Why some appliances producemoreheatthan others?

This depends specifically on the appliance and the way it is designed. For instance dryers, dishwashers, etc. are designed to produce heat and the heat given off is not necessarily a sign of energy loss or inefficiency. Also, appliances like refrigerators are not only designed to cool the inside, but also to take the warm air out of the food compartment, this is why you bottom vent on a fridge will often produce a warm breeze. The heat produced by appliances differed on design and efficiently its built. Remember! heat is only another form of energy and electrical energy turns into heat in objects like Transformers, which are in appliances, and when this happens its energy loss. Appliances labeled as Energy Star are designed to eliminate energy loss and maximize efficiency which is also why Energy Star appliances may run cooler then typical appliances.