Make up air system

In an industrial system associated with a building and utilizing a process in which the temperature of a cooling fluid is increased in the process and the fluid is recirculated and is cooled to be reused in the process and in which make up air is to be brought into the building at a selected temperature, apparatus for cooling the fluid and for providing heated make up air to the building comprising:

• tube means including cooling tubes located outside the building and circulating the fluid to be cooled, first and second input chambers located on one side of said cooling tubes and adapted to direct air towards said cooling tubes, a fan located in each of said input chambers and being selectively operable for forcing air from the atmosphere over said cooling tubes whereby the fluid is cooled and the temperature of the cooling air is raised, first and second output chambers located on the opposite side of said cooling tubes with said first and second output chambers being associated with said first and second input chambers, respectively, whereby said output chambers receive the heated air after it is forced over said cooling tubes, said first output chamber having a first opening connected with the building and being operable for directing heated make up air from said first output chamber into the building, said second output chamber having a second opening operable for directing the heated air to the atmosphere, control means operatively connected with each of said fan for separately actuating the same in response to the fluid temperature of the fluid being cooled whereby the fluid will be cooled to a desired temperature, said control means operatively connected with said first output chamber and with said fan associated with said first input chamber and being responsive to the temperature of the fluid being cooled for controllably varying the amount of heated make up air directed into the building as a function of the temperature of the fluid being cooled.