HVAC systems are essential for bringing conditioned outside air into a building and recirculating air for its occupants. Commercial HVAC systems can filter out contaminants like allergens and airborne viruses, as well as harmful PM2.5 and PM1 particles. Additionally, they remove particles that could potentially damage air handling units. However, not all air filtration systems perform well. Retrofitting your commercial HVAC system with adequate planning can significantly improve energy efficiency, reduce costs, and enhance indoor air quality.
This article will answer the following questions as well as other questions:
- How much cleaner can the air be after retrofitting a commercial HVAC system?
- How can improving my current HVAC design save more energy?
- How can improving the design save costs in other areas?
- How difficult and costly is it to improve my commercial HVAC system?
The benefits of retrofitting your commercial HVAC system
What is the extent of air quality improvement achievable after retrofitting or upgrading?
The potential for improving air quality is only limited by the available budget. If you are willing to invest in new fans, blowers, and other equipment, you can achieve cleanroom levels of air quality. However, installing HEPA or ULPA filters throughout a building would require revamping the entire system, which is very uncommon and depending on building size, could be quite costly.
For most commercial applications, a minimum of a MERV 13-A final filter is recommended for basic operation. For added protection of commercial building occupants, a MERV 14-A rated filter can be beneficial. Opting for a much higher MERV efficiency filter may result in increased pressure drop and a possible decrease in airflow.
How much impact can you have in terms of protecting both occupant health and HVAC equipment?
Usually, a MERV 13-A filter will provide clean air and protect both the building occupants and HVAC equipment. Higher efficiency filters may be desired in more sensitive areas such as meeting rooms or production areas. Building owners, companies, and employees can negotiate on what is necessary to maintain a clean area for internal commercial processes, and a healthy environment in the workplace.
How can enhancing my current HVAC system design in a commercial setting lead to greater energy savings?
Many filtration systems are designed for two-stage filtration, consisting of a prefilter and a final filter, each with its own pressure drop rating. The combined pressure drops of the two stages determine the overall resistance to airflow of the system. For example, if both the prefilter and final filter have a pressure drop of 0.5, the system runs at a one-inch pressure drop. Overall efficiency of the system is determined by the final filter. This means that even if you have a MERV 8 prefilter and a MERV 14 final filter, particle capture efficiency does not increase above MERV 14 because it is not additive, the system’s efficiency will still be MERV 14, the MERV rating of the final filter.
To improve efficiency and save energy, you can upgrade from a two-stage MERV 14 system to a single-stage MERV 14 system, effectively reducing the pressure drop, especially in systems with variable frequency drive (VFD) controlled fans.
A standard level of filter efficiency for good air quality is considered to be a minimum of MERV 13-A. To enhance efficiency, you can upgrade from a pleated MERV 8 and MERV 13 bag filter combination to a single HighFlo® ES MERV 14 filter. This upgrade in the unit will increase efficiency by one MERV rating while reducing pressure drop by 50%.
The transition from a two-stage filtration system to a single-stage HighFlo ES system is either cost-neutral if the filters being replaced total the same cost, or possibly less expensive. Read more on the total cost of ownership (TCO) of air filters
In what ways can improving an HVAC design result in cost savings in other areas?
Further cost savings can be achieved because the coils and ducts do not have to be cleaned as often. The motor will last longer as it runs with less pressure, and there will be less cleaning needed in the building. Additionally, employees will likely require fewer sick days, and increased productivity could be achieved due to better health resulting from better indoor air quality.
How challenging and costly is it to enhance or revamp my commercial HVAC system?
It depends on the current system design. With a walk-in air handler, in larger office buildings, it’s usually a fairly simple upgrade. A walk-in handler normally has a track for the prefilters and the final filters. Changing the filters is as simple as sliding a different filter onto the track.
If you have a system where the prefilters and final filters are in separate holding frames or tracks, it can be a little more difficult because filtration is required for the coils in the front. If you want to switch to a single-stage filtration system, it requires fitting a 12-inch, 15-inch, or 21-inch bag filter in the front area that may have only been holding a 2-inch filter. If you have space from the dampers to the coils and if you have enough room for a minimum of 12 inches, then it only involves installing a track or new framing system and simply installing the new filter in front.
It takes about a full day of retrofitting per unit to make the changes required. Which is not very expensive taking into account the overall operating costs of a building. Also, cost savings can be realized over 5 years even after accounting for the retrofitting costs.
What are the common issues with outdated or inefficient air filter designs, especially In Canadian climates with extreme weather, and how can they be addressed?
When it comes to the efficiency of filter design, it’s important to consider a few different factors. If a filter has a low MERV rating and collects less dust, it can lead to problems downstream in the HVAC system, affecting the coils as well as other equipment, and the comfort of the building occupants. Inefficient design, such as using cheap materials like cardboard frames or thin wire backing can cause the filter to blow out, creating a bypass in the system and allowing particles to go downstream. This is particularly problematic in Canadian climates during winter, when snow can be pulled into the HVAC system. In such cases, it’s not just a filter issue, but a design issue that requires changes to the air handler to reduce air velocity and prevent snow from entering the system.
Preventing snow from entering the HVAC system can be achieved by reducing the intake velocity by means of building a larger cover. This causes the snow to fall in front of the air handler instead of getting sucked in. Another option is to relocate the filters further away from the intake, allowing the snow to come in without clogging the filters. During the summer, it’s best to plan for emergencies by leaving space for carbon filters which handle smoke , especially with the increase in hot weather which has led to conditions that increase the likelihood of wildfires. This preparation can also help avoid damage to the HVAC system or scrambling for last-minute adaptations.
What are the cost-saving benefits of green-retrofitting your commercial HVAC system?
The most important aspect of an environmentally-friendly HVAC system design is energy conservation. Generating some forms of energy causes pollution and increases your commercial carbon footprint. In areas that don’t rely on hydroelectricity, solar, or wind power, high-carbon emitting, fossil fuel-based energy sources like oil and natural gas are used. Therefore, using a filter system that operates at a lower pressure drop can reduce overall energy usage and reduce your carbon footprint.
Understanding the Need for System Design/Retrofitting – Why redesign your commercial HVAC system?
What are the long term benefits of retrofitting your commercial HVAC system?
Retrofitting your commercial HVAC system can reduce waste and has a positive environmental impact. By throwing away fewer filters, you can significantly decrease the amount of waste going into landfills. Looking at the long-term perspective, if you’re currently disposing of an average of 10 filters every week, the cumulative impact over five or ten years for 100 buildings is substantial in terms of the amount of waste generated as well as the associated costs, such as hiring extra contractors for change-outs, system maintenance, and waste disposal.
What steps need to be taken to improve your current commercial HVAC system?
There are two types of filter installation hardware designs in air handling systems: front-access and side-access systems. Front access involves accessing the front of the filter and pulling it out of a frame; side access involves sliding it down a track.
For a side access system, there is usually a one-inch, two-inch, or four-inch track holding the filter. It is possible to upgrade to a higher efficiency filter or a lower pressure drop filter simply by sliding a new filter down the same track without any retrofitting.
For front-access systems in a holding frame, you typically won’t have to do any hardware modifications because most frames are universal and can hold any type of filter. In this case, simply change the clips and install the new filter.
Most air filters come in the standard size of 24” x 24”. If you would like to switch to a bag filter which can go up to 36 inches deep, ensure that you have a 36-inch clearance. If you currently have 12 inches of space, you can switch to a box filter, such as Durafil® or Aeropac®, depending on your needs.
Why is it important to have a professional assessment and planning for a commercial HVAC retrofit?
Most people don’t take note of the difference in pressure drop when selecting air filters. Installing the wrong filter can significantly reduce airflow within a building when pressure drop is too high. It is best to choose a filter with the lowest average pressure drop during its lifetime.
An air quality expert can assess your current system: they start with a thorough evaluation of your existing HVAC system, identifying areas where performance is lacking, such as inconsistent temperatures within occupied areas, high energy consumption, or frequent maintenance issues. After identifying problem areas, an expert can provide you with custom solutions to fit your goals and can advise you on how to save costs.
Over five years, how much energy can you save by retrofitting your commercial HVAC system?
Switching from a filter with a high pressure drop to a filter with a low pressure drop can potentially save a company tens of thousands of dollars in energy costs. There are downstream benefits as well, such as keeping coils, fans, diffusers, and ducts clean, reducing the need for maintenance and equipment replacement in the HVAC system.
The savings depend on the current condition compared to the future state. For example, if you switch from using one type of filter to another that has a similar pressure drop, you may not save energy, but you might extend air filter life.
With a mostly clean source of energy, how else can carbon emissions be reduced?
If an air filter media manufacturer makes air filter media that needs to be replaced frequently, it is important to be aware of the fact that such a process is very costly and dirty. For example, fiberglass media consumes a lot of energy because it involves melting glass using high heat. By making air filters that require less material and last longer, air filter manufacturers can reduce the energy required to make the media thus reducing the amount of carbon emitted. Purchasing half of the filter media from the media manufacturer amounts to reducing energy consumption by half.
What are the benefits of not following a predetermined air filter change-out schedule?
Air filters should be changed based on their type of commercial application and its environment, not just according to generic guidelines. A good prefilter can last four to six months or even up to a year, so replacing it every three months may lead to unnecessary waste and higher costs.
Why is it important to get BOMA, LEED, or other building accreditation?
Most companies choose to get BOMA, LEED, or other accreditation to achieve their sustainability objectives and to attract better tenants for buildings. As a result, buildings are usually better maintained, employees are healthier and happier, and it has a positive impact on other aspects of the building.
- Building certifications such as LEED, WELL, and BOMA accreditation are valuable to commercial tenants because they enhance the building’s reputation, which can be beneficial for public relations
- The primary goal of certifications like LEED, WELL, and BOMA is to improve the internal environment for employees, benefit the environment, and promote sustainability
- It’s important to prioritize the well-being of building occupants and the environment, regardless of whether it’s associated with earning certification points
Camfil’s advanced HVAC filter housing and frame solutions
Part of Camfil’s overall philosophy is to promote premium products. These products are engineered to have the longest lifespan and the best sustained capture efficiency. For instance, a premium MERV 14 filter is guaranteed to maintain its efficiency throughout its lifespan. A great benefit of premium filter design is longevity and fewer replacements needed bringing along cost savings in the long run.
For frames that you want integrated in your system, use a Type 8 frame or FastFrame. For applications where complete retrofit is required, use a Glide Pack.
FastFrame® is the easiest system to use due to its front access, which does not require any clips. However, it’s worth noting that FastFrame does not accept box filters without headers.
The Type 8 frame® has clips but is completely universal.
A Glide Pack® will take precedence over and replace any existing housing. It should be installed in front of the air handling system.
Camfil Type 8 Frame®:
- An air filter holding frame made of 16-gauge welded galvanized steel.
- Allows installation of various combinations of HVAC prefiltration and final filtration.
- Compatible with different filter depths (1″, 2″, 4″, 6″, or 12″).
- Features a ¾-inch filter sealing flange for proper filter seating and sealing.
- Includes filter centering dimples for easy installation and alignment.
- Equipped with polyurethane gasketing for leak-free performance.
- Pre-drilled holes for riveting or bolt-together installation.
- Can be assembled in banks up to six units high.
- Suitable for applications to remove water or oil mist.
- May be configured in a V-bank setup to reduce filter face velocity
FastFrame®:
- Specifically designed for built-up bank HVAC systems.
- Unique compression tab design eliminates the need for fasteners.
- Allows convenient and simple filter replacement without compromising filter seal integrity or indoor air quality.
The Camfil GlidePack® is an air filter housing designed for installation in HVAC ductwork systems. It comes in three different sizes: 13″, 21″, and 32″ depths.
To find out more about how to best retrofit your commercial HVAC system, or get a complimentary IAQ and air filtration site survey, please use this contact form.
About Camfil Canada Clean Air Solutions
For more than 60 years, Camfil has been helping people breathe cleaner air. As a leading manufacturer of premium clean air solutions, we provide commercial and industrial systems for air filtration and air pollution control that improve worker and equipment productivity, minimize energy use, and benefit human health and the environment. Read more about Camfil Canada
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Media Contact:
Phillip Ilijevski
Camfil Canada Inc.
T: 437-929-1161