Pool Cover Vents (2026): Air Pillows That Protect Above-Ground Walls
Accessories
Pool cover vents are the inflatable air pillows you center under a solid winter cover so ice expands into the pillow instead of your walls.
Our picks
If you searched pool cover vents hoping for a plastic grille that screws into the cover, pause. Cutting holes in a solid winter sheet is how you invite leaves and rain into the pool. The product that actually protects the walls is an inflatable air pillow centered under the cover.
That pillow is the “vent” in practical deck language. It holds an air pocket so freeze expansion has somewhere to go, and it lifts the middle of the cover so snow and rain shed instead of pooling forever. Pair it with a solid pool winter cover, not a solar blanket and not a mesh lid.
This guide sits in pool accessories next to closing hardware. For weekly debris jobs after open season, the main guide is still the best pool skimmer.
Who needs a pool cover vent
Buy an air pillow if you have:
- An above-ground pool in a freeze climate
- A solid winter cover that rests on the water
- Walls you do not want ice to push outward
Skip it for soft-sided portable pools that do not get a true winter close, and for mesh covers that drain through the fabric. In-ground safety covers use deck pool cover anchors, not a floating pillow.
Size the pillow before you order
Measure the water surface, not the top-rail advertising size. A 4x4 that looked fine in the box can look tiny on a 24-foot round once the cover is on. Large ovals often need one long pillow or two smaller ones tied in a line.
Top pick: Winter Block 4x4
The Winter Block Above Ground Pool Winter Air Pillow, 4' x 4' is the clean default for most round above-ground pools. One square pillow in the center is enough when your pool is not a long oval.
Corner grommets let you rope it so wind and cover drag do not shove it to the wall. Inflate only partway, then seat the pool winter cover over it before you tension the cable. On steel-wall pools, finish the rail with pool cover clips so the skirt cannot balloon.
Best value: Pool Pillows 4x8 2-Pack
Choose the Pool Pillows 4' x 8', 2-Pack when one pillow leaves too much flat cover on a bigger round, or when you want a spare sealed in the shed. Two smaller pillows tied in a line can build a longer ridge without wrestling a 15-foot bladder alone.
Inflate each pillow only partway. Rope both so they stay centered as a pair instead of drifting to opposite walls. On steel-wall pools, finish the rail with pool cover clips after the cover is seated.
Best large oval: 4x15 Winter Pool Air Pillow
The Winter Pool Air Pillow 4x15ft is the long-ridge option. One continuous pillow is easier to keep centered than three small squares that drift apart under a heavy cover.
Plan two people for cover day. A 15-foot pillow is clumsy to float into place alone while the cover waits on the deck. Keep the same 60 to 80 percent fill rule so ice has room to compress the pillow instead of your walls.
How to install without fighting the cover
- Inflate the pillow to about two-thirds full with a household air pump, not a high-pressure compressor.
- Thread rope through every grommet and leave slack so freeze movement does not snap the line.
- Float the pillow to the center and temporarily hold the ropes on opposite uprights.
- Pull the solid winter cover over the pillow so the sheet rests on the water around it.
- Tension the cable or straps, then add rail clips if you run a steel-wall above-ground.
- Set a pool cover pump for the first real rain so standing water does not collapse the dome.
Check the pillow after the first hard freeze. If it drifted, re-center before ice locks the cover in place.
Mistakes that waste a good pillow
- Inflating to drum-tight and hoping ice will somehow compress it
- Skipping the rope so the pillow ends up against one wall
- Using a mesh cover and wondering why the pillow does nothing useful
- Leaving a lake of rainwater on the cover all winter without pumping
- Buying one tiny pillow for a huge oval and calling it done
A pillow is cheap insurance. It is not a substitute for the right cover size, a snug cable, and occasional pumping.
Bottom line
Pool cover vents worth buying are winter air pillows, not HVAC grilles and not cut-in cover hardware. Use the Winter Block 4x4 for a normal round close, the Pool Pillows 2-Pack when you need a second pillow or a spare, and the 4x15 Winter Pool Air Pillow for large ovals. Inflate partway, rope it centered, and keep the solid cover pumped so the air dome can do its job until spring.
Frequently Asked Questions
What are pool cover vents?
In backyard pool talk, pool cover vents usually means the inflatable air pillows you place under a solid winter cover. The pillow creates an air dome so ice expands into the pillow instead of pushing your walls outward.
Are pool cover vents the same as HVAC air vents?
No. You are not buying a wall grille. You want a pool air pillow sized for your above-ground pool and used with a solid pool winter cover.
Do I need pool cover vents with a mesh cover?
Mesh covers drain water through the fabric, so a pillow does less useful work. Solid winter covers are the setup where an air pillow matters most.
How full should I inflate the pillow?
Inflate to about 60 to 80 percent. A rock-hard pillow cannot compress when ice expands, which defeats the point.
How do I keep the pillow centered?
Thread rope through the grommets, place the pillow in the middle, and tie off to uprights or rail caps with a little slack. A pillow that drifts to the wall leaves the center of the cover unsupported.
Can I use a beach ball or exercise ball instead?
Those puncture and go flat. A real winter air pillow uses heavier vinyl and grommets meant for a full season under a cover.
What else do I need to close an above-ground pool?
A correctly sized pool winter cover, pool cover clips on steel-wall rails, and a pool cover pump for standing water on solid sheets.
Do in-ground pools need pool cover vents?
Above-ground walls take the ice load first. In-ground pools usually focus on water tubes, anchors, or a safety pool cover, not a center air pillow.