Outdoor and indoor AC covers help block drafts, reduce heating costs, and keep units free from dust, leaves, and moisture during winter. This guide highlights five top options suited for different setups—outdoor units for long-term weather exposure, indoor window units for inside blocking, and versatile designs for brackets or inner installations. Best for homeowners seeking energy savings, protection from winter elements, and easy installation.
| Product | Best For | Key Benefit |
|---|---|---|
| TOHONFOO Window Air Conditioner Covers for Outside (21″W x 15″H x 16″D) | Outdoor units with brackets | Three-layer insulation blocks drafts |
| BEWAVE Indoor Air Conditioner Cover (25″x17″x3.5″) | Indoor window units | Energy savings and dust protection |
| TOHONFOO Window Air Conditioner Covers for Outside (24″W x 15.6″H x 20″D) | Mid-size outdoor units | Three-layer insulation and bracket-friendly |
| HOXHA Indoor Air Conditioner Cover for Window Units | Indoor window units | Double insulation and easy drawstring fit |
| THERMWELL AC2H Window Cover (18x27x16″), Frost King | Medium outdoor/window units | Durable polyethylene protection |
TOHONFOO Outdoor Window AC Cover 21″W x 15″H x 16″D
Best for compact outdoor units with support brackets. This cover features a three-layer insulation system: 600D waterproof windproof fabric, 2mm pearl cotton, and insulated aluminum foil. The inner dimensions are 21″W x 16″D x 15″H, designed for units up to 20.5″W x 15.5″D x 14.5″H. The bottom-cut design accommodates brackets underneath. Caution: measure your unit precisely to ensure a proper fit.
BEWAVE Indoor Window AC Cover With Drawstring
Best for interior use on window AC units in temperate climates. It provides energy-saving benefits by blocking cold air from entering the room and preventing warm air leaks. Constructed from 210D polyester and cotton, the cover resists dust while staying machine washable and reusable. It’s easy to install with a drawstring system on one side. Limitation: intended for indoor use and may not seal completely against heavy winter drafts in extremely cold climates.
TOHONFOO Outdoor Cover, 24″W x 20″D x 15.6″H
Best for medium outdoor units with brackets underneath. It uses the same three-layer insulation system as the smaller model, designed to fit units up to 23.5″W x 19.5″D x 15″H. Bottom-cut sections simplify bracket adaptation. Caution: check inner dimensions carefully to match the actual outer dimensions of your AC unit before purchase.
HOXHA Indoor Window AC Cover with Double Insulation
Best for indoor protection of window units to reduce cold drafts and dust ingress. Double-layer insulation minimizes heat loss and reduces heating costs in winter. Easy to install with adjustable drawstrings on both sides. A limitation: primarily suited for inside use; it may not seal as tightly as outdoor covers in severe winter conditions.
THERMWELL AC2H Window Cover
Best for medium outdoor/window units that need simple protection from water and dust. Made of durable polyethylene, it blocks out water, ice, dust, and leaves. The design is straightforward and may be best for units requiring quick, no-fuss coverage. Limitation: single-layer external protection may be less effective against heavy wind-driven rain compared with multi-layer designs.
Buying Guide: Key Factors To Consider
- Unit location: Outdoor covers endure wind, snow, and moisture; indoor covers guard against indoor drafts and dust.
- Size compatibility: Always measure outer dimensions of your AC unit and compare to the cover’s inner dimensions and recommended fit.
- Insulation level: Three-layer insulation blocks drafts effectively; single-layer options may be cheaper but less protective.
- Bracket compatibility: Some covers have bottom-cut designs to accommodate support brackets under outdoor units.
- Material durability: Look for water-resistant fabrics, UV resistance, and easy maintenance (washable or wipe-clean).
- Installation: Drawstrings, adjustable hems, and tool-free setups save time and reduce installation errors.
- Ventilation: Ensure the cover allows moisture to escape to avoid mold buildup inside the unit.
Frequently Asked Questions
- What is the main difference between outdoor and indoor AC covers? Outdoor covers protect from weather elements and drafts for external units; indoor covers focus on dust, wind, and cold air infiltration into indoor window units.
- How do I know which size to buy? Measure the outer dimensions of your AC unit and choose a cover with inner dimensions that exceed those measurements by a small margin for a comfortable fit.
- Are double insulation covers worth it for winter? Yes, they offer extra protection against cold drafts and can improve overall energy efficiency in heated spaces.
- Can indoor covers be machine washed? Many are machine washable; check the care instructions provided by the manufacturer.
- Do covers affect unit performance when the AC is in use? Covers are intended for off-season storage; avoid using a cover while the unit is operating.
