Product data

I Determine job requirements.

Given:

Room Sensible Cooling Load . . . . . . . .8,200 Btuh

Room Total Cooling Load . . . . . . . . .11,000 Btuh

Entering-Air Temperature . . . . . . 80 F at 50% RH

Entering Water Temperature . . . . . . . . . . . . .45 F

Temperature Rise . . . . . . . . . . . . . . . . . . . . .10 F

Nominal Air Delivery . . . . . . . . . . . . . . . . 350 cfm

II Determine unit size and nominal cfm.

For an initial selection, choose a unit size that will

provide the required airflow (cfm). Refer to the

Physical Data table on page 3. At high speed, a

42WKN12 unit will provide 350 cfm.

III Determine total cooling capacity.

Refer to the cooling capacity table for 42WKN12

on page 10. Locate required entering dry bulb (edb)

and relative humidity (RH) conditions. Locate the

entering water temperature required. Under Total

Cooling (TC) column, a 42WKN12 unit at an enter-

ing-air temperature of 80 F dry bulb at 50% RH, an

entering water temperature of 45 F, and a water

temperature rise of 10 F, will provide 11,236 Btuh.

IV Determine sensible cooling capacity.

In cooling capacity table for 42WKN12, locate the

sensible cooling (SC) column and find that the

42WKN12 at the required conditions will provide

8,200 Btuh of sensible cooling at a water tempera-

ture rise of 10 F. The 42WKN12 will satisfy the job

requirements.

If additional SC were required, a larger unit or a

lower entering water temperature would be needed.

Selection procedure (42WKN12 unit example)