Choosing between two pleated MERV 8 filters for a furnace or air conditioner comes down to three things: the size of your filter slot, how many replacements you want on hand, and the listed price. Both filters here use electrostatic pleated media and carry a 3-month filter life, so the deciding factors are the dimensions, the pack size, and the upfront price. This kind of decision matters because a filter that doesn't fit your slot is useless even if it has the same MERV rating.
Quick verdict
If you need an 18x18x1 filter, the HDX 18x18x1 3-pack is the straightforward pick. If you need an 18x24x1 filter and prefer more replacements in a single order, the 18x24x1 6-pack makes sense.
| Filter | Listed Price | Pack Count | Size | Frame Material | Filter Life |
|---|---|---|---|---|---|
| HDX 18x18x1 MERV 8 FPR 5 3-Pack | USD 18.95 | 3 | 18x18x1 | Cardboard | 3 Months |
| 18x24x1 MERV 8 HVAC Pleated 6-Pack | USD 36.30 | 6 | 18x24x1 | Paper | 3 Months |
The table shows the main differences: pack count, size, frame material, and listed price. Both filters are rated for a 3-month filter life.
Where each filter wins
- The HDX 18x18x1 3-pack wins on size match for 18x18x1 systems and on the lower listed price between the two.
- The 18x24x1 6-pack wins on size match for 18x24x1 systems and on having six filters in one purchase.
Product notes
HDX 18x18x1 Air Filter MERV 8 Pleated Furnace AC HVAC FPR 5 3-Pack Replacement
This filter is made for furnace, AC, and HVAC systems with an 18x18x1 slot. It combines MERV 8 and FPR 5 ratings, and the pleated electrostatic media captures dust mites, pollen, lint, and pet dander. The cardboard frame and synthetic filter media are typical for a 3-month replacement cycle. The strongest reason to choose it is the size match for 18x18x1 systems, along with a lower listed price than the 6-pack. The limitation is the pack count: with three filters in the package, you will need to reorder sooner than you would with a six-count box if your replacement routine calls for a fresh filter every three months.
18x24x1 Air Filter MERV 8 - HVAC Pleated, Furnace & Air Conditioner 6 Pack
This filter is designed for furnace and air conditioner systems with an 18x24x1 slot. It comes with six filters in one package, so you have more replacements ready before your next change. The pleated electrostatic media is described as dust resistant, and the paper frame matches the 18x24x1 dimensions. The strongest reason to choose it is the six-count supply for an 18x24x1 system, which means fewer reorders. The limitation is that it does not fit an 18x18x1 slot, so you have to confirm the existing filter size before ordering.
Final choice by use case
Measure the slot in your existing system and compare it with the two sizes shown here. For an 18x18x1 system, the HDX 18x18x1 3-pack at USD 18.95 provides three pleated MERV 8 filters that fit that slot. For an 18x24x1 system, the 18x24x1 6-pack at USD 36.30 provides six pleated MERV 8 filters and gives you a larger supply per purchase. The right pick is the one that matches your filter size first; the pack count and listed price then tell you how often you will reorder.
