열손실은 폐수로부터 잃은 열량과 청수로부 터 얻은 열량간의 차이인 열손실 에너지(열량)는 식 (4)에 나타냈다.
Heat loss is indicated in formula (4) by the heat loss energy (heat amount), which is the difference between the amount of heat lost from wastewater and the amount of heat obtained from the clean water.