Choosing a Dedicated Outdoor Air System (DOAS)

Published On: October 17, 20220 Comments on Choosing a Dedicated Outdoor Air System (DOAS)Tags: Last Updated: January 30, 20242.4 min read

Manufacturers are offering cutting-edge new technology to enhance indoor air quality to meet the industry’s demanding current ventilation regulations. One of these approaches is the installation of dedicated outdoor air systems (DOAS), which can help control humidity and temperature. A DOAS unit can be useful in schools, hospitals, businesses, and other commercial settings. Technicians and end users must comprehend how these systems function and how crucial they are as they gain popularity across the USA and Canada.


Despite not being the major source of cooling, DOAS devices improve the efficiency of the main HVAC system. These devices work by bringing in fresh air without the assistance of other cooling and heating devices. This prepared air will ultimately reduce the amount of fan energy used by the primary HVAC system and enhance the general quality of the indoor environment. These devices may have variable capacity compressors and can be air-cooled, water-cooled, and chilled water-cooled.

How to Get Started

Selection software is typically used to specify a DOAS unit. This concentrates on the unique wants and requirements for fresh air while keeping the installation’s fundamental parameters in mind. The software will determine the performance goals and suggest further alterations to the fundamental package. Water-source heat pumps and modulating hot gas reheat are two alternatives available for a variety of fresh air systems that manage a range of CFM and tonnage.

Other fresh air systems might use direct expansion and an enthalpy wheel for energy recovery. The device should be able to deliver “neutral” air between 72°F and 75°F at 50% RH and handle the substantial latent ventilation load. The device will eliminate moisture from the main supply of fresh outdoor air by separating the sensible load from the latent load. This lessens the burden on the main air conditioner that will be utilized to chill the room. In the end, this results in more efficiency, improved indoor air quality, and lower total costs.

It’s critical to comprehend all the advantages before determining whether a DOAS unit is necessary

The indoor air quality will be considerably enhanced by eliminating external pollutants before they enter the structure. Additionally, this will improve the efficiency of the primary cooling system. Mold is less likely to grow when moisture from the incoming air is removed during the dehumidification process. These components have the potential to harm building inhabitants’ health. Separating the ventilation demand from the primary cooling or heating unit also results in energy savings.

Dedicated Outdoor Air Systems have developed into a crucial part of a general strategy for HVAC installation. The significance of DOAS units will increase when governments impose stricter energy regulations in the manufacturing process as a result of worries about climate change. These kinds of devices will continue to be employed well into the future as a result of ongoing advances, making them even more effective.

Share This Tip With Your Friends!

About the Author: Handyman tips team

The Handyman Tips Team is a group of authors that provides tips on the Handyman Tips website. The Handyman Tips team consists of real handymen, contractors, carpenters, woodworkers, and experts in home repairs, appliance repairs, and landscaping. The team is always there for visitors to the Handyman Tips website. If you can't find the answer to your question on the Handyman Tips website, one of them will reply to you almost immediately if you contact them through the Ask the Handyman page!