Ventilation basics

Now is a good time to verify HVAC systems deliver outdoor airflow rates as originally designed and meet current minimum ventilation code requirements. Over time, equipment within ventilation systems such as dampers may fail. A re-commissioning effort can confirm equipment is operating as originally designed and that spaces are adequately ventilated for premium guest experience.

The solution to pollution is dilution 

The above expression captures the essence of boosting ventilation. Bringing in more fresh air dilutes potentially contaminated air that has been recycled and respirated inside the building. While any building should be ventilated to meet codes, an opportunity exists when renovating to augment fresh air volumes indoors.

It’s an ideal time to consider infrastructure that can amplify ventilation in high-volume spaces and/or during crowded events. Ventilation demand control strategies and energy recovery equipment can reduce the energy impact.

Filtration

When upgrading or renovating, hotel owners may consider enhancing mechanical systems to add greater filtration flexibility. Most commercial buildings use MERV rated filters, an acronym that stands for Minimum Efficiency Reporting Value. Filters range from 1 to 16, and many commercial buildings use a MERV 8. MERV 8 is typically in compliance with ventilation standards such as ASHRAE 62.1-Ventilation for Acceptable Indoor Air Quality. Higher MERV numbers contain media capable of capturing smaller particles (such as viral particles), which is why healthcare settings typically use at least MERV 13. The downside to higher filter ratings is that more energy is needed to push air through the media. Consequently, an investigation of HVAC capabilities and capacities is necessary before making any filtration changes.

The minimum recommendation for filtration comes from the American Society for Heating, Air Conditioning and Refrigeration Engineers (ASHRAE). During the pandemic, ASHRAE recommended that capable buildings switch to MERV 13 filtration to help mitigate the transmission of infectious aerosols. Integrating this flexibility will add resilience to any hotel and help reassure guests of the indoor air quality.

Inactivating potential pathogens

Air-cleaner technology saw a frenzy of activity during the pandemic, resulting in new equipment offerings including new applications of tested technologies. The use of ultraviolet germicidal irradiation (UVGI) in HVAC systems is a proven technology that has been used effectively for both surface and air disinfection. Because in-duct UVGI systems are isolated within ductwork or equipment, there is little risk of human exposure.

Upper-Air UVGI solutions now allow the placement of ultraviolet lamps in occupied spaces, either suspended from ceilings or installed on walls, to inactivate airborne and surface-bound viruses and bacteria. Designing the right UV solution balances equipment selection and the needs of the space with ensuring powerful UV rays will not harm occupants.

Healthier humidity

Indoor humidity levels of at least 40 percent can substantially suppress transmission of common pathogens that cause flu and COVID-19, among others. Most buildings have historically been designed for thermal comfort alone, which is most efficiently achieved at lower humidity—particularly during winter when the air is driest. Buildings in cold and mixed climates routinely operate at less than 20 percent humidity during the coldest months, which not-surprisingly constitute flu season. A holistic architecture-and-engineering solution is necessary to boost humidity to healthier levels because increasing humidity alone could damage the building envelope. For a fuller explanation, read our white paper.