This is frequently an electrical heater. When the outside air will get to about six*c (42.8F) the heater will arrive on and warmth the air up to safeguard the components within from frost. Otherwise This might freeze the heating and cooling coils inside of and burst them. The ACR 160kw https://industrialboilerrental60482.imblogs.net/81983431/a-simple-key-for-air-handling-unit-ahu-hire-unveiled