"Furnaces are used for the purpose of heating homes and for that it is important that a correctly sized furnace is installed in a home for ultimate comfort. However, many a times it is seen that HVAC contractors try to sell of an oversized furnace just for the sake of money and the result are too many problems cropping from it.Some of the common problems associated with big sized furnaces are the following:A furnace that is oversized cycles on and off frequently. This is because the set temperature is reached within a very short time and then the furnace shuts off and again starts after some time. This causes unnecessary wear and tear of the heating unit causing an overall reduction in its life span.Similarly, an oversized furnace makes the operation of the furnace inefficient because the set temperature is reached before the unit starts operating at its peak efficiency and the result is the furnace shuts off because the thermostat is already satisfied. This happens repeatedly. The result is wastage of energy.To feel uncomfortable is another problem of a bigger furnace because too much conditioned air is circulated within a room at once and as a result one might feel too warm within the room causing major temperature swings.Lastly, an oversized furnace might cause high energy bills and additional installation cost. Hence, in order to avoid these problems it is imperative to install a correctly sized furnace."