Home › Models › Bionaire BCM-646
What filter does a Bionaire BCM-646 take?
It takes the Holmes HWF100 Filter (Type E) — OEM part number HWF100.
Bionaire BCM-646, evaporative humidifier, tabletop.
Lowest verified price: $29.95 — aftermarket, 6-pack ($4.99 per filter) at DiscountFilters. Free shipping on orders $70+ at DiscountFilters; a fee applies below that. Checked 2026-11-11.
Buy the HWF100 on Amazon — HWF100Amazon search for the exact part number (no single listing is endorsed). Amazon price is shown on Amazon; we do not quote it here.
The part, in brief
| Part | Holmes HWF100 Filter (Type E) |
|---|---|
| Replacement interval | Replace every 1–2 months in season (general Holmes wick guidance). |
| Per change | Filter count per change varies by model: HM6000/HM6005/HM7203 take 2; HM7305/HM7306 take 3; HM7405 takes 4; HM4600 takes 6 (DiscountFilters / HM4600 manual). |
| Equivalents | BestAir H100, DiscountFilters (AIRx) HWF100 replacement, Bionaire BWF-100, Sunbeam SWF-100, Accumulair UFHWF100 |
Verified prices
| Option | Price | Store & shipping |
|---|---|---|
| Aftermarket 6-pack ($4.99 per filter) | $29.95 | DiscountFilters Free shipping on orders $70+ at DiscountFilters; a fee applies below that · Checked 2026-11-11 · source |
| Also checked 12-pack | $48.95 | DiscountFilters Free shipping on orders $70+ at DiscountFilters; a fee applies below that · Checked 2026-11-11 · source |
Full record with every price, source and date: Holmes HWF100 Filter (Type E) page.
Finding the model number on a Bionaire
Model numbers are on the bottom label, starting with 'BCM' or 'BWF'. Bionaire shares Holmes wick fitments.