Frequently Asked Questions

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.

Chilled water equipment can have varying water flows, but a reasonable rule of thumb would be 3 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 GFCD-063XX is a nominal 18 ton unit so a water flow of 3 x 18 equals 54 GPM, can be calculated.

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.

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

The temperature differential can range from 10 to 12 degrees depending on water temperature and flow.

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.

HUMIDIFIER

HUMIDIFIER w LABEL

MODEL NUMBER

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 TB1-1 and TB1-2A or TB1-2B. There will be a jumper between these connections, remove the jumper. Finally, connect your EPO between connections TB1-1 and TB1-2A or TB1-2B.

TERMINAL BLOCK

JUMPER

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.

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.

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.

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

On air-cooled units built before April 2017, an auxiliary check valve is required and should be located 6′ to 10′ from the compressor on the discharge line if it has not been factory installed. On water/glycol-cooled units built after August 2017, the check valve is factory installed into the system.

Yes, the check valve prevents the unit from having a liquid migration on the high side of the system on cold days during the off-cycle.

In a gaseous state, the refrigerants are poor carriers of oil. Oil will begin to fall back down at vertical heights above 20 feet. Traps should be installed on the vertical rise of the discharge line, known as the hot gas line. Also, on the vertical suction line. One at the bottom of every vertical run and at every 15-20 feet in height. Refer to your IOM manual for more details on your respective units.

Traps assist the oil to travel vertically and to help with proper oil return.

An inverted hot gas line trap is required to contain the charge and the oil within the condenser coil during the “off” cycle. The trap should be installed at the top of every riser and at the condenser and should equal the height of the condenser coil.

Refer to your IOM manual for more details for your respective units. Follow the recommended tables.

Maximum line run is up to 200 equivalent feet. Consult with Data Aire Engineering for line runs longer than 200 equivalent feet. The ultimate responsibility for line size selection is that of the installing contractor or project engineer. Data Aire does not assume this responsibility. Data Aire recommends keeping the line runs as short as possible, and with few fittings to avoid pressure drops.

Maximum vertical line run is up to 200 equivalent feet.

Since the compressor sits in the evaporator section, condensers installed more than 10 feet below the evaporator section is not recommended and should be avoided. When the condenser is installed more than 10 feet below the compressor, you run into the possibility of creating flash gas at the top of the riser because of the increased pressure drop, (Liquid lift adds pressure loss of about 1 PSI per 2 feet.) so you might see a quicker wear and tear on the compressor. This also causes the compressor to lose capacity and increases its operating cost. Excessive liquid line pressure drop can cause poor evaporator performance. (A good way to check for flash gas is to compare the temperature of the liquid line exiting the condenser and the liquid line temperature entering the metering device. A huge temperature drop can indicate the presence of flash gas.)

Slope horizontal lines downward in the direction of the refrigerant flow. The recommended slope is 1/2″ (12 mm) for every ten (10) feet (3 m) of line length.

The oil in the suction line has a higher viscosity (thicker/denser) because it is at a lower temperature. Data Aire recommends reducing the riser size by one pipe size to increase the velocity of the refrigerant and assure oil return.

Yes, because the heat gain across the liquid line may cause the refrigerant to flash in the liquid line upstream of the metering line.

High compression ratio or bad pipe design can cause excessive noise. Check the pipe size and design and check the refrigerant pipe strapping on the building structure.

Design pipe size for a pressure drop equivalent to a 2°F saturation temperature drop. Discharge line pressure drop should not exceed 6 PSI for R-407C and 9 PSI for R-410A. Discharge line recommended gas velocity for proper oil return is 1,000 FPM (5.1 m/sec). The liquid line pressure drop for R-407C should not exceed 5 PSI or 9 PSI for R-410A. Liquid line recommended gas velocity should be between 200 and 300 FPM (1 to 1.5 m/sec). Excessive liquid line pressure drop can cause poor evaporator performance. (A good way to check for flash gas is to compare the temperature of the liquid line exiting the condenser and the liquid line temperature entering the metering device. A huge temperature drop can indicate the presence of flash gas.)

Yes, 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.

Yes, trapping is required on both the discharge and/or suction lines for vertical rise. 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. Refer to your respective units IOM Manual for more details.

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 36” on the two sides. Ceiling units require 36” on all sides.

Yes, trapping is required on both the discharge and/or suction lines for vertical rise. 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. Refer to your respective units IOM Manual for more details.

Upon receipt of the shipment, the receiver/installer should remove the unit from the truck with a forklift. They should uncrate the shipment as soon as possible and check for any freight damage. If any damage is found, they should notify the shipper (freight company not Data Aire) right away since they cover damage under their warranty.

The customer can check: to see that the crate is intact and not broken, that the doors close properly, and the components such as blowers have not shifted. They should visually check the outside for damaged packaging. After the unit has been received check for any damages. i.e door, piping, condensate pump (if equipped) and other components. The equipment should be moved to an indoor storage facility as soon as possible. They should also be very careful when removing any components, such as the door, and be sure to put them back the same way. Make sure all wires are secured tightly and package in a way that distributors/pipes cannot be bent or cracked. Everything should be very secure. Customer should inspect for any damage, loose wires, bent or cracked pipes.

One should use correct equipment to move our units. This depends on the unit or equipment and the tools they have available. It’s recommended that the equipment should be handled carefully using proper forklift, pallet jack or hand trucks. Be very careful as to not bend or pump pipes and wiring. Also, DX units need to have unit stay level to keep oil from spilling out.

Our equipment should be moved to an indoor storage room as soon as possible. They should be stored in controlled space or warehouse not exposed to the outside ambient so it does not freeze or heat up. They should be stored in dry, not humid, area with controlled temperature not below 30°F and not higher than 100°F. At minimum, they should store the equipment indoors and out of direct sunlight whenever possible. Also charge the system with dry nitrogen to help prevent any oxidation. If the unit is not being used right away, then it should be left covered in the original plastic covering, inside and away from cold ambient and corrosive environments.

The customer should make sure they have the correct order by checking the received unit against the acknowledgment, such as correct voltage and tonnage. If anything’s not correct, they should contact the factory as soon as possible. Also he should check all components to make sure they’re not loose. They should prepare to receive the units including prepping the piping, clear the area of obstruction, and site and front clearance. Make sure they have a clean work environment and stage the equipment where it is going to be installed. They should do a full inspection including checking the compressors and pipe and wiring connections. Make sure they have correct duct/pipe sizing and layout and also check for any loose wires or damaged pipes.

Our Installation, Operation and Maintenance Manuals (IOMs) contain standard instructions and guidelines for installation. They should follow our instructions in the IOMs and also follow their engineering design instructions and guidelines of their project manager. They also need to make sure to follow local and national codes. Prior to installation, they should check for damage, check voltage, make sure all components are tight, and have correct piping and vacuum. Installation process includes: securing the unit, piping, wiring low voltage to high voltage, and ducting (no instructions as each site dimensions vary). Once the unit is in position begin piping the unit. Release the nitrogen to atmosphere. Assemble all of the piping to be brazed. Then begin brazing with a nitrogen purge. Once brazing is complete, perform a leak check. Use dry nitrogen to pressurize the system to about 160 psi.  Record the pressure and wait a minimum of 30 minutes to make sure there are no leaks. Release the nitrogen then start to perform a vacuum on the system (DX units only. Vacuum to a minimum level of 500 microns and then perform a standing vacuum test. They need to do field wiring, charging for DX units, possible valve adjustments and any necessary programming/network setups.

They should fill out the start-up sheets and follow the recommendations in the IOMs. They should check for loose screws from shipping, and interlock from indoor to outdoor condensers and condensing units. Make sure there’s correct distance between units, wiring gauges are correct, and check the unit is set to IOM recommendations. Re check superheat and sub-cooling and check for any alarm history. They should inspect for proper installation including checking for leaks, wiring, and proper voltage. After start-up, they should check all controls, check for proper temperature and humidity and check that the unit is running properly. Make sure units are operating under safe design conditions. Make sure charging was done correctly. Address any strange behavior, even if customer doesn’t think it is a problem.

It depends on the room as each situation varies. There is no required run-in period. However the following is recommended. The unit should run for a couple of hours for the compressors and for the refrigerants to stabilize. They should let the unit run overnight or up to 24 hours and do a full inspection to make sure everything is running properly. Units should be run long enough to pass through any logic cycles (weekly scheduling, etc.) where we can see if logic is working as intended. Once the entire job site is set up and running as final layout, one should be able to see the operating temps, pressures, etc. Inspections should be performed quarterly.

Maintenance should be done quarterly. Maintenance schedule/checklist is listed in the IOMs.

The following components should be checked and maintained:
Humidifiers, belts, filters, bearings.
Screws should be checked to make sure they’re not loose.
All electrical connections tightened and all refrigerant connections tightened.
All operational pressures and temperature checked.
Compressors, motors, humidifiers and coils should be maintained quarterly or a minimum of 3 times a year.
Filters may need to be changed monthly or as needed, no longer than a year.
Nortec humidifier cylinder should be change every 6 months or as needed depending on the water supply.
Belts on older units (EC fans don’t have belts) should be checked and adjusted monthly.
Compressors should be checked for pressure and run times and alarms checked for history.
Filter driers should be replaced at manufacturer’s recommendation.
Filters should be replaced at manufacturer’s recommendation.
Blower belts should be visually inspected.
Condenser coils should be cleaned regularly.

Each Data Aire unit, which includes the optional smoke detector, is pre-wired by Data Aire to bring the various smoke detector relay features to a common terminal block within the unit electrical enclosure. The terminals of this block are labeled in accordance with the System Sensor nomenclature. Data Aire electrical diagrams also include the basic relay connections and nomenclature.

The System Sensor literature outlines a typical example of how to wire the optional smoke detector in a Data Aire unit to a typical fire detection system. It also shows how to wire multiple smoke detectors in multiple Data Aire units (i.e., in series) with the fire detection system. Because of the variations in fire detection systems, Data Aire has brought all available features of the System Sensor smoke detector to a common terminal block but the installing contractor must use this information in coordination with the plans and specification for the fire detection system and coordinate the wiring with the fire detection system installing contactor.

Please see the following document for installation instructions.

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.

Below is an installation and start-up checklist of recommended guidelines for keeping your compressor running optimally.

Below is the Service Troubleshooting Checklist with step-by-step questions and guidelines of our equipment.