Catalogue

WSHP-PRC020D-EN 41
Unit Fan Performance
Example 1 (Ethylene Glycol): The antifreeze solution is 20% by volume of Ethylene Glycol.
Determine the corrected cooling capacity and waterside pressure drop for a GET009 when the EWT
is 86°F and the GPM is 2.3.
From the catalog data, the cooling capacity at these conditions with 100% water is 8.3 Mbtuh, and
the waterside pressure drop is 9.1 feet of head. At 20% Ethylene Glycol, the correction factor for
cool capacity is 0.9912 and the pressure drop is 1.068.
The corrected cooling capacity (Mbtuh) = 8.50* 0.9912 = 8.43.The corrected water side pressure
drop (Ft. head) = 9.1 * 1.068 = 9.72.
Example 2 (Propylene Glycol): The antifreeze solution is 30% by volume of Propylene Glycol.
Determine the corrected heating capacity and waterside pressure drop for a GET009 when the EWT
is 45°F and the GPM is 2.3.
From the catalog data, the heating capacity at these conditions with 100% water is 8.3 Mbtuh, and
the waterside pressure drop is 11.1 feet of head. At 30% Propylene Glycol, the correction factor for
heat capacity is 0.9603 and the pressure drop is 1.174.
The corrected heating capacity (Mbtuh) = 8.3 * 0.9603 = 7.97.The corrected water side pressure drop
(Ft. head) = 11.1 * 1.174 = 13.03.
Figure 6. Cooling capacity correction factor
Figure 7. Heating capacity correction factor
Figure 8. Water pressure drop correction factor