What is Package Air Conditioners?
A packaged air conditioner (PAC) is a self-contained HVAC unit that encloses all major components compressor, condenser, expansion device, evaporator coil, and air handler in a single outdoor cabinet, delivering conditioned air to your space through supply and return ducts.
Explanation
Because everything sits in one weather-proof box (often on the roof or a concrete pad outside), you only run ductwork indoors, not refrigeration lines. The compressor forces refrigerant through the condenser coil, where outdoor air removes heat; the cooled refrigerant then flows to the evaporator coil, where a blower pushes warm indoor air across it to absorb heat and humidity before sending the cooled air back to you through the ducts.
Contact us for the repair, servicing, and supplies of package air conditioners for commercial and industrial settings.
What are the Components of the Package Air Conditioner?
A packaged air conditioner contains the compressor, condenser coil and fan, expansion device, evaporator coil and blower, air filter, drain system, and control panel/thermostat all sealed inside one weather-proof cabinet.
Components Breakdown
Compressor
This is the “heart” of the unit. It compresses low-pressure refrigerant vapor into a high-pressure, high-temperature gas so the heat can be rejected outdoors. In most light-commercial PACs you’ll find scroll or rotary compressors sized from 3 to 70 tons.
Condenser coil & fan
The hot gas flows through copper or micro-channel aluminum coils while a top-mounted fan draws outdoor air across them, pulling heat away from the refrigerant. Typical surface areas range from 10 ft² in 3-ton models to 80 ft² in 20-ton units for efficient cooling.
Expansion device
A thermostatic expansion valve (TXV) or electronic expansion valve meters the liquid refrigerant into the evaporator. By dropping the pressure, it lowers the refrigerant temperature so it can absorb heat from your indoor air.
Evaporator coil & blower
Inside the same cabinet, a centrifugal or ECM-driven blower pushes warm return air from your ducts across the evaporator coil. The refrigerant inside the coil absorbs both sensible heat and humidity, sending cool, dry air back to you. Blower airflow is usually 350–450 CFM per ton.
Air filter
A disposable or washable filter (often MERV 8–13) sits before the evaporator to trap dust and protect the coil. You should inspect or replace it every 30 days in dusty environments.
Drain pan and condensate line
As moisture condenses on the cold coil, it drips into a corrosion-resistant pan and exits through a PVC drain line. Keeping this line clear prevents water damage and mold growth.
Control panel & thermostat
An onboard control board manages compressor cycles, fan speeds, safety switches, and communicates with an indoor or rooftop thermostat. Modern PACs may include BACnet or Modbus interfaces for building-automation tie-ins.
What are the Types of Package Air Conditioners?
The main types of packaged air conditioners are cooling-only packaged units, packaged heat pumps, packaged gas-electric units, dual-fuel (hybrid) packaged units, and packaged terminal air conditioners (PTACs).
Types of Package Air Conditioners
Cooling-only packaged unit
This is the classic rooftop or ground-mounted box that gives you chilled air in summer and pairs with electric strip heaters for light heating if needed. Capacities run from about 3 to 20 tons with typical efficiencies of 13–18 SEER.
Packaged heat pump
Instead of electric heat strips, the refrigerant flow reverses in winter so the same unit can warm you. These models reach 14–20 SEER and 8–10 HSPF, making them popular where electricity is cheaper than gas.
Packaged gas-electric unit
Here, the cooling section is standard air-conditioning, but heating comes from an 80–95 AFUE gas furnace burner inside the cabinet. You get one compact rooftop box while still enjoying the power of gas heat on cold nights.
Dual-fuel (hybrid) packaged unit
This combines a heat pump and a high-efficiency gas furnace. The heat pump handles mild weather; when outdoor temperatures drop (usually below 35 °F/2 °C), the control board switches you to gas heat automatically, cutting utility bills in mixed climates.
Packaged terminal air conditioner (PTAC)
You’ve seen these below hotel windows: each self-contained chassis slides through a wall sleeve to cool (and often heat) a single room. PTACs range from 0.75 to 1.5 tons and plug into 208–230 V outlets, giving you individual room control without ductwork.
By matching the right packaged unit type to your climate, fuel costs, and space constraints, you get efficient comfort from a single, self-contained system while minimizing installation time and maintenance hassle.
What is the Construction of the Package Air Conditioner?
A packaged air conditioner is built as one weather-proof steel cabinet that encloses the refrigeration circuit, separate evaporator and condenser sections, an insulated supply-and-return air plenum with blower, a condensate drain pan, washable air filters, and a dedicated electrical/control compartment all mounted on a rigid base frame ready for rooftop or ground installation.
Construction For Package Air Conditioner
Weather-proof cabinet
The outer shell is usually 18- to 22-gauge galvanized steel with a baked-on powder coating to resist rust and hail. Double-skin panels are foam-insulated (about R-6) so you lose less cooling to the sun and hear less fan noise inside.
Rigid base frame
A welded steel rail under the cabinet spreads the weight (often 300–2,500 kg depending on tonnage) and gives you forklift, or rooftop-curb pick points. Factory-installed vibration pads keep the compressor hum from transmitting into your building structure.
Refrigeration circuit zone
On one side sits the sealed loop compressor, condenser coil, and expansion device, plus a propeller fan that blows outdoor air across the coil. All service valves and sight glasses face a hinged access door so your technician can attach gauges without disturbing the duct connections.
Evaporator and air-handling zone
The opposite side holds an A- or slab-shaped evaporator coil and a belt- or ECM-driven blower. Warm return air from your ducts crosses this coil, sheds heat and moisture, then the blower pushes the cool air back to you. Airflow is factory-balanced at roughly 400 CFM per ton, but you can adjust pulley taps or ECM speed on site.
Supply/return plenums and filters
A sheet-metal plenum channels supply air upward (for rooftop down-flow models) or horizontally (for curb-side discharge). Washable or disposable filters slide out on rails ahead of the coil so you can swap them in minutes.
Condensate management
Under the evaporator, a corrosion-resistant polymer drains pan slopes to a ¾-inch PVC stub. Keep that line clear and you won’t see water stains or mold around the unit.
Electrical and controls compartment
A separate, gasketed chamber houses the contactor, capacitor, transformer, and circuit board. Pre-wired terminal blocks let you land the thermostat cable or tie into BACnet/Modbus without fishing through refrigerant pipes.
What is the Working Principle of Package Air Conditioner?
A packaged air conditioner works by running a closed-loop refrigerant cycle that pulls heat and moisture from your indoor air at the evaporator coil and dumps that heat outdoors at the condenser coil all inside one self-contained cabinet.
Working Principle of Package Air Conditioner
Warm return air meets the evaporator
Your ductwork sends room air (around 75 °F / 24 °C) across the cold evaporator coil. The refrigerant inside the coil is about 40 °F / 4 °C, so it soaks up heat and humidity. The blower immediately pushes the now-cool, dry air (roughly 55 °F / 13 °C) back to you through the supply ducts.
Compressor raises pressure and temperature
The refrigerant vapor leaves the evaporator at low pressure (≈ 70 psi in a 3-ton unit). The sealed compressor squeezes it to roughly 250 psi, driving the temperature above 100 °F / 38 °C so outdoor air can remove the heat.
Condenser coil rejects heat outdoors
A top-mounted fan pulls outside air through the condenser fins. That air often 95 °F / 35 °C on a hot day, still feels cooler than the 100°F plus refrigerant, so heat flows out. The vapor condenses into a high-pressure liquid at close to ambient temperature.
Expansion device drops the pressure
The liquid refrigerant passes through a thermostatic or electronic expansion valve. Pressure and temperature plunge, bringing the refrigerant back down to about 40 °F. This cold, low-pressure mix returns to the evaporator, ready to absorb your indoor heat again.
Controls keep everything balanced
A thermostat in your space starts and stops the compressor and fans to hold your set point. Typical airflow is factory-tuned to around 400 CFM per ton, ensuring the coil stays cold enough to wring out moisture without frosting.