How We Verify Prices and Specs

Our Verification Process

1. One Price Source: Filters Fast

Our crawler fetches prices from Filters Fast only: its size listings (Filters Fast brand MERV 8/11/13, sold in 6-packs for 1-inch and 3-packs for 4-inch) and its product pages for genuine Aprilaire 410, 413 and 416 filters. It identifies itself honestly, waits several seconds between requests, and follows Filters Fast's robots.txt.

We also link to Nordic Pure size pages, Filter King MERV, custom-size and auto-delivery pages, and, on the Aprilaire 413 page, to Aprilaire, Amazon and Home Depot. We don't crawl those sites, so we never show a price for them. They are "check current price" links only.

2. Timestamped Crawls

Every price includes the crawl date (current: 2026-10-07). The date only moves when every product gets a fresh price in the same crawl. If any product fails, the whole crawl is discarded. Prices may change after the crawl date. Always click through to the source link to see today's price before purchasing.

3. Public listings, no hidden markup

Prices shown on this site are the public Filters Fast listed prices for the pack size shown. Per-filter figures are the pack price divided by the pack size. We do not add markup. If a purchase made through an outbound link on this site earns a commission, an FTC disclosure is on the page. Prices shown are still the public list prices.

4. Pressure Drop Data

Pressure drop (measured in inches water gauge, w.g.) comes from OEM-published specs when available. If a manufacturer hasn't published it publicly, we mark it "Unknown" — we never estimate or invent pressure-drop figures.

Example: Filterbuy publishes pressure-drop ranges for MERV 8/11/13 on their 16x25x1 page. Aprilaire does not publish pressure drop for the 413 on public product pages, so we mark it "Unknown."

5. Actual vs Nominal Size

Nominal size is the slot dimension (16x25x1). Actual size is the physical filter measurement (15.75x24.75x0.75). Manufacturers print actual dimensions on their spec sheets. We show both. Always buy by nominal size (the printed label on your old filter).

6. No Fake Reviews or Tests

We do not run "lab tests" or publish fake user reviews. We compare published specs (MERV rating, pressure drop, dimensions) and real prices. If a filter performs poorly in the field, that's outside our scope — we're a size finder and price table, not a testing lab.

7. No Urgency Tactics

We don't use fake urgency ("Only 3 left!"), fake scarcity, or fake stock counters. The "In Stock" column reflects the source page's stock status at crawl time. Check the source link for current availability.

8. Mike Moore, Operator & Author

This site is operated by Mike Moore, a solo operator building an unsponsored HVAC filter price table. No corporate backing, no fake author personas, no "testing team." Just one person, public data, and a crawl script. See the About page for more.

What We Don't Do

• No invented specs: If we don't have OEM data, we mark it "Unknown."
• No fake reviews: We don't publish user testimonials or fabricated product reviews.
• No affiliate markup: Prices are from public listings. No hidden fees.
• No urgency tactics: No "Only 2 left!" or fake countdown timers.
• No stock manipulation: We show source stock status at crawl time; always verify on the source page.
• No fake testing: We don't run "lab tests" or claim to test filters in-house.

Questions?

If you spot a price discrepancy, an incorrect spec, or a broken link, contact Mike Moore via the About page. We'll verify and update the table on the next crawl.