To determine which size your WPU is, compare your model number to the table below. The first number(s) after "M-OD" refer to the nominal cooling capacity of your WPU in kW. This translates to the nameplate tonnage of your unit. For example, if your model # is "M.OD.13...", then your unit is a 3.5 Ton WPU (13 kW nominal cooling capacity).

AIRSYS WPU Model Number Nomenclature
| 1 | M-OD | Product series name: M-OD = MOBILECOOL-OUTDOOR: Packaged air conditioner with fresh air free cooling. | 
| 2 | 13 | Unit nominal total cooling capacity in kW | "3" = 1 Ton; "5" = 1.5 Ton; "7" = 2 Ton; "8" = 2.5 Ton (old style); "9" = 2.5 Ton; "13" = 3.5 Ton; "18" = 5 Ton | 
| 3 | E1 | Compressor type & qty: E1 = Hermetic scroll compressor qty 1; R1= Rotary compressor qty 1 | 
| 4 | C3 | Cabinet size code: There are 4 cabinet sizes: C1, C2, C3& C4. | 
| 5 | D | Control configuration: D = Unit is designed to operate in a Dual control environment (aka Lead/Lag operation) | 
| 6 | R410 | Refrigerant: R410 = R410a. | 
| 7 | 230/1/60 | AC Power source: 230/1/60 = 208/230V Single Phase 60Hz AC Power Source | 
| 8 | AC | Supply Fan configuration: DC = DC EC fan; AC = AC EC fan. (EC = Electronically commutated variable speed fan) | 
| 9 | 
 | Special code: Utilized to designate unit customization (non-standard configuration) | 
