Leasing Space with a Dedicated Outdoor Air System (DOAS)

To maximize building energy efficiency, GHT recommends adopting a Dedicated Outdoor Air System (DOAS). Learn more about the benefits a DOAS can deliver to tenants and building owners and how a DOAS saves energy and space compared to other HVAC systems.

What is a DOAS?
DOAS stands for Dedicated Outdoor Air System. It is a high performance HVAC system that maximizes building energy efficiency and usable square footage. A DOAS achieves these benefits through two main processes:
▪ It uses water to transport heating and cooling energy, consuming less energy and requiring smaller equipment compared to a typical all-air system
▪ It preconditions the required outdoor air separately from tenant space conditioning air, which reduces the quantity of air that circulates through the building and minimizes the size of associated ductwork

How Do Tenants Benefit From a DOAS?
Compared to typical all-air systems, the energy use reductions and smaller HVAC infrastructure that a DOAS can offer creates the potential for:
▪ Higher ceilings
▪ Increased usable square footage
▪ Superior energy efficiency
▪ All levels of LEED certification, including Platinum
In addition, a DOAS can virtually eliminate the overcooling associated with Variable Air Volume (VAV) systems that have fixed outdoor air percentages.

How does DOAS save energy compared to other systems?
▪ Moving energy in water is 2/3 more efficient than moving energy in air
▪ A DOAS uses 70-80% less fan energy than a typical all-air system because it moves a smaller quantity of air
▪ A DOAS generates cooling energy with warmer water than a typical VAV system, which increases chiller efficiency

For more information about DOAS and recent GHT projects utilizing this system, Download the PDF outlining the most important aspects of Dedicated Outdoor Air Systems.