The enVerid HVAC Load Reduction® (HLR) system enables buildings to comply with ASHRAE Standard 62.1 without relying solely on high volumes of outside air for ventilation. The ASHRAE 62.1 standard defines two procedures for mechanical ventilation: the Ventilation Rate Procedure (VRP) and the Indoor Air Quality Procedure (IAQP). The VRP is an older procedure that depends upon a brute force approach that is extremely inefficient. The IAQP, in contrast, is a newer, calculated approach that doesn’t depend entirely on outside air. The HLR system takes advantage of the ASHRAE 62.1 IAQP guidelines to provide indoor air quality while saving energy.
The VRP relies solely on bringing in high volumes of outside air to continuously replace indoor air and remove the contaminants generated by people, building materials, and furniture. Unfortunately, the outside air doesn’t start out at room temperature and needs to be heated or cooled to become comfortable. This consumes a tremendous amount of energy. On average, 44% of energy used in a commercial building comes from the HVAC system and wasteful procedures like the VRP are why. Furthermore, the outside air brought in to replace the indoor air contains all of the pollutants and ozone from the outside, adding things like car exhaust to the inside air.
The Indoor Air Quality Procedure
By not relying solely on outside air, the IAQP allows for the use of air cleaning to reduce contaminants in the indoor air. Using sorbent-based indoor air cleaning technologies like HLR modules can reduce outside air intake by 60-80%, reducing the HVAC heating and cooling load and keeping outdoor pollutants outside the building. Since outside air contributes significantly to the HVAC heating and cooling load, especially peak loads, reducing the intake of outside air lets buildings use smaller, cheaper HVAC systems. Overall, IAQP and HLR Technology increases building energy efficiency and can provide better indoor air quality. The ASHRAE Standard 62.1 itself states as much:
“The IAQP may allow for a more cost-effective solution to providing good air quality,” and “achieve better air quality than VRP.”
To provide further clarification on the use of air cleaning, ASHRAE issued an official interpretation of the IAQP on January 25, 2015 which publicly states and affirms that the use of air cleaning as a method to remove contaminants of concern is an acceptable way to decrease outdoor airflow. According to Dennis Stanke, former chair of ASHRAE 62.1, Interpretation IC 62.1-2013-4 OF ANSI/ASHRAE Standard 62.1-2013 Ventilation For Acceptable Indoor Air Quality:
“Using the required mass balance analysis to determine zone outdoor flow rate, the phrase “other relevant parameters” allows the use of gaseous air cleaners, particle filters, or both to remove contaminants and thereby reduce the outdoor air flow required for a zone without air cleaning.”
Learn more about using the IAQP in our May 17, 2021 technical webinar for NAESCO with Dr. Marwa Zaatari, Partner – D ZINE Partners and Anurag Goel, Director of Sales & Application Engineering, enVerid. Watch the webinar on YouTube here. You can also take our free online professional development course, “Improve IAQ, Reduce Carbon Emissions, and Save Energy with Performance-Based Ventilation Design” on AEC Daily here.
International Mechanical Code Compliance
In addition, the International Mechanical Code (IMC) specifically allows for the use of ASHRAE’s IAQP. Section 403.2 of the IMC states:
“Where a registered design professional demonstrates than an engineered ventilation system design will prevent the maximum concentration of containments from exceeding the obtainable by the rate of outdoor air ventilation determined in accordance with Section 403.3, the minimum required rate of outdoor air shall be reduced in accordance with such engineered system design.”
In the official IMC Commentary, it states:
“An engineered ventilation system is more of a direct method of controlling air quality and would be classified as an ‘Indoor Air Quality Procedure’ in ASHRAE 62.1.”
enVerid is Here to Help
IAQP implementations are growing rapidly as building owners become aware of the significant advantages. The ease of using HLR modules has encouraged the adoption of the IAQP. enVerid’s IAQP Calculator, available online with an account, greatly simplifies the IAQP design process and produces all of the necessary compliance documentation, which can be copied directly into construction design documents. In addition, enVerid has a dedicated team of engineers who will work closely with you to calculate the air cleaning and outside air volumes that best meet your project requirements, as well as providing detailed advice on how to integrate HLR modules into HVAC design. You can also take our free online professional development course, “Improve IAQ, Reduce Carbon Emissions, and Save Energy through Performance-Based Ventilation Design,” an overview of the IAQP with case studies that will help you to earn professional development credits from ASHRAE, USGBC, International WELL Building Institute, and numerous other certification bodies. Learn more about the course here on AEC Daily. enVerid also works closely with contractors and factory-trained professionals to ensure the HLR modules are installed and commissioned correctly.
By efficiently scrubbing existing temperature-controlled air, enVerid’s HLR system helps building managers and designers embrace the ASHRAE Standard 62.1 IAQP and reap the dramatic energy savings and IAQ benefits that enVerid’s approach can provide.