--- product_id: 312123344 title: "AC Infinity Inline Filter Box 4\" with High Efficacy Filter, Whole House HVAC Filtration Kit, Fits 4-Inch Inline Duct Fans for Fresh Air Intake and Ventilation" brand: "ac infinity" price: "β‚±33884" currency: PHP in_stock: true reviews_count: 13 category: "Ac Infinity" url: https://www.desertcart.ph/products/312123344-ac-infinity-inline-filter-box-4-with-high-efficacy-filter store_origin: PH region: Philippines --- # MERV 13 high efficacy filter traps fine particles 400 CFM max airflow for powerful ventilation 1mm thick cold-rolled steel for durability AC Infinity Inline Filter Box 4" with High Efficacy Filter, Whole House HVAC Filtration Kit, Fits 4-Inch Inline Duct Fans for Fresh Air Intake and Ventilation **Brand:** ac infinity **Price:** β‚±33884 **Availability:** βœ… In Stock ## Summary > 🌿 Elevate your air game β€” because fresh air is the new luxury. ## Quick Answers - **What is this?** AC Infinity Inline Filter Box 4" with High Efficacy Filter, Whole House HVAC Filtration Kit, Fits 4-Inch Inline Duct Fans for Fresh Air Intake and Ventilation by ac infinity - **How much does it cost?** β‚±33884 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.ph](https://www.desertcart.ph/products/312123344-ac-infinity-inline-filter-box-4-with-high-efficacy-filter) ## Best For - ac infinity enthusiasts ## Why This Product - Trusted ac infinity brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - β€’ **Seamless Integration:** Fits perfectly with 4-inch inline duct fans like CLOUDLINE S4 & T4 for optimized fresh air intake. - β€’ **Effortless Maintenance:** Slide lock door with neoprene seal offers quick, dust-free filter changes without hassle. - β€’ **Breathe Cleaner, Live Better:** Includes a MERV 13 filter that captures dust, lint, odors, and PM 2.5 particles for healthier indoor air quality. - β€’ **Powerful Airflow, Zero Compromise:** Supports up to 400 CFM airflow, balancing high performance with quiet operation. - β€’ **Built to Last, Engineered to Perform:** Heavy-gauge alloy steel construction ensures weatherproof durability and long-term reliability. ## Overview The AC Infinity Inline Filter Box 4" is a robust HVAC filtration solution designed for 4-inch inline duct fans. Crafted from 1mm thick cold-rolled alloy steel with aluminum flanges, it withstands extreme conditions while delivering up to 400 CFM airflow. Equipped with a MERV 13 high efficacy filter, it effectively traps dust, dirt, lint, odors, and fine particles like PM 2.5, ensuring cleaner, healthier indoor air. Its slide lock door and neoprene seal enable easy, dust-free filter maintenance, making it an ideal upgrade for whole-house ventilation systems. ## Description Product description Product Description A whole-house air filtration system designed for use with inline duct fans such as the CLOUDLINE Series, to circulate fresh air by blocking particles like dust and dirt from entering your home in intake applications. Each air filter box is built using 1mm thick cold-rolled steel and finished with matte black powder coating. This outer body build comes together with aluminum duct flanges to create a sturdy build capable of withstanding inclement weather. Its low-maintenance design features a hinge-sealed door equipped with a slide lock that provides easy access to the inner chamber. The door is lined with a soft neoprene layer that keeps the filter in place and dust from seeping inside. Applications Each air filter box accepts standard MERV filter replacements that slide into the inner chamber’s filter slot. Comes included with a high-efficacy pleated air filter, capable of trapping 0.3-1.0 micron-sized particles such as Dust Dirt Lint Odor The duct flanges fit with matching-sized inline fans and enable a streamlined installation to create high-efficiency filtration in HVAC and grow applications. Attaching the air filter box to the starting end of your ductwork will dramatically reduce suspending particles in the air inside your home. Use with a high static pressure fan like the CLOUDLINE Series of duct fans is highly recommended to ensure maximum filtration. HVAC Filter Box Intake air filtration system designed to circulate fresh air and block particles from entering indoor settings. Home Inline Air Filtration When used with a high static pressure duct fan, filter boxes can not only purify the air with maximum efficiency but also provide light cooling to improve comfort. Place this filter box at the beginning of your ductwork to keep dust, dirt, lint, and odors out, reducing suspending particles inside your home. Sturdy and Weather-Resistant Made of 1mm thick cold-rolled steel and aluminum duct flanges with a matte black powder coating finish encasing the interior filter, held in place by neoprene padding. Easy Access Design Slide lock hatch system provides quick access to the inner chamber's filter slot for direct and speedy replacement, accepting standard-sized MERV filters. High Efficacy Protection Review: Great box, worth the money! - Great filter box. Built with good materials. Hinges are smooth and the latch is solid and looks and works great. I used this for my fresh air intake with a motorized damper for my A/C system. The inlet and outlet flanges were true to size and the door sealed very well with no leakage. It was easy to install and remove the included filter. This is heavy gauge metal and makes the box have some weight to it, so be prepared to have a way to mount or hang it. It's easy to tell this is a good product. The shipping box and packing were really nice....I hated to throw it away. You get quality with this box, it's worth the money, which is hard to find these days. Review: Filter box review - The filter box was delivered as scheduled and very well packaged. Product is well designed, fabricated and finished. There are "no" sharp edges from manufacturing. Keep in mind there are no provisions or suggestions for hanging or mounting. Drilling four holes for mounting potentially voids any warranty. I used #10 lag screws supplemented with 1.5" fender washers. ## Features - A duct filter box designed for use with inline fans to circulate fresh air and block dust and odors. - Built with 1mm thick cold-rolled steel and aluminum duct flanges, able to withstand extreme weather. - Slide lock door gives easy access to inner chamber while soft neoprene layer creates dust-free seal. - Includes a standard high efficacy filter that traps particles like dust, dirt, lint, and odor. - 23.46 x 8.42 x 11.73” | Fits 4” Inline Fans | 400 CFM Maximum | Accepts 12 x 20 x 1” Filters ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B0921N33Y7 | | Best Sellers Rank | #60,579 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #392 in Furnace Filters | | Brand | AC Infinity | | Brand Name | AC Infinity | | Compatible Devices | CLOUDLINE S4, CLOUDLINE T4 | | Customer Reviews | 4.6 out of 5 stars 326 Reviews | | Item Dimensions L x W x Thickness | 23.46"L x 8.42"W x 11.73"Th | | Item Weight | 6.42 Kilograms | | MERV Rating | 13 | | Manufacturer | AC Infinity | | Manufacturer Part Number | AC-AFB | | Material | Alloy Steel | | Material Type | Alloy Steel | | Model Number | AC-AFB4 | | Number of Items | 1 | | Product Dimensions | 23.46"L x 8.42"W x 11.73"Th | | Product Grade | new | | UPC | 819137021693 | | Unit Count | 1 Count | ## Product Details - **Brand:** AC Infinity - **Compatible Devices:** CLOUDLINE S4, CLOUDLINE T4 - **Item Weight:** 6.42 Kilograms - **MERV Rating:** 13 - **Manufacturer:** AC Infinity - **Material:** Alloy Steel - **Number of Items:** 1 - **Product Dimensions:** 23.46"L x 8.42"W x 11.73"Th - **Product Grade:** new - **UPC:** 819137021693 ## Images ![AC Infinity Inline Filter Box 4" with High Efficacy Filter, Whole House HVAC Filtration Kit, Fits 4-Inch Inline Duct Fans for Fresh Air Intake and Ventilation - Image 1](https://m.media-amazon.com/images/I/41EWnjz-1aS.jpg) ![AC Infinity Inline Filter Box 4" with High Efficacy Filter, Whole House HVAC Filtration Kit, Fits 4-Inch Inline Duct Fans for Fresh Air Intake and Ventilation - Image 2](https://m.media-amazon.com/images/I/51keHQnx4lL.jpg) ![AC Infinity Inline Filter Box 4" with High Efficacy Filter, Whole House HVAC Filtration Kit, Fits 4-Inch Inline Duct Fans for Fresh Air Intake and Ventilation - Image 3](https://m.media-amazon.com/images/I/51NyArbfr0S.jpg) ![AC Infinity Inline Filter Box 4" with High Efficacy Filter, Whole House HVAC Filtration Kit, Fits 4-Inch Inline Duct Fans for Fresh Air Intake and Ventilation - Image 4](https://m.media-amazon.com/images/I/61yP1T29OcL.jpg) ![AC Infinity Inline Filter Box 4" with High Efficacy Filter, Whole House HVAC Filtration Kit, Fits 4-Inch Inline Duct Fans for Fresh Air Intake and Ventilation - Image 5](https://m.media-amazon.com/images/I/61ubRjGZ8mL.jpg) ## Available Options This product comes in different **Size** options. ## Questions & Answers **Q: what filter fits perfect in the 4" filter box?** A: the 4" and 6" filters take 12x20x1" filters; the 8 and 10" box's take 14x20x1" filters **Q: What filter replacement is suggested for the 6" filter box? standard 20x12x1 does not fit.** A: Different brands of filters have different "actual" sizes. Look up the true size of the filter you are using, then check actual filter sizes for different brands that are smaller. **Q: Do the filters trap smoke from pipes or pollen and mildew?** A: No, you need a carbon filter for smoke **Q: Can I use a MERV 17 or HEPA filter instead of a MEV13 filter for additional filtration if they will even fit?** A: I use the HDX FPR 12 Ultimate Allergen with odor reduction. This filter is a higher end filter. ## Customer Reviews ### ⭐⭐⭐⭐⭐ Great box, worth the money! *by T***D on October 8, 2025* Great filter box. Built with good materials. Hinges are smooth and the latch is solid and looks and works great. I used this for my fresh air intake with a motorized damper for my A/C system. The inlet and outlet flanges were true to size and the door sealed very well with no leakage. It was easy to install and remove the included filter. This is heavy gauge metal and makes the box have some weight to it, so be prepared to have a way to mount or hang it. It's easy to tell this is a good product. The shipping box and packing were really nice....I hated to throw it away. You get quality with this box, it's worth the money, which is hard to find these days. ### ⭐⭐⭐⭐⭐ Filter box review *by R***H on April 18, 2026* The filter box was delivered as scheduled and very well packaged. Product is well designed, fabricated and finished. There are "no" sharp edges from manufacturing. Keep in mind there are no provisions or suggestions for hanging or mounting. Drilling four holes for mounting potentially voids any warranty. I used #10 lag screws supplemented with 1.5" fender washers. ### ⭐⭐⭐⭐⭐ Great Fresh Air System - Filter Out Wildfire Smoke *by M***S on December 3, 2023* I live in an area plagued by wildfire smoke and every year gets worse. I live in a Valley so temperature inversions are common and many of my neighbors have wood buring stove and some even illegally burn thei household garbage. I have indoor air cleaners which keep my indoor air quality index (AQI) very low, 1 to 4. However, Carbon Dioxide (CO2) levels get very high, especially in the bedroom when it can reach as high a 1400 ppm in the morning. Anything above 1000 ppm can cause headaches, fatigue, and other health issues. I assembled the system pictured it consists of the following: * AC Infinity Inline Filter Box fitted with Filterbuy 12x20x1 MERV 13 rated filters * AC Infinity Cloudline Pro S4 Inline Duct Fan * AC Infinity Flexible 4-inch Aluminum 4 layer HD Flex Hose (25') * Broan-NuTine 465B 4" to 5" Duct Adaptor * Gulrear Portable AC Window Vent Kit 5" I assembled these components and it allows me to draw in air from the outside, filter it, and disperse into the room. The 25' hose allowed me to place the outlet just below the top of the ceiling where monitoring have indicated is the best location. I use the IQ Air Airvisual Pro N1 indoor air quality monitor in the bedroom to track the AQI Index and most importantly for this purpose, the CO2 level. Prior to installing this system my highest reading in the morning averaged 950 ppm. Now I average 650 ppm. My 24 hour/day monthly average went from 735 ppm to 588 ppm. I am very pleased with the performance of the system and achieved my goal of reducing CO2 levels when I am unable to open the windows due to unhealty outdoor air quality. The AC Infinity products are of excellent quality and the inline Duct Fan is very quiet. I leave set at the 5 (out of 10) power level and it is very quiet. The combination of my air cleaner and the AC Infinity fan makes a great white noise level for restful sleep. In the pictures you will see how I have hidden some of the components under a chair. You can also see the hose outlet hidden behind the flower vase on top of the armoire. Update: Condensation inside the filter box was a concern, but with outside temps since installing in mid-October ranging from 65Β° to 22Β° F we have had zero moisture build up inside the filter box. Dry as a bone. ## Frequently Bought Together - AC Infinity Inline Filter Box 4" with High Efficacy Filter, Whole House HVAC Filtration Kit, Fits 4-Inch Inline Duct Fans for Fresh Air Intake and Ventilation - AC Infinity CLOUDLINE PRO S4, Quiet 4” Inline Duct Fan with Speed Controller – EC Motor Ventilation Exhaust Fan for Heating Cooling Booster, Grow Tents, Hydroponics - AC Infinity Flexible 4-Inch Aluminum Ducting, Heavy-Duty Four-Layer Protection, 8-Feet Long for Heating Cooling Ventilation and Exhaust --- ## Why Shop on Desertcart? - πŸ›’ **Trusted by 1.3+ Million Shoppers** β€” Serving international shoppers since 2016 - 🌍 **Shop Globally** β€” Access 737+ million products across 21 categories - πŸ’° **No Hidden Fees** β€” All customs, duties, and taxes included in the price - πŸ”„ **15-Day Free Returns** β€” Hassle-free returns (30 days for PRO members) - πŸ”’ **Secure Payments** β€” Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** β€” Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.ph/products/312123344-ac-infinity-inline-filter-box-4-with-high-efficacy-filter](https://www.desertcart.ph/products/312123344-ac-infinity-inline-filter-box-4-with-high-efficacy-filter) --- *Product available on Desertcart Philippines* *Store origin: PH* *Last updated: 2026-05-29*