Rooftop HVAC units (RTUs) are very durable, weather-proof, and can withstand most extreme weather conditions. You’ve probably seen RTUs at your local shopping mall, hospital, school, and other public buildings with flat roofs. They work the same way as other external ground-level HVAC units or indoor HVAC units by providing hot or cold air to a building or home. RTUs are ideal for buildings with flat roofs and you’ll most often find them on rooftops of commercial buildings.

Here’s a detailed breakdown of how rooftop HVAC units work:

  • Fresh air is introduced into the RTU via the air hood or economizer on the side of the unit. Air hoods resemble mini-awnings with a small opening underneath it – this keeps snow and rain out while allowing air to enter.
  • After fresh air enters the RTU, it then gets mixed with the return air and  moves into the system’s filters where any contaminants are removed before it’s released into the building.
  • After being decontaminated, the fresh air is either cooled or heated depending on the RTU’s settings.
  • Once the air is the right temperature, the fan circulates it through the building ducts.

What Is a Rooftop HVAC Unit?

As mentioned above, RTUs work similarly to ground-level or indoor HVAC units, except they’re installed on the roof of a building. Many commercial buildings with flat roofs prefer RTUs because they conserve valuable space and they are less likely to be vandalized or stolen. They’re also easy to access and people in your building won’t be bothered by any noise the units produce. While older RTUs aren’t very energy efficient, there are newer models on the market that are much more energy efficient and can keep your building heated or cooled without resulting in huge monthly energy bills.

How is an RTU HVAC different from other HVAC systems?

Unlike other HVAC systems, RTUs are sometimes referred to as a “packaged unit” because they contain all the components of a heating system and a cooling system in a single box:

  • An intake for outside air that improves ventilation
  • An AC compressor
  • AC evaporator coils that absorb heat
  • AC condenser coils that release heat
  • A fan that blows heated air or cooled air through the air ducts

Most other HVAC units have separate components, but with RTUs you’ll find everything in a single unit.

Why Install Rooftop HVAC Units?

  • It saves valuable space. Even small commercial buildings need huge HVAC systems to maintain a comfortable indoor atmosphere for everyone inside. If you can install a RTU it saves you space, and in real estate every square foot matters.
  • They’re secure. Sometimes people destroy HVAC units looking for copper to resell, leaving you with no heating and no air, and an expensive problem on your hands. Installing a rooftop HVAC unit gives you an added level of security, because most RTUs can only be accessed from inside the building by someone who has a key to the door. Your RTU will also be safe from vandalism when it’s not on ground level.
  • They’re quiet. We’ve all been in a room when the heating or air conditioning switched on – the fans can often be heard over the sound of talking. All components of the RTU are located outside of the building, so you won’t have to worry about pesky noises or distractions.
  • Easy access for maintenance. With all components in a single box, your HVAC technician can access the RTU for maintenance and repairs.

For more information about rooftop HVAC systems, or if you have any other questions, please contact our team at Tri-Tech Energy today.