---
product_id: 312123344
title: "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: "€ 434.01"
currency: EUR
in_stock: true
reviews_count: 10
category: "Ac Infinity"
url: https://www.desertcart.fr/products/312123344-inline-filter-box-4-with-high-efficacy-filter-whole-house
store_origin: FR
region: France
---

# MERV 13 high efficacy filter traps fine particles 400 CFM max airflow for powerful ventilation 1mm thick cold-rolled steel for durability 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:** € 434.01
**Availability:** ✅ In Stock

## Summary

> 🌿 Elevate your air game — because fresh air is the new luxury.

## Quick Answers

- **What is this?** 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?** € 434.01 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.fr](https://www.desertcart.fr/products/312123344-inline-filter-box-4-with-high-efficacy-filter-whole-house)

## 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

- • **Seamless Integration:** Fits perfectly with 4-inch inline duct fans like CLOUDLINE S4 & T4 for optimized fresh air intake.
- • **Effortless Maintenance:** Slide lock door with neoprene seal offers quick, dust-free filter changes without hassle.
- • **Breathe Cleaner, Live Better:** Includes a MERV 13 filter that captures dust, lint, odors, and PM 2.5 particles for healthier indoor air quality.
- • **Powerful Airflow, Zero Compromise:** Supports up to 400 CFM airflow, balancing high performance with quiet operation.
- • **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

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 - desertcart.com

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 | #44,986 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #292 in Furnace Filters |
| Brand Name | AC Infinity |
| Compatible Devices | CLOUDLINE S4, CLOUDLINE T4 |
| Customer Reviews | 4.6 4.6 out of 5 stars (324) |
| 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 Type | Alloy Steel |
| Model Number | AC-AFB4 |
| Number of Items | 1 |
| 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

![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)

## 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 65° to 22° 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

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*Product available on Desertcart France*
*Store origin: FR*
*Last updated: 2026-04-27*