Here is some feedback on Martin Holladay’s January 2, 2026 blog site “Removing Particulates from Indoor Air”.
The State of California preserves an online totally free search database of a wide range of “appliances” consisting of a/c air filters, here https://cacertappliances.energy.ca.gov/Pages/ApplianceSearch.aspx. I consistently buy the 20 ″ x 20 ″ x 1 ″ Filtrete 2500 (MERV 14) from Costco, presently $52 for a 4-pack or $13 each (but I wait for a sale), so, as an example, anyone can search by “Device Type”=’Air Filters’, or by “Brand name”=’Filtrete’, or by “Design Number”=’2500′. Drill into the preferred filter record to get in-depth performance data, which for this model is based upon a 20 ″ x 25 ″ x 1 ″ filter, using the test treatment from ANSI/ASHRAE Standard 52.2 from 2017. The “resistance” in “inches water column” is determined at 5 “air flow rates” in “cubic feet per minute”, as follows: (515 cfm, 0.10 ″); (770 cfm, 0.17 ″); (1025 cfm, 0.25 ″); (1280 cfm, 0.35 ″); (1735 cfm, 0.53 ″); This filter’s information was added to the database on 7/1/2024 so appears reasonably existing.
While I have only check out the free part of the entitled blog therefore might be misinformed regarding its full material, in my opinion you can better inform your readers, examples as follows:
a) the caption under the opening image states “The greater a filter’s MERV rating, the higher the drop in fixed pressure.” This is unclear, can easily misguide, and is a bit reckless repetition of the “pseudo information” found on the majority of heating and coolings contrator web sites. A better declaration might be along the lines of “filters with up to MERV 14 are readily available with pressure drops within the suggested (xx? 0.25?) inches of water column max limitation, however pressure drops even for the very same MERV differ extensively from one filter make/model to the next, so confirm your favored item’s measured performance utilizing the database link offered below”.
b) the caption under the opening image states “Making up for this pressure drop needs an increase in fan energy.” This is so doing not have in specific info as to be worthless and/or misleading. Walking up the stairs requires a boost in energy used up– so what! You might simply as well state “Keeping the filter slot empty decreases the fan energy consumed by your system.” The reader wants cleaner air, and the informaton must help them stabilize contending aspects to attain an affordable solution. Some readers will want to pay an additional 2 cents (you inform us how much?) monthly in electrical power bills to breathe cleaner air.
c) the caption under the opening image says “… see the Great Homebuilding short article “Clarify.”” The Fine Homebuilding post has its own drawbacks. For instance, in talking about HEPA for eliminating those unsafe (to lungs) 0.3 to 1 micron particles, it makes the blanket declaration “… they are too limiting to handle a heating and cooling system’s complete air flow, so in order to use a HEPA filter in central ductwork, you’ll require a “bypass HEPA” style …” and “… Bypass HEPA styles divert a portion of the airstream, while the rest goes through the less limiting primary filter. Just a fraction of the system’s overall circulation goes through the filter at any time, but over several hours the majority of the air in your home passes through at least as soon as …”. Once again, this seems too simple to me and the market can do much better. A former home of mine in Arizona had the HVAC in the attic, with a lot of room for a folded filter holder with ductwork to deal with say 3 HEPA filters, hence decreasing the net filter resistance by greatly increasing the net filter surface. I see this technique online for healthcare, and so on where the industry standard needs HEPA. Regarding the “bypass” style, does this in fact achieve any much better filtration than using (for instance) the Filtrete 2500, which per the above connected database has 75% filtering efficiency for the 0.3 to 1 micron particle size? What about running the fan all the time, or as the “circ” mode of my thermostat permits, at ~ 25% of the time? Does this carry out also or better than the HEPA bypass design?
When thinking of and using platitudes based upon factor to consider or presumptions of energy expense and energy generation contamination, please stop for a minute and think about: what if the United States energy market converts to full renewables, especially solar, with enormous (newly) expense efficient utility size sodium batteries, making electrical energy less contaminating and hopefully less costly?
Where I survive on the Olympic Peninsula in Washington state, our limited electrical energy presently costs $0.0817 per kilowatt-hour, before repaired service fee and different taxes/fees. 78% is from hydro, and 11% from nuclear, leaving just ~ 11% from possibly more contaminating sources.
And now, just dreaming: with regard to the cumulative United States housing market actually attaining high quality with regard to all elements of a home, my last thoughts for the entire Green Building Consultant neighborhood, is, that the neighborhood of specialists would do so better to create and define in complete and agonizing information basic homes, with some methods for a buyer to purchase an actual home constructed and validated to those specs, in their desired area. Marketing people might survey the population to recognize say 5 to 10 desireable single and two-story floorplans. The whole GBA thing, when looked at from a range, is a continuous churn of realities, opinions, and so on, over thousands of structure system components/details, with widely varying approaches per climate, home builder choice, etc regarding be mind boggling. OK, yes, assists the highest experienced practitioners deal with particular concerns, however otherwise, uncertain how much this is moving the real estate industry forward.
Finest concerns, and thank you Martin for all your contributions to this crucial body of understanding.