New PVW 15 to 39 Ton "Splitable" Unit

The ideal systems for constant and variable air volume, constant temperature applications available from 5 to 100 tons.

• floor-by-floor building comfort
• design flexibility
• variable air volume savings
• DDC or microprocessor-based controls
• single-packaged economy

Features / Benefits

Floor-by-floor design flexibility

Dunham-Bush units offer the maximum design flexibility for new construction, replacement and renovation jobs. Individual floors can be occupied, one at a time, as the units are installed. Individual tenants utility metering is also possible. Whenever interior layouts are updated or modified, the systems allow for quick and easy changes without disrupting the other building occupants.

Operating savings

When you choose the water-cooled unit you will get a package that can cool, dehumidify, and circulate air – all under a DDC or microprocessor master control (VAV only) that assures minimum energy consumption at full and part load.

The VAV units have an advanced solid-state microprocessor system that assures maximum operating economy. This computer brain constantly monitors unit discharge air temperature and compares it with conditioned space temperatures. Logic circuits then sequence cooling stages to provide just the amount of mechanical cooling necessary for stable, comfortable conditioned space temperatures.

Choose either an industry standard DDC or the Honeywell model W7100A discharge air 6-stage temperatue controller.

For VAV units, the microprocessor/DDC provides precise control over the leaving-air temperature by narrowing the throttling range around the set point.

This is the most important ingredient in true energy saving systems. Using this system, a truly integrated field-supplied air or water side economizer is possible.

Additional savings are available by ordering the variable frequency fan drive option. All hardware and associated controls are factory installed.

All models are available with a factory-installed Hydronic economizer option. An aquastat senses the cooling tower water, and, if the water temperature is low enough, circulates it through a water cooling coil in the unit. This keeps the compressors off for a long period of time and provides additional unit operating savings.

Convenient installation and minimum maintenance

The units serve any building… schools, offices, libraries, or high rises. Just set the packaged cooling unit in the equipment room or conditioned space, attach the ductwork and install the self-contained system-powered variable air volume (VAV) terminals.

The packaged cooling unit, in its rugged compact package, can be placed in a variety of locations whether in the equipment room or the conditioned space. Each unit can be ordered with either vertical or horizontal air discharge. The factory-installed piping and the pre-wired electrical center simplify field connections.

The units are designed to provide years of trouble-free service with low maintenance.

All components of the unit are mounted on a sturdy steel frame encased in a painted cabinet of heavy-gauge steel. This rugged construction provides strength and durability, with excellent protection against damaging dirt or moisture.

Easy-to-remove panels provide complete access to internal components and controls. The time-tested serviceable scroll or semi-hermetic compressors are sealed against dirt and moisture contamination. Their precision parts have minimum-wear surfaces that are thoroughly protected by positive pressure lubrication.

Dual scroll semi-hermetic compressors deliver quiet, reliable high cooling capacities at low cost. The anti-short cycle circuit eliminates short cycling and simultaneous start-up of compressors if any of the safety devices open. This feature minimizes power surges.

VAV units incorporate automatic capacity control at partial load, provided by electric unloaders and compressor cycling that tailor cooling capacity to cooling requirements. A temperature-actuated microprocessor cycles the electric unloaders and compressors to ensure positive control of the supply air temperature as it leaves the unit. The result is lower operating costs.

Positive compressor protection is assured on all units by the use of calibrated, single-phase protection circuit breakers and high- and low-pressure switches.

Face split coils are specially designed for true, independent two (2) circuit operation.

Forward-curved fans move large volumes of indoor air quietly and at a lower rpm than most comparable fans. The compact housing gives the fans superior capability for vertical or horizontal supply air discharge.

High-efficiency condensers provide maximum exposed heat-exchange surface for greater heat rejection with less water consumption.

Hot gas bypass prevents indoor coil freeze-up at very low loads. Hot gas bypass refrigerant control assures reliable cooling operation on those rare occasions when the load drops to extremely low levels. During those low load periods, when the system is experiencing minimum airflows, the hot gas bypass valve allows space condition to remain comfortable.

Pre-wired electrical control center contains all control devices. Terminal block provides for a single-point field power connection.