A manufacturing needs to put a glass window in an oven. To make sure the safety of the household, the oven window must never have a temperature of more than 50 degree C. To clean the oven, a temperature of 225 degree C is used. Compute the air hap (K=0.0242W/mK) between two sheets of 5 mm glass (K=0.84W/mK). The convective heat transfer coefficient on both sides of the glass is 6W/m square K.