This is frequently an electrical heater. When the outside air receives to around six*c (forty two.8F) the heater will arrive on and heat the air up to shield the components inside of from frost. If not This might freeze the heating and cooling coils inside and burst them. Many typical https://industrialchillerhire88876.blogofchange.com/35006975/5-simple-techniques-for-air-handling-units-ahus