Application Data (continued)
For VAV applications, the YORK eco2 unit uses a VFD to modulate fan speed and maintain a constant duct static pressure. VFDs offer superior control over the operation of the unit at part load, and offer the addi- tional benefits of quieter and more efficient operation when compared to IGV.
HARSH ENVIRONMENTS – CONDENSER AND EVAPORATOR COIL PROTECTION
For harsh environmental conditions such as seashore applications, YORK offers three types of coil protec- tion: copper fin material, black fin and Technicoat coat- ings. YORK recommends that for corrosive environ- ments that copper fins be used to protect the evapora- tor and/or condenser coils. In areas where chemicals that can corrode copper are present, such as ammo- nia, YORK recommends that the black fin or Technicoat coating be used for maximum protection.
Copper Fin Condenser Coil
Copper fins can be used instead of aluminum for addi- tional corrosion protection, however it is not suitable for areas that are subject to acid rain or exposed to ammonia.
Pre-Coated Condenser Fins
Black fin coating (yellow fin for evaporator fins) is pre- coated application epoxy on aluminum fin stock to guard from corrosive agents and insulate against galvanic po- tential. It is used for mild seashore or industrial loca- tions. This can provide corrosion resistance comparable to copper fin coils in typical seashore locations.
Post-Coated Condenser Fins
Technicoat (a
Any of the above suitable options should be selected based on the particular project design parameters and related environmental factors. The application should be further reviewed and approved by the consulting en- gineer or owner based on their knowledge of the job site conditions.
BUILDING EXHAUST SYSTEMS
Building exhaust systems are often necessary when economizers are used to bring in outdoor air. Without proper building exhaust, the building may become over- pressurized. The exhaust system maintains the proper building pressure by expelling the appropriate amount of air from the building. Exhaust systems are typically designed to exhaust approximately 10% less air than what is entering the building. This provides a slight posi- tive pressure on the building.
100% modulating exhaust with building static pressure sensing and control
The 100% exhaust system can be configured with ei- ther control actuated dampers or VFDs for modulating control. The unit controller monitors the building pres- sure using a differential pressure transducer and main- tains the required building static pressure by modulat- ing the exhaust control. If the building has other means of exhaust or building pressure is not important, on/off or barometric control may be used.
100% modulating exhaust with fan on/off control
The 100% exhaust system can be configured for on/off operation eliminating the expense of the damper ac- tuators or VFDs. This exhaust system can be controlled by either the outside air damper position, or a building static pressure sensor.
Barometric exhaust
Barometric exhaust can be used when smaller amounts of air at low static pressure variations within the build- ing or other means of building exhaust are employed. Barometric exhaust is commonly used where there are only small fluctuations in building pressure or where building static pressure control is not necessary.
ROOF CURB
Optional
10 | YORK INTERNATIONAL |
