Maximizing Efficiency in DOAS: A Contractor’s Guide

Dedicated Outdoor Air Systems (DOAS) make it easier to maintain optimal indoor temperatures while reducing the workload on traditional HVAC equipment. However, these benefits are only possible when DOAS is appropriately integrated into a home or building’s existing system. 

In this post, we’ll examine the differences between DOAS and traditional HVAC systems at a high level and discuss a few ways to make them as efficient as possible.

DOAS vs. traditional HVAC systems 

Unlike traditional HVAC systems that bring outside air to be heated, cooled, and filtered, DOAS delivers preconditioned air into the building. This can reduce the strain on HVAC equipment, resulting in more efficient operations, higher energy savings, greater humidity control, and cleaner inside air. 

To maximize the benefits of a DOAS, evaluate its compatibility with the home’s overall heating, ventilation, and air conditioning system.

Here are a few ways to maximize DOAS technology’s efficiency when integrating it into a home. 

Be sure to recognize the power of ERVs

Using Energy Recovery Ventilators (ERVs) with your DOAS is like recycling. Instead of wasting energy in the air that’s already been heated or cooled, ERVs reuse it to treat the incoming outdoor air. This step is about choosing the right ERV to match the home’s needs. This can reduce energy bills and keep the air inside fresh and clean.

Decouple ventilation from heating and cooling 

The most efficient DOAS systems completely separate heating and cooling functions from air ventilation. In these setups, outside air conditioning by a heat recovery ventilator (HRV) or ERV is distributed through the home via ducting separate from the rest of the HVAC system. 

Take the time to size equipment accurately 

Choosing the correct size and components for your DOAS is critical for maximizing efficiency. Oversized systems waste energy, while undersized systems can’t effectively precondition air. The most accurate way to size equipment is to carefully calculate the building’s load requirements, considering factors like home size, occupancy, and local climate.  

Keep up with regular maintenance 

While homeowners are responsible for scheduling regular maintenance on their DOAS equipment, contractors can help nudge them in the right direction. At installation, it’s important to emphasize the value of having a professional come in for annual or even seasonal maintenance checks. 

These visits can help spot and address minor issues before they become larger and keep the DOAS working efficiently.

DOAS as a differentiator 

As the building industry continues to evolve towards greener and more efficient solutions, knowing how to sell and integrate DOAS effectively is a smart move for HVAC pros. 

With upskilling, careful upfront planning, and a routine of upselling customers on regular maintenance, HVAC contractors can leverage DOAS as a critical differentiator between themselves and competitors. 

To do this effectively, installers and their teams need to go beyond simply knowing how to install DOAS equipment—it’s equally important they understand how to properly design these systems to make them as efficient as possible. 

Back to What's New


ECCO Supply™ is one of Canada’s largest distributors of HVAC and related products. We proudly partner with top industry manufacturers in order to offer an extensive selection from the many industry leading suppliers whom we represent.