Purolator Air Filters FAQ
What is your shipping policy?
We offer flat-rate shipping for $15 on all orders.
While we strive for timely delivery, shipping times are estimates and may vary. An estimated delivery date will be provided when you place your order, but actual delivery times may differ slightly depending on various factors.
For more information, contact our customer service team or call 866-455-2128.
What is your return policy?
We accept returns of resalable items within 60 days of purchase. To return an item:
• Contact our Customer Care Team for a Return Merchandise Authorization (RMA).
• Ship the item back within 30 days of receiving the RMA.
• Return the product in its original packaging, unopened and undamaged.
Please note:
• A 25% restocking fee may apply.
• Custom or non-stock items are generally not returnable.
• Returned items must be in full cartons.
• For full details and exceptions, see our complete Return Policy.
What filter products does Purolator offer?
Purolator manufactures a full range of air filters for residential, commercial, and industrial applications:
- F312 Fiberglass Panel Filters — Disposable, high-velocity prefilter ideal for commercial and industrial environments with heavy dust and lint loads. UL Class 2 rated.
- P312 Synthetic Panel Filters — Polyester media for residential, commercial, and light industrial use. A direct replacement option for F312 fiberglass filters.
- Pleated Filters — MERV 8–11 options for improved particle capture in residential and commercial HVAC systems.
- Mark 80-D — A higher-efficiency MERV 8 pleated filter recommended for allergy and asthma sufferers.
Custom sizes are available. Call 866-455-2128 for a quote.
What is the difference between nominal and actual filter size?
A filter is often identified by its nominal size — the actual dimensions rounded up to the nearest inch to make filters easier to find and compare. The actual size refers to the filter's exact measurements, which are typically slightly smaller.
Two filters with the same nominal size may not share the same actual dimensions — this can vary by manufacturer or model. The industry tolerance for these variances is +/- 1/8" for both width and length.
If your installation has tight tolerances, always confirm actual dimensions before ordering. Call 866-455-2128 if you need help confirming the right size.
Do you offer custom filter sizes?
Yes. Custom filter sizes are available for residential, commercial, and industrial applications. Call 866-455-2128 or contact our team online to request a quote.
Who manufactures Purolator air filters?
Purolator air filters are manufactured by CLARCOR Air Filtration Products, Inc. — a company with over 50 years dedicated to improving air filtration solutions and one of the most recognized brands in the HVAC industry.
Purolator filters are carried by Air Cleaning Specialists (ACS), which has specialized in indoor air quality since 1979. ACS engineers exhaust systems, dust collectors, air scrubbers, and odor, smoke, and fume removal equipment for commercial and industrial customers nationwide.
What are the basics of home air filters?
Your home filter — also called a furnace filter — keeps the coils and heat exchangers on your HVAC system clean, extending its life and improving your indoor air quality.
The most important thing is to change filters regularly. As a general guideline:
- 1" filters: every month
- 2" filters: every 1–2 months
- 4–5" filters: every 3–6 months
Fiberglass filters (sometimes called "throwaway" or "hog hair" filters) are designed only to meet minimum equipment protection requirements. NAFA (National Air Filtration Association) no longer recommends anything under a MERV 7 filter for home HVAC systems.
Pleated filters offer better protection against dust and airborne particulate by folding more filtration media into the same frame depth.
How do I figure out what size air filter I need?
- Check your current filter: The size is usually printed on the filter's frame.
- Measure the return vent: If there's no filter present, measure the length and width of the return air vent opening.
- Check for multiple sizes: Homes often have 2–3 different filter sizes — check each return air vent.
- Measure precisely: Accurate measurements prevent air leakage and ensure proper filtration.
If you're unsure or have an unusual size, contact our customer service team or call 866-455-2128.
When should I change my furnace / residential air filter?
For most residential HVAC systems, change your air filter every 60–90 days. This can vary based on several factors:
Filter type: Fiberglass filters may need more frequent changes than pleated filters.
Home environment: Pets, smoking, or high dust levels may require more frequent changes.
HVAC usage: Running your system more often means replacing filters more frequently.
Allergies or respiratory issues: More frequent changes improve air quality for sensitive occupants.
Filter efficiency: Higher MERV-rated filters trap more particles and may load faster.
Visible dirt: If you can see dirt on the filter, replace it regardless of time elapsed.
As a general rule, check your filter monthly and replace it when it appears dirty. Consult our team of specialists or refer to your system's manual for more detailed guidance.
What factors affect air filter performance in residential HVAC systems?
All filters — commercial or residential — must balance three forces:
- Resistance to airflow
- Dust-holding capacity
- Particle removal efficiency
Residential systems present two main constraints. First, filter depth: most homes have only a 1-inch slot for a filter. Second, blower horsepower: residential units typically have a 1/4 or 1/3 HP blower, with only about 0.1 inches of water gauge pressure allocated for the filter. These constraints limit filter choices without retrofitting.
The main 1-inch options are:
- Standard Fiberglass Throwaway Filter — Low efficiency, very low resistance. Designed to remove only larger particles and protect the air handler.
- Pleated Filters — Higher efficiency by folding media into a 1-inch frame, without excessive pressure drop.
- Other media types — Metals, plastics, cellulose, electronic filters, etc.
Higher-efficiency filters (typically MERV 11 and above) may cause low airflow problems in some residential systems. The higher the MERV number, the higher the efficiency — but always verify compatibility with your HVAC system first.
What is the MERV rating system?
MERV (Minimum Efficiency Reporting Value) is a filter rating system developed by ASHRAE to standardize and simplify filter efficiency ratings. The higher the MERV rating, the higher the efficiency — a MERV 12 filter removes smaller particles than a MERV 8. This also allows you to compare filters across brands: any MERV 8 filter will perform similarly to any other MERV 8 filter in terms of efficiency.
- MERV 1–4: Particles 10+ microns. Minimum residential, light commercial, and equipment protection.
- MERV 5–8: 3–10 micron particles. Industrial, commercial, high-end residential, paint booths.
- MERV 9–12: 1–3 micron particles. High-end residences, upgraded industrial workplaces, commercial boilers.
- MERV 13–16: 0.3–1 micron particles. Hospitals, healthcare, high-end commercial, telecommunications manufacturing.
For allergy or asthma concerns, we recommend a minimum of a MERV 8 filter.
What's the difference between MERV 8, MERV 11, and MERV 13 filters?
MERV 8 Filters:
• Suitable for most residential uses
• Capture 70–85% of particles sized 3–10 microns
• Filter out dust mites, mold spores, and pollen
• Good balance of filtration and airflow for older HVAC systems
MERV 11 Filters:
• Better filtration than MERV 8
• Capture 85–95% of particles sized 3–10 microns
• Also filter pet dander and auto emissions
• Beneficial for households with allergy or asthma sufferers
MERV 13 Filters:
• Highest filtration of the three
• Capture >90% of particles sized 3–10 microns and 75–90% of particles 1–3 microns
• Can filter bacteria and smoke particles
• Best for homes in poor air quality areas or those with severe allergies
Higher MERV ratings increase airflow resistance. Verify your HVAC system is compatible with MERV 13 before use, as they can strain some systems. For most households, MERV 8 works well.
Can I use furnace filters as air cleaners for my whole house?
Modern pleated furnace filters have improved significantly and can do more than protect your HVAC equipment. Two advances drove this: the adoption of a pleated structure (which reduces media velocity for better efficiency at lower pressure drop) and the development of specialty media types (such as tribo-charged and electret media) with higher initial efficiency at relatively low pressure drops.
When selected and used properly, pleated furnace filters can significantly reduce indoor air pollutants — including alleviating allergy symptoms such as sneezing, watering eyes, and postnasal drip during pollen season, and slowing the settling of dust and respirable particles in the home.
Why is air filtration important?
Air filtration is essential to maintaining healthy, safe indoor environments — from preventing lint from clogging HVAC coils to removing particles as small as 0.1 microns. Air filters serve many purposes, including:
- Protecting the health and wellbeing of building occupants
- Removing staining particles that discolor interior surfaces and decor
- Reducing maintenance frequency on blinds, fluorescent bulbs, and ductwork
- Protecting valuable contents such as artwork, tapestries, and items of historic significance
- Eliminating fire hazards by removing lint and combustible debris from ductwork
- Extending shelf life of perishable products by removing airborne mold in processing environments
- Removing airborne bacteria from operating rooms to help prevent postoperative infection
