• Introduction.
• Major components in RTU
• How Does a Rooftop Unit Work?
• Advantages of Rooftop Unit
• Disadvantages of Rooftop Unit 
• Applications of Rooftop Unit 

INTRODUCTION

• A rooftop unit is a type of HVAC system mostly found in commercial buildings. 
• These systems provide heating, cooling, and ventilation to a building.
•  Rooftop units are also sometimes found in residential homes.
•  A rooftop unit, as the name implies, is a packaged unit installed on the roof. These packaged units contain all air conditioning components

Major air conditioning component in RTU

1. Evaporator coil
2. Fan
3. Compressor
4. Condenser
5. Filters

1. vaporator coil Function in RTU

• The evaporator coil holds the chilled refrigerant that the compressor moves into it. 
• As the air from the blower fan moves over the coil, the cold refrigerant removes the heat from your home’s air.
• The refrigerant in the evaporator will absorb the heat.

2. Fan Function in RTU

• The fan pulls the air in from outside then through the dampers, filters and coils and it will then push this into the ductwork to be distributed around the building. 

3. Compressor Function in RTU

• A compressor is the heart of the air conditioning system.
• Compressor, a device for increasing the pressure of a gas by mechanically decreasing its volume

4. Condenser Function in RTU

• The compressor pressurizes the refrigerant gas and sends the refrigerant into the outdoor unit’s condenser coil. 
• A large fan pulls outdoor air through the condenser coil, allowing the air to absorb heating energy from the home and release it outside.
• During this process, the refrigerant is converted back to a liquid.

5. Air Filter Function in RTU

Air filters for rooftop air conditioning units provide an effective defense against airborne debris and contaminants that can damage commercial air conditioning units

RTU Working

• Flexible connectors are generally used to connect an equipment
• Once a rooftop AC unit is installed, cool, low-pressure refrigerant arrives at the compressor as a gas and then compresses into a hot, high-pressure gas as it flows into the condenser coil.
•  There, the metal fins on the coil absorb and disperse the heat, and the condenser fan blows the exhaust away from the building.
• As warm return air travels through the ductwork into the rooftop unit, fresh air enters as well for ventilation. Positioned over the return air duct are air filters to prevent contaminants from landing on the sensitive cooling equipment.

ADVANTAGES OF ROOFTOP UNIT:

• An RTU typically uses less energy.
• As the RTU is mounted on the roof, it does not take up any interior space.
• Installation is typically easier. Only the interior ducts need to be installed separately.
• Diagnostics and repair may be easier, as all the components are in one place.
• Reduced noise pollution
• Ease of maintenance
• Simple to design and operate

DISADVANTAGES OF ROOFTOP UNIT

• Higher operating and maintenance costs than the central systems.
• Not good for tight temperature control.
• Shorter equipment life.
• Filtration option Limited.
• Limited flexibility to change the component
• RTU’s are heavy and could cause damage to your roof membrane

APPLICATIONS OF ROOFTOP MUNIT

As per cooling and heating requirements, rooftop units are used in different places like:

• Supermarkets,
• Commercial buildings,
• Office buildings,
• Banks
• Movie theaters.