Why Ventilate

Next Steps for the HVAC Industry

Prepared by US-EcoLogic/TexEnergy Solutions | Lauren Helixon, Sanaul Huq, & Siying Zhang

Ultimately, the adoption of 2012 IECC and ASHRAE 2013 will increase overall activity in the HVAC industry in all regions; bringing more awareness, public interest, and innovation to the market. Existing challenges and deficiencies with mechanical ventilation systems, especially with air exchange systems, will be a primary area for industry advancement. Specifically, issues associated with static pressure and duct run, over-ventilation, system costs and noise, and challenging climates will be at the forefront.

Static Pressure and Duct Run

Like many other building components, mechanical ventilation systems must overcome realities of physics. The primary impediment to
mechanical air flow is friction. As air moves through a duct it loses pressure and will not flow at the same rate at the end of a duct as it did when leaving the central unit. Additionally, any kink or curvature in the duct itself will further diminish the air flow rate, making proper installation an important factor in a well-operated ventilation system. Many energy raters will inspect homes to ensure the duct system is free of obstructions caused by angles or ill-positioned duct support systems. The integrity of the entire ventilation system and associated operating costs can be significantly compromised due to incorrectly installed duct-work.

Over-ventilation

Primarily a concern for air exchange systems, over-ventilation occurs when a home or building is not tight. The conditioned air supplied to the home can leak out through crevices that were not sealed in the building envelope. This is why mechanical ventilation is an effective strategy when combined with a tight building. Over-ventilation results in wasted air and increased energy costs associated with HVAC.

System Costs and Noise

HVAC systems are one of the most critical components of home and building design and are one of the most expensive – in both installation and operation. Heating and cooling account for 50% of all home energy needs, making it the leading energy cost for homeowners. The potential for an increased demand on whole-house ventilation will significantly affect the HVAC market. Manufacturers who take advantage of this situation by decreasing costs associated with the design, installation, and repair of HVAC systems will capture a significant portion of the market. In addition, refining HVAC systems to be smoother and quieter will be a major selling point.

Challenging Climates

A leading impediment to HVAC systems is the condition of the outside air before it is brought in from the outside. Humidity is a major challenge when brining air inside from outdoors. Additionally, it is typically necessary to condition air through an exchange air system in order to supply cool air during hot months and warm air during winter. The desire for humidity and temperature control of incoming air results in additional costs. By investing in more automation controls, building occupants and homeowners could regulate the operation of ventilation in order to ventilate during periods of lower humidity and appropriate temperatures (i.e. bringing air in at night if cooler air is desired). Evaluating outdoor air conditions prior to ventilating requires simple transducers that can communicate with the HVAC system.
Code is getting more stringent; buildings are becoming tighter; and there is a significant need for mechanical ventilation. Mechanical ventilation is needed to achieve acceptable indoor air quality and support energy efficient design. As the industry and market respond to new energy and sustainability requirements there will be increasing innovation as it relates to ventilation.