This is often an electrical heater. When the outside air gets to all around 6*c (42.8F) the heater will occur on and warmth the air up to shield the factors inside from frost. Otherwise This might freeze the heating and cooling coils within and burst them. AHUs casing is generally https://air-cooled-chillers87653.bloggadores.com/31746566/the-best-side-of-ahu-s