Storage of padel balls for winter - what a basement, garage and unheated shed do to the pressure

Why padel balls react differently to winter than tennis balls

Padel balls and tennis balls are built on the same basic principle - a rubber core with overpressure, covered with felt. But the padel ball has a lower internal overpressure than the tennis ball. It typically ranges from 10-11 PSI compared to the tennis ball's approximately 14 PSI according to FIP and ITF. The lower baseline pressure makes the padel ball more sensitive to the same percentage pressure drops.

When the pressure drops 1 PSI in a tennis ball, you go from 14 to 13 - about 7 percent. When the pressure drops 1 PSI in a padel ball, you go from 11 to 10 - about 9 percent. The same absolute temperature change hits the padel ball harder on the bounce because it starts closer to the point where the ball begins to feel dead.

Temperature is the primary variable - not humidity

The physics governing the pressure in a padel ball in winter is Gay-Lussac's Law. At constant volume, gas pressure is proportional to absolute temperature. The drop is not dramatic in the short term, but it is constant and cumulative. When you lower the temperature from 20 degrees to freezing, the internal overpressure drops by approximately 7 percent according to physics alone - before diffusion through the rubber even comes into play.

The table below provides estimates built on Gay-Lussac's Law for a padel ball with 10.5 PSI baseline at 20 degrees. The numbers have not been measured in a laboratory with FIP-calibrated equipment, but they indicate the direction physics points.

The numbers above assume that the ball returns to 20 degrees before measurement. If you take the ball directly from a freezing garage and play with it in a heated hall, it will feel significantly flat for the first few minutes while it slowly warms up. This temperature effect will disappear again, but the real problem is that pressure diffuses out of the rubber faster each time the temperature fluctuates.

Humidity affects the felt more than the pressure

The rubber core itself and the overpressure are not significantly affected by moisture. It's the felt that suffers. A padel ball left in a damp basement for five months can absorb enough moisture to make the felt heavy and sticky. This doesn't dramatically change the bounce, but it changes the sound on contact and feels wrong in the hand. Spin is noticeably reduced because the damp felt doesn't grip the strings in the same way.

The combination of coolness and dampness is the worst. Cold takes the pressure. Dampness takes the felt. If you have to choose between two bad rooms, choose the dry one over the warm one. A dry 5-degree cellar is better than a damp 12-degree garage.

The four typical winter storage spaces assessed for padel balls

Here's how the four most common storage locations affect padel balls over an entire winter.

Unused tubes last better than open balls - much better

The most important distinction in winter storage of padel balls is whether the ball is in a sealed pressure tube or in the open air. A new tube is pressurized from the factory, typically to ~11 PSI. The ball inside the tube does not experience the pressure difference between outside and inside - it is in a miniature environment with the same pressure as its own overpressure. This means that diffusion through the rubber is greatly reduced.

An open ball - taken out of the tube after first use - on the other hand, has the ball's overpressure against the atmosphere's normal pressure. This difference slowly pushes air out through the rubber core. This happens all the time, but colder temperatures accelerate it because the rubber's structure changes minimally and becomes slightly more permeable.

Specifically, this means: unused tubes can sit in a cool cellar all winter without noticeable loss. Open balls constantly lose pressure, and an entire winter in an unheated room can cost 10-15 percent of bounce power. That's the difference between a ball that feels good and a ball that feels dead.

We have compiled the general part of the storage discussion in the padel ball storage guide, and the physics behind the pressure drop itself in the article on why balls lose pressure.

Month-by-month winter plan for your padel balls

The simplest plan covers October to April. It suits a typical Danish padel season where many players reduce outdoor or semi-heated play in the coldest months and only play indoors.

What you can do about the pressure drop over winter

The most important single decision is where you store your open balls. If you have space in a heated cupboard and only play once a week, then the answer is simple - put the balls there and you don't need to think further. If, on the other hand, you keep your balls in a garage, an unheated conservatory or a summer house, it's worth considering a pressure container.

A pressure container simulates the environment in which the balls were originally sold. It recreates the overpressure around the ball, greatly slowing down diffusion through the rubber. Our Pressurebox Pro does this automatically - it maintains constant pressure without manual pumping, and gives you fresh balls even after an entire winter in an unheated room. This does not change the fact that the felt can absorb moisture, but it removes the main physical reason why open balls die in winter.

Pressurebox Pro solves the pressure drop. It doesn't solve felt wear or moisture damage to the felt - these are separate problems. Read more about felt and how it wears in the article on padel ball felt quality, and note the difference between new and used balls in the guide on new vs. used padel balls.

In practice: three concrete winter scenarios

Club player, twice a week, heated hall: You use the balls quickly enough that pressure drop doesn't become a real problem. Store your unused tubes anywhere dry. Open balls in a pressure container if you want them to feel consistent from game to game.

Hobby player, once every two weeks, mixing indoor and outdoor: This is where winter hits hardest. If your open balls have 14 days between each session, and they are in an unheated room, you will notice a difference after just two sessions. A pressure container is the simplest solution - or keep open balls in a heated cupboard and use them up before opening the next tube.

We have compiled the comparison between a fresh and a used ball on the difference between new and used padel balls, where the physically noticeable differences are described step by step.