How to make portable air conditioner window seals look more attractive — 4 easy ways to make them look better from both inside and out

If you've managed to get your hands on a portable air conditioner this summer, you'll know that, in order for it to work most effectively, you'll need to install a window kit.

After all you need to vent a portable air conditioner outside so that it can expel hot air, and the seal works to keep this hot air out, which means your appliance can work in the most energy efficient way possible. But let's be honest, these window kits don't always look the best.

So how can you make them look more attractive? I asked the experts for their best tips.

1. Make sure you use the correct seal for your window type

First up, it's important to use the right seal for your window type. Many portable air conditioners come with two types of seal: one that is a rigid and slides to fit gaps in sliding windows, and another universal kit that includes a fabric seal, with a zip through the middle and a roll of hook and loop tape to help attach it to the window frame.

The rigid vent is arguably the better looking out of the pair, but is only suitable for sash windows where you can easily eliminate any gaps that could let hot air back in the room.

I've seen people on social media using these rigid vents vertically in a casement window (and that may be an option if you rent and can't apply the hook and loop tape to the window frame for a fabric seal), but this won't create the most effective seal.

2. Take your time applying the window seal

If a fabric seal is the most suitable for your window type, then taking the time to apply it carefully will help keep it looking neat.

'Most of the complaints about fabric seals looking messy come from loose fitting, excess material hanging down or gaps around the edges, so take time to measure the window properly, pull the fabric seal tight before attaching it and make sure the zip opening around the hose is snug,' says Rhys Powell, Director of Operations at WarmZilla. 'A well-fitted seal looks much more intentional and also works better because it stops warm air leaking back into the room.'

Over the summer, when my window seal isn't in use, I leave it attached to the window but fold it on on itself so that it's not visible from outside. Then once the summer is over, I remove the seal and fold it away for next year. I leave the hook and loop tape in place as it matches the colour of the window frame so is barely visible.

3. Try a DIY alternative

If you love a bit of DIY, then you could always make your own fabric seal, using material that better suits your home and tastes. But remember your choice of fabric will impact the effectiveness of keeping the heat out when the window is open and the appliance is in use. Fabric seals included with most portable air conditioners tend to be made from a tightly woven polyester that has been coated to weatherproof it.

But fabric isn't your only option.

'A made-to-measure clear acrylic panel is a much neater alternative because it creates a clean, almost glass-like finish rather than covering the window with fabric,' explains James Bryant, Founder of Cut My, that offers cut-to-size acrylic air conditioner window seals, with an opening sized specifically for the exhaust hose.

'Acrylic or polycarbonate can be effective for a DIY seal, but accurate measuring is essential,' he says. 'A badly fitting panel can leave gaps, put pressure on the window frame or become unstable.'

It's also important that any DIY option like this is still fitted properly and safely. 'People should avoid permanently altering rented windows and make sure the panel does not interfere with hinges, locks or safety restrictors,' adds James. 'The hose should follow the air-conditioning manufacturer’s guidance, remain unobstructed and be kept as short and straight as reasonably possible. Never use ordinary glass or brittle offcuts, as these are harder to cut safely and may break.'

While social media might provide inspiration for other DIY seals, it's important you focus on effectiveness as a priority, as Rhys explains: 'A homemade seal needs to create a proper barrier around the exhaust hose without putting strain on the window or creating gaps where hot air can escape. What you're seeing on Instagram might look good in photos but fail in practice because it has small openings that allow warm air back into the room. If you're making your own solution, prioritise a tight seal and safe installation over appearance. A portable air conditioner will only perform properly if the hot air it removes is directed fully outside.'

4. Vent through a wall

Another option is to avoid venting your portable air conditioner out of a window and vent it through the wall instead. I recently reviewed the Dreo portable air conditioner which came with a wall vent included. This is a permanent option, so likely won't be suitable for those who rent, but it will feel a lot more discreet that a window seal.

Unless you are competent with DIY like this, it's a job left for a professional, as it's vital it's done correctly so that it's effective.