Maintaining clean air in industrial workplaces isn’t a one-size-fits-all task. Different industries produce different types of particulate matter, meaning their air filtration needs can vary widely. MERV (Minimum Efficiency Reporting Value) ratings are an indispensable tool for all industrial operations to ensure they can function consistently, efficiently, and safely.
Why MERV Ratings Matter in Industrial Air Filtration
A MERV rating is a measure of how effective an air filter is at trapping airborne particles. It’s expressed as a number from 1 to 20, where higher numbers indicate finer particles being trapped. While a filter with a high MERV rating is considered a more effective filter, this doesn’t mean that every application benefits from top MERV ratings for their filtration systems. If the MERV is too high, the filter can restrict airflow in the system and adversely affect its efficiency and durability. For instance, ASHRAE recommends at least MERV 13 for general commercial building HVAC systems, and many industrial environments see optimal results with filters in the MERV 13–15 range. Here are some key sectors in Canada, along with their common filtration concerns and how MERV ratings help businesses select the right filters for them.
Woodworking Shops
Sawdust and Wood Particles
If you manage a woodworking shop, you know how quickly sawdust and other wood debris can fill the air. Airborne particles from woodworking are messy and can pose respiratory hazards and even fire risks. Because wood particles vary in size depending on your operation, MERV ratings are key in helping you find the right filter for your operations.
- Dust size matters: Larger wood debris and visible sawdust particles are easily captured by moderate filters (around MERV 8–11). However, ultra-fine wood dust from sanding can linger in the air and requires a higher-efficiency filter to trap it.
- Shop size matters: Smaller woodworking operations or hobby shops often get by with simple paper filters around MERV 10. They will catch a good portion of dust while keeping costs low. Industrial-scale woodworking facilities, on the other hand, should consider higher efficiency. Heavy-output woodshops should employ filters rated at least MERV 13 to capture fine particulate and protect workers’ lungs. Schools or institutions with wood programs opt for filters rated as high as MERV 16 to meet strict air quality regulations.
- The right filter media matters: Wood dust can clog filters quickly. Look for filters with durable, pleated media (e.g. spun-bond polyester cartridges) that can handle high dust loads and be cleaned or replaced easily. These are commonly in the MERV 10–12 range and outperform basic paper filters by offering better airflow and easier dust release.
Manufacturing Facilities
Dust and Particulate Control
“Manufacturing” is a broad category. It encompasses a massive range of operations, including metal fabrication shops, machinery production, and assembly lines. The air quality challenges vary from business to business, but generally these environments produce nuisance dusts (from processes like grinding, cutting, or material handling) and combustion particles (from forklifts or machinery). Here’s what to consider:
- General dust vs. fine particulate: In standard manufacturing settings without extreme hazards, filters in the MERV 9–12 range will capture a large share of airborne dust.
- Optimal MERV for industry: MERV 13–15 filters are commonly used in Canadian manufacturing facilities, offering a strong balance between fine particle capture and airflow. This range is ideal for most industrial environments and aligns with indoor air quality recommendations, especially in post-pandemic conditions. Higher MERV filters help remove contaminants like metal fumes, welding smoke, and oil mists, thus improving air quality for workers.
- Ideal media for manufacturing: For added performance, Nanofiber FR media is suited to critical environments, while spunbond polyester is a reliable choice for general dust management.
- Airflow is always a factor: Higher MERV filters can restrict airflow if your system isn’t equipped to handle them. Most modern industrial systems in Canada support at least MERV 13; consult a filtration specialist to ensure proper balance between efficiency and airflow.
Welding and Metal Fabrication Shops
Fume and Smoke Extraction
Welding shop operators deal with a uniquely dangerous pollutant: welding fume, which consists of microscopic metal oxide particles and gases. These fumes often contain substances like hexavalent chromium or manganese, making them extremely hazardous. They can easily penetrate deep into the lungs if they are not filtered out. Here’s how to tackle air filtration in welding and metal fabrication environments:
- Use high-performing media: Welding produces extremely fine, harmful fumes, often sub-micron in size. Fab-Tex recommends Nanofiber FR filters rated MERV 15 or higher for their surface filtration and easy pulse cleaning. This technology captures particles on the filter surface, improving performance and protecting worker health.
- Proper system design matters: Use source-capture equipment like fume arms or portable extractors to draw fumes at the arc before air is filtered. Perform regular maintenance to prevent particle buildup and re-entrainment.
- Follow CSA standards: In Canada, shops are required to control welding fumes. Higher MERV filters reduce long-term health risks and help facilities stay compliant.
Never compromise on filtration! Worker safety always comes first.
Pharmaceutical Production and Cleanrooms
- Top-tier MERV ratings: Pharmaceutical production areas often demand filters at the very top of the MERV scale. MERV 17–20 filters are generally reserved for pharmaceutical manufacturers and cleanroom environments. These filters can capture over 99.97% of ultra-fine particles (at or below 0.3 microns). MERV 17–20 overlaps with HEPA-grade performance, even though ASHRAE’s official scale tops out at MERV 16. Pharma facilities must use near-HEPA or HEPA filters to ensure sterile, contaminant-free air.
- Why they’re so high: In pill production, for example, you need to filter out any dust or active ingredient particles to prevent cross-contamination between batches. In sterile pharmaceutical compounding or vaccine production, filtration keeps bacteria, mold spores, and viruses out of the air. Only the highest-efficiency filters give that level of protection. These operations require using filters rated MERV 13A or higher. Often much higher.
- Layered filtration approach: Typically, facilities will use a multi-stage filtration system. One such system may consist of a pre-filter of MERV 8–11 to catch larger dust, followed by a secondary high-MERV filter (13–16), and finally an ultra-high efficiency filter (17–20 or HEPA) for final air polishing. This keeps the costly final filters from clogging too fast and ensures longevity. Maintenance managers should monitor pressure drops across each stage and replace filters as needed to maintain the required air cleanliness class.
Pharma operations in Canada should invest in the best filtration available. It’s about product purity and patient safety. The optimal MERV rating for pharmaceutical environments is at the upper limit of the scale. If you’re at all unsure, be sure to consult an air quality expert.
Food Processing Plants
Keeping It Clean and Compliant
Food and beverage processing facilities share some challenges with pharma in terms of needing clean air to avoid product contamination, but their requirements aren’t quite as extreme. For the food industry, ventilation needs to filter out dust, spores, and other contaminants that could spoil products or violate health standards, such as CFIA or Health Canada. Consider the following:
- Common particulates: Food processing creates fine organic dust—think flour, sugar, spices, and grains—typically between 1 and 10 microns range. Filters rated MERV 11 or 12 can capture up to 85% of particles in the 1–3 micron range, significantly reducing airborne dust.
- Added protection as needed: Many facilities, especially those with open product areas, use MERV 13–14 filters to capture mold spores and bacteria. This level of filtration supports safer operations and aligns with audit standards promoting MERV 13+ for food plant air quality.
- Avoiding unintentional seasoning: Good air filtration ensures that dust from one process (say, milk powder) doesn’t settle in another area (like where you’re packaging products labeled dairy-free) while keeping your equipment cleaner. By using the right MERV filters, you’re preventing “ghost flavours” and potential allergens from contaminating products via the air.
- Schedule regular filter changes: In a food plant, filters can load up quickly due to the high volume of particulate. A clogged filter can harbour moisture and microbial growth, the exact opposite of what you want to accomplish. Keep those filters fresh!
Industrial air filtration for Canada’s food sector must also account for our climate. Wide temperature swings and humidity can affect filter performance. Choose robust filters rated for your environment, and you’ll maintain both air quality and product quality.
Powder Coating and Paint Booths
Capturing Overspray and Fine Powders
Operations like powder coating, spray painting, and paint booths create lots of airborne particulate in the form of overspray. In powder coating specifically, finely ground pigment/resin powder is sprayed onto parts and then baked on. The overspray that doesn’t stick needs to be filtered out of the air – both to keep the shop clean and to recycle unused powder. Here’s how MERV fits in:
- Particle characteristics: Powder paint particles are generally larger than welding fume but smaller than, say, wood chips. They might range roughly from 5 to 50 microns in size. Because they’re relatively large, you don’t necessarily need ultra-high filtration to catch them. A MERV 10 filter media using a cellulose/poly blend is sufficient to grab most powder particles and is commonly used for powder paint dust collection.
- Know when to use higher MERV: If your process produces exceptionally fine powders, or you have to meet strict emission standards (some Canadian provinces regulate air emissions from industrial paint operations), you might go up to MERV 13–15 on your final filters. Higher MERV filters will ensure that even the smallest powder or paint pigment particles are not vented out or recirculated. This can be important in facilities that operate near office areas or in urban locations where neighbours won’t appreciate pigment dust escaping. High-MERV filters also keep the painting environment cleaner, leading to better finish quality – no dust nibs in your paint job!
- Maintain airflow for safety: Paint booths and coating lines require a certain airflow to keep flammable vapours from accumulating. Oversized high-MERV filters can impede that airflow if not matched well. So, ensure any filter upgrade is vetted – many powder systems use multiple filters to increase surface area (which allows high efficiency without choking airflow). Regularly inspect and replace filters because as they load up with powder, they not only reduce ventilation but could also become a fire hazard if the powder is flammable. A clean filter equals a safe and efficient paint booth.
The best MERV rating for your powder coating application will capture your overspray without stifling your exhaust. Many shops find success with MERV 10–13 filters and use filter media coatings like Teflon that let powder release during pulse cleaning and keep performance high.
Get the right air filtration solution for your operation
Every industry and facility is a little different. Factors like the volume of contaminants, specific health regulations, and HVAC or dust collection system design vary from facility to facility. The ideal MERV rating between two woodworking shops or two food factories can even be different. That’s why developing a custom, application-specific solution is what your facility needs.
Fab-Tex specializes in industrial air filtration across Canada. Our team can assess your system requirements and recommend the right solution, including custom sizes and specialty media. We’ll help you balance filtration efficiency, airflow, and maintenance to ensure reliable performance and long-term value. Don’t let the complexities of MERV ratings trip you up! Contact Fab-Tex today and get the right filtration system for your business.