Specified Applications

Ventilation Technical Information Link

Every application poses a new challenge to the specifying engineer. Diverse climates, fresh air requirements, system control needs and installation limitations mandate a wide range of climate control solutions. Bard provides these solutions through a diverse line of features and options specifically engineered for your specialized applications. Whether the options are factory or field-installed in the equipment, Bard has your climate control solution. For a more detailed explanation of the solutions outlined here, please refer to the corresponding specification sheets listed below.

Dehumidification Capabilities:

Due to Indoor Air Quality concerns, many applications require a specified amount of outside ventilation air to be brought in during the cooling process. This usually brings an increased latent load into the building. A latent load that could be substantial during conditions of high humidity. Bard provides the solution to the increased latent loads with a factory-installed refrigerant based dehumidification circuit designed to be essentially sensible heat neutral during operation:

• The dehumidification circuit is available in Wall-Mount Air Conditioners, Wall-Mount Heat Pumps and Q-Tec Heat Pumps
• An additional heat exchanger coil located downstream from the evaporator coil reheats the supply air using the excess heat generated from the refrigerant discharged during the mechanical cooling mode
• If closed, a humidistat activates the reheat refrigerant circuit's 3-way valve to continue dehumidification process after the thermostat's sensible temperature requirements have been satisfied
• No adjustments required to refrigerant reheat system

For further information:
• WA Models Technical Information Link
• WG Models Technical Information Link
• WH Models Technical Information Link
• SH Models Technical Information Link
• QA Models Technical Information Link
• QH Models Technical Information Link
• QW Models Technical Information Link

Top of page.

Patented Ventilation Options:

Bard products are designed with your Indoor Air Quality requirements in mind. Several patented ventilation options offer application flexibility and range from barometric fresh air dampers to an energy recovery ventilators with sensible and latent heat transfer capabilities:

• Blank Off Plate - BOP: Installs inside the service door and prevents any outside air from entering the unit. The blank off plate should be utilized in applications where outside air is not required to be mixed with the conditioned air.
• Barometric Fresh Air Damper (BFAD): Allows up to 25% outside air. Damper opens during blower operation and closes when the blower is off.
• Motorized Fresh Air Damper (MFAD): Allows up to 25% outside air. The 2-position damper can be fully open or closed. Can be controlled by indoor blower operation or connected to an external managed-based system.
• Commercial Room Ventilator (CRV): Allows up to 50% outside air with built-in exhaust damper. The adjustable damper can be controlled by indoor blower operation or field controlled based on room occupancy. Complies with ASHRAE Standard 62-01 ("Ventilation For Acceptable Indoor Air Quality.")
• Economizer (EIFM): The economizer is designed to provide "free cooling" when outside air conditions are dry enough to satisfy cooling requirements without running the compressor. Features mixed air sensor
  and enthalpy control that monitors air temperature
  and humidity.
• Wall-Mount™ Energy Recovery Ventilator (WERV): Allows 200 to 450 cfm of outside air and exhaust while providing superior indoor comfort and humidity control. Complies with ASHRAE Standard 62-01. A unique "rotary energy recovery cassette" provides sensible and latent heat transfer capabilities during summer and winter conditions (refer to Bard Technical Guide F1403 for complete performance and application details.)

Depending on the type of equipment utilized, the ventilation options can be factory or field-installed:

Ventilation Capabilities:

For further information:
• Bard Specification Sheet F1722
• Accessory Technical Information

Top of page.

Hot-Gas By-Pass Applications:

Many specialized applications such as mobile medical coaches and television broadcast control rooms are sensitive to the electrical interference caused by a compressor motor cycling on and off. To ensure the uninterrupted performance of these critical applications, Bard offers a Hot-Gas By-Pass line of Wall-Mount air conditioners designed for outdoor temperature operation from -20°F to 115°F.

• Units operate continuously and modulate capacity without overcooling the occupied space.
• System capacity and head pressure control are the two primary modifications to the standard air conditioning product line. Both controls are accomplished in the refrigeration cycle design and independent of the electrical circuit.
• System Capacity Control is achieved by controlling the evaporator temperature with an expansion valve and a discharge bypass valve. This allows the air conditioner to operate continuously (without cycling the compressor on and off) while maintaining a constant supply air temperature. The system adjusts accordingly as the internal load changes.
• Head Pressure Control is essential to these applications since they will often operate when outdoor temperatures are below 60°. During low temperature operation, head pressure is controlled by flooding the outdoor coil with refrigerant rather than cycling the air across the coil.
• Temperature within the space is normally controlled by a wall thermostat that allows the user to manually switch between normal system operation during non-critical periods and the continuous hot-gas by-pass operation as needed.

Top of page.