is virtually silent it is Thermoelectric cooling, Thermoelectric cooling uses the Peltier effect to create a heat flux between the junction of two different types of materials. This effect is commonly used in camping and portable coolers and for cooling electronic components and small instruments. (see more here)