Each industry has its little secrets. These are the things that those within the industry don’t necessarily lie about, though some do, but are the things that don’t get brought up unless a direct question is asked. Within the often copy-cat HVAC air filter industry there are several things nearly all manufacturers do so there is a vested interest by the industry to discourage consumers from knowing.
Here are the top 5 things HVAC filter manufacturers won’t tell you:
1) Our Filters won’t maintain their particulate removal efficiency
When a filter manufacturer tests the efficiency of one of their products, it is done with a brand-new clean filter; there is no testing of used or partially loaded filters. This seems a bit odd as the majority of the time in service it will be partially loaded with debris. What we’ve found when testing filters throughout their use is if they use synthetic coarse-fiber media the filters lose efficiency as they get loaded with particles. This is echoed in the ASHRAE test method which on page 3 of the filter test standard 52.2–2012 states that filters using synthietic coarse media will show a higher efficiency in the test than will be achieved in actual use. Europe’s counterpart to ASHRAE, Eurovent, also requires a step in testing that simulates a filter being in service prior to testing the particulate removal efficiency of the filter.
2) We Only Care about Innovations That Lower Our Costs
Every so often air filter manufacturers come out with a “new” product or an update to their existing product and declare it the most innovate air filter available. Case in point is the rise of self-supported pleated air filters, which cost half as much or less to make as traditional pleats but are sold at about 15% less to the consumer. Using synthetic coarse-fiber media is also a common cost-saving measure that offers lower dust-holding capacity and shorter life than traditional fine-fibers, but costs 30%-70% less for manufacturers to buy. In both of these instances the unit price of the filter goes down, however you’ll be buying more often. As most of the industry is making self-supported pleats and pushing their synthetic coarse-fiber filters it does seem to be a conspiracy or at least some co-opetition (cooperating competition) to help boost the overall revenue of the industry. After all, if the only options available to consumers are poorly made, cheap products then each manufacturer will have residual benefit. Once in a while a product is released that actually is better than its predecessor, however we mostly see advertisements for it and rarely see them in the field - for reasons we’re not quite sure of.
3) We only care about initial static pressure
Because there is no good test method to tell you how filters perform over time, and in-situ testing done within your own airhandlers can be manipulated, all the focus is on what can be put on brochures. Plus, they usually give themselves a 5–15% margin of error on whatever is published. Filters go through multiple testing and only the very best test report is used to promote the product. They can do this because they know most users will never audit the performance of the filter and will intrinsically trust whatever is on the brochure because of the “oversight” from ASHRAE third-party testing. However, this testing is never audited or certified by ASHRAE and because the manufacturer is paying the “third party” to test there is an underlying want to please the manufacturer so their future testing is done at their facility.
4) Pleated and Panel filters stink, but it’s most of our sales
Most of our customers are surprised to find out that some high-efficiency filters, which catch significantly more particles than the medium-efficiency pleats and panels, consume less energy to move air through them. That’s right - pleats and panels not only don’t filter much - about ½ % (yes one-half of one percent) of particles in the air but they also are huge energy wasters. The problem is these products drive somewhere between 40%-65% of the revenue for most air filter manufacturers. This creates a situation of keeping the status quo of MERV-8 pleat and panel filters as the basis of design for new air handlers even though other styles will use less energy, keep the equipment operating better and cleaner, and last much longer to help ease the strain of Preventive Maintenance programs.
5) Our energy calculators are not even remotely accurate
Everybody wants energy savings; which means every manufacturer wants to be able to show how their products will save energy. The end result is poorly built calculators that really don’t take real-world performance into consideration. With filters, the difficulty is that the static pressure changes over time, or “dust-loading curve” is not linear, which most calculators assume. The calculators also don’t take into consideration the external conditions that vary from building to building. The good news is most people have stopped trusting all of the calculators/life cycle cost projections that manufacturers have created. The difficulty is there are some fantastic Life Cycle Cost software that does a great job - just make sure that the basis for the calculations are from real-world testing, not just some computer formula.
If you keep your eyes open, and ask questions to flush out these five things next time you need HVAC air filters you’ll be ahead of the game and will be more able to buy quality stuff that will perform better than you thought an air filter ever could. As always you can reach-out to us