TRG-TRC001-EN 19
period two
Air Mixtures
notes

If outdoor air B is mixed with recirculated air A, the conditions of the resulting

mixture are found somewhere on a straight line connecting the two points.

If the mixture is half and half, this condition falls on the midpoint of the line

between A and B. If more than half of the mixture is recirculated air A, the

condition of the mixture will fall closer to A than to B.

In this example, 1,000 cfm of outdoor air (OA) is mixed with 3,000 cfm of

recirculated air (RA) for a total supply airflow of 4,000 cfm.

First, the percentage of outdoor air within the mixture is determined. This is

done by dividing the outdoor air quantity by the total air quantity.

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