Frequently Asked Questions

Frequently Asked Questions

You’ve got Questions.  We’ve got Answers.

Below is a list of common questions and answers concerning Data Aire products. Simply click on a question to view the answer.  Feel free to send us any additional questions by clicking HERE. We will get you answers as soon as possible.

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Frequently Asked Questions

How can I determine the tonnage of my unit?

The easiest way to determine tonnage of a unit is the model number on the nameplate. Tonnage is usually the first and/or second numbers in the model number. The nameplate contains a number of other key pieces of information as well. Nameplate diagrams are shown below.

gForce Model ID FAQ

Unit Tonnage FAQ


What piping sizes should be used to connect split air-cooled Data Aire units?

The best way to get this information is to review the Operations and Maintenance Manual that comes with the unit. If you cannot locate the Manuals they are also available on this website in the Download Literature section. Connections tables are shown below.

Piping Sizes FAQ

Can I install an Emergency Power Off (EPO) connection, and if so, where is it installed?

Yes, an Emergency power Off (EPO) connection can be installed on your Data Aire unit. First, locate the electrical panel on the Data Aire unit. Terminal blocks can be either vertical or horizontal (see top two photos below). Next locate connections 1 and 2. There will be a jumper between these connections, remove the jumper. Finally, connect your EPO between connections 1 and 2, see bottom two photos below.

Emergency Power Off FAQ

Do Data Aire units ship with refrigerant charges in their systems?

Data Aire units that have a self-contained refrigerant system, such as packaged and water/glycol-cooled units, DO ship with a refrigerant charge. Air-cooled units DO NOT have a charge, but may have residual refrigerant from factory run testing.

How many pounds of refrigerant are in my Data Aire unit?

Data Aire provides units with either R-410a or R-407c. Unit with R-410a require 3 pounds of refrigerant per nominal ton. Units with R-407c require 2.55 pounds per nominal ton. Some unit may have dual circuits.

These are “rule of thumb” guidelines. The refrigerant charge is dependent of several factors including line size and length of run. Each Data Aire unit is shipped with an installation, Operation and Maintenance manual that detail the refrigerant charge procedure and requirements. These manuals are also available online in the “Literature Download” section.

On older models with R-22 use 3 pounds per nominal ton.

How much clearance around my Data Aire unit is required for servicing?

Data Aire recommends a minimum of 36” on the front and two sides of floor-mounted units. Units with EC motor and plug fans require 40” on the front and two sides. Ceiling units require 36” on all sides.

What are the typical discharge and suction pressures?


  • Discharge: 340 to 415 PSIG
  • Suction: 100 PSIG or greater


  • Discharge: 240 to 295 PSIG
  • Suction: 58 PSIG or greater

What are the typical temperatures for superheat and sub-cooling?

  • Superheat: 8-15 °F (with 68-74 ° return air)
  • Sub-Cooling: 8-10 °F (depending on ambient conditions)

Are traps required in refrigerant piping run with air-cooled units?

Yes, trapping is required on both the discharge and/or suction lines. Discharge lines, also called hot gas lines, should be trapped at the top (inverted) and bottom, as well as every 15-20 feet of vertical rise as applicable. Suction lines should be trapped in a similar fashion.

How much steam is generated by the Nordec humidifier? Can it be adjusted?

The amount of steam generated depends on the model of humidifier you have in your Data Aire unit. To determine the model number, locate the product description label on the Nortec humidifier. Match the model number to the table below to determine the amount of steam generated. All humidifiers can be adjusted within the range shown. Factory setting is 60% of capacity. Additional details are available in the Operation and Maintenance Manual shipped with the unit.

Nordec Humidifier FAQ

Is an air vent valve required in the piping when an expansion tank is used?

Air vents must be installed in various locations in the piping system to purge air and are required at the highest point in the piping system. One of the most common problems in water/glycol systems is the presence of air in the condenser loop. In addition, an expansion tank is recommended on glycol systems. The Operation and Maintenance Manual shipped with the unit (or available for download on this website) illustrates typical field piping for a glycol system.

How are the fans controlled on the heat exchanger (air cooled split systems)? Can they be adjusted?

Data Aire air-cooled condensers utilize a fan speed controller.  On single fan units this is the only means of control.

Multiple fan condensers are provided with fan speed control on the first motor (nearest the header.)  The fan speed control is pre-programmed and there is no need for field adjustment.  The header fan will cycle with the head pressure.

Units with R-410a the starting pressure is 320 PSIG with the fan at full speed 400 PSIG.  Units shipped with R-407c the starting pressure is 220 PSIG with the fan at full speed 285 PSIG.

When the condenser heat load exceeds the output capacity of the fan speed controller fan, the second fan is turned on to full speed in conjunction with the fan speed controlled motor and the fan speed controlled motor modulates to a new start pressure.  This allows the condenser load to be modulating by the cooling effect of two fans instead of one.

Additional motor (subsequent to the fan speed control operated motor) on multiple fan heat exchangers are cycled by ambient sensing thermostats.

Ambient Fans Heat Exchanger FAQ

What is the GPM requirement for my Data Aire chilled water unit?

Chilled water equipment can have varying water flows, but a reasonable rule of thumb would be 2.5 GPM per ton. Under typical operating conditions, such as 72 degrees with 45 degree entering water temperature (EWT), this will yield a water temperature differential of about 10 degrees (LWT equals 55 degrees) For instance, model DACU 1834 is a nominal 18 ton unit so a water flow of 2.5 x 18 equals 45 GPM, can be calculated.

What is the factory setting of the thermal expansion valve (TXV)?

The factory setting for the TXV valve is the mid-range of the valve adjustment stem. The table below shows the settings per valve model. The model number is stamped on the valve body, or in some cases labeled on the top.

Thermal Expansion Valve FAQ

What is the anticipated difference in temperature from water-in and water-out for a chilled water unit?

The typical differential should be in the range of 10 to 12 degrees.

What is the anticipated difference in temperature from water-in and water-out for a water-cooled unit?

The temperature differential can range from 10 to 50 degrees depending on water temperature and flow.

Where is the location to pipe in a check valve on air-cooled split systems, per circuit?

A check valve is recommended and should be located 6′ to 10′ from the compressor on the discharge line.

What are the low and high-pressure switch settings?

Low pressure cutout switch

  • R-410a  50 PSIG
  • R-407c  28 PSIG

High pressure switch

  • R-410a  610 PSIG
  • R-407c  400 PSIG

What is the pressure drop across the coils of the Data Aire unit and/or the unit itself?

There are a number of factors that can affect these results as well as the configuration of the unit. In general, the pressure drop across the coil is .3″ to .5″, and for the entire unit the pressure drop will range between 1.5″ and 2.5″. For more specific information on a particular unit, contact the Engineering Department.

What are the pressure drops across components such as: plate and fin heat exchanger, regulating valve, and the units piping?

Pressure drops for individual components are not published because they vary from unit to unit. Heat exchangers typically represent approximately 45% of the total loss.  Water regulating valves account for approximately 45% of the total unit loss, as well. The remaining 10% is internal piping. Exact breakdowns of these component values for specific units can be obtained through Data Aire’s Engineering Department. Please be ready to provide the unit’s model and serial number.

Where is the low voltage wiring connected between the evaporator and the condenser or fluid cooler heat exchangers?

FLOOR UNITS – First locate the electrical box in the indoor unit and then the terminal block within the electrical panel. (See photos below) On the indoor unit, terminal block connections 46 and 47 connect to the indoor evaporator. On the outdoor unit, 39 and 40 should be connected to the outdoor condenser.

CEILING UNITS – First locate the electrical box in the indoor unit and then the terminal block within the electrical panel. On the indoor unit terminal block connections 39 and 40 connect to the indoor evaporator. On the outdoor unit, 39 and 40 should be connected to the outdoor condenser.


Wiring Diagram