The coronavirus hit the United States abruptly in March of 2020 and sent the country into a tailspin. Now, the country is in the healing process from the initial breakout– but with the healing process, there are quite a few things to consider. The virus is still out there, and facility managers need to respond to the threat of an airborne virus. Many places have outdated heating, ventilation, and air conditioning (HVAC) systems that are not necessarily equipped to reduce the risk of airborne transmission for viruses such as COVID-19. With this unique concern, this article aims to highlight ways a HVAC system can be improved.
Key Issues for HVAC Systems
You want to consider which issues you can come across when retrofitting an HVAC system. Many HVAC systems were built for ventilation and the least cost; now, building owners and facility operation managers will need to consider the healthiest, most efficient system. Here are a few issues that occur in an HVAC system:
- Air Dilution – a combination of air and flue gases that lower emission concentration. This can negatively impact an indoor environment and occurs with increased ventilation, which is actually favorable in the post-COVID world. Weather is a huge factor to consider for air dilution, as harsh climates cause the system to work harder; one thing to consider is the system’s functionality and being able to program it for the most efficient operative system.
- Filtration – HVAC filters are designed to reduce indoor air pollution, but they do not necessarily remove all pollutants from the air. The small particulates in the air that could carry coronavirus will need to be combated with MERV 13 filters. MERV 13 is the recommended filter by the US Department of Energy, and this type of filter should block 99% of bacteria and virus-carrying airborne particulates. The following is the rating criteria for a MERV 13 filter:
- The filter will trap less than 75% of the average particle size 0.3-1.0 Micron
- The filter will trap 90% or better of the average particle size 1.0-3.0 Micron
- The filter will trap 90% or better of the average particle size 3.0-10.0 Micron
- An example of what the filter will trap includes: Bacteria, most tobacco smoke, droplet Nuclei (i.e., sneeze).
The recommended filter is thicker and denser, meaning that to pass air through the filter, the HVAC system will need to work harder. Additionally, most systems have the filters they can handle, and replacing the filters can lead to more frequent maintenance, decreased efficiency, and failure of the system. Overall, this can lead to a cost increase for the energy source of the building. To avoid costs that could affect the system, it is best to engage experts when seeking to retrofit the system. Design Everest is a great source of information and has reliable engineers that can help look for the best way to retrofit the system and achieve an optimal cost.
- Humidity – the amount of water vapor in the air. Indoor humidity is a factor to consider in HVAC installation and retrofitting. Comfort levels for humidity to the average person can range from 40%-60%, and most air conditioning systems aim to reduce humidity by removing moisture from the air circulating in the building. Public Health officials have observed that viral particles remain airborne in dryer air. Alternatively, too much humidity can create mold problems and promote other issues, so we then ask what the ideal humidity level is indoors? The ideal range is 40%-60% relative humidity, where relative humidity is the actual amount of water vapor in the air divided by the amount of water the air can hold at the current temperature. This can be monitored in the HVAC’s control system. When retrofitting a system, you may need to update the building control sequence or upgrade the system by installing a separate humidifier or dehumidifier.
All of these issues to consider when improving your HVAC system are all based on the best option for the building. Anytime you retrofit the existing system to adapt to the health factors of the post-COVID world, it is best to go with the improvements that will meet the budget and provide the functionality intended by the upgrade. Additionally, there are modern ways to improve a system that can be a better fit.
Modern HVAC Innovations
There are some modern approaches to providing a high-performance HVAC system that are worth looking into. Part of improving buildings in the post-COVID era will be researching and familiarizing oneself with the innovations that are out there. Let’s take a look at some of the available options:
- UV Filtration – use of ultraviolet light as opposed to a physical filtration barrier within the HVAC system. For retrofitting a system that cannot accommodate large new filters, UV is a cost-effective way to modernize the system. UV light can kill mold within the bulb’s line of sight. These are some specific types to consider:
- Coil Sterilization – This uses horizontal lights installed in the return air ducts and sterilizes the air handler coil. Coil Sterilization runs on a 24/7 schedule and would be considered the most common type of UV Filtration.
- Air Sterilization – This type of UV system uses the light unit to sterilize moving air. The light unit is installed in the return air duct and runs on a cycle with the air handler blower.
UV Filtration and filters, earlier discussed in the article, can be used in a combination method to find the best solution that works to retrofit a building’s HVAC system.
To recap the article, factors such as dilution, filtration, and humidity are to be considered when seeking to improve a building’s HVAC system post-COVID. Design Everest can work with you to understand the existing system and the needs of the building. At Design Everest, there are professionals familiar and skilled in retrofitting existing systems that can assist in making the process possible for you. With knowledge of building plans, DE will be able to evaluate the options available to improve the HVAC. Call (877) 959-5914 to get a free quote and consultation today.