When your fireplace isn’t lit, cold air falls and warm air goes up. As a result, a cold draught will enter your home. This can be a problem, but by installing an inflatable chimney balloon you can overcome this. Not only will your room be warmer but you don’t have to pay a lot of money for this.

How Does Chimney Balloon Work?


Chimney balloon is an inflatable device set on your chimney flue and prevents air currents from passing into your home via the chimney. Chimneys, owing to their design, remove the warm air and draw cold air in, and that’s the reason you feel a rush of the air in windows and doors. If you don’t want cold air entering your home you just block the chimney, preventing cold air from coming in and trapping the heat inside at the same.

You just need to insert the balloon in your chimney, inflate it and the device fills the gap so no cold air gets in, but there’s sufficient space for ventilation provided. You can leave this for as long as you want and when you’re done just deflate it and store in a safe place until it’s ready to be used again.

How Many Sizes and Shapes?

A chimney ballon comes in various shapes and sizes so you’re not going to have trouble finding one that fits your chimney. Specific information about the size is available online, and many companies offer custom sizing if you have an irregularly sized chimney.

Figuring out how to measure a chimney isn’t that hard: measure a foot up the chimney flue and from front to back and side to side, with the figures taken inside. To simplify matters use a steel measuring tape or a couple of cardboard set out like wings. Keep in mind you don’t have to get a specific figure as an approximation is all that’s needed. When you have the figure, choose a balloon with the nearest appropriate size or slightly larger.

There are a lot of ways to take the measurement, and if you’re having trouble, it might be easier to do the measurement from the middle to the left and from the center to the right. Combine the two and you’ve got the measurement for your chimney. And if you’re really want to keep things simple, just count the bricks, assuming you’re using regular 9 inch bricks.

What about the Fitting?

Fitting an inflatable balloon is a straightforward process so it should only take a few minutes.

  1. A typical balloon goes 1 or 2 feet over the opening of your fireplace, the depth depending on the size of the balloon and the chimney. The smallest parallel is the most ideal placement provided the handgrip is hidden and the balloon fits right. You’ll know the fitting is right if it doesn’t rub when installed.
  2. The tap should be open so you can blow some air in the balloon, just sufficient for you to put the balloon in the proper position without causing it to scrape. If you’ve got a cast iron fire with an opening for smoke to go through, push the balloon in it before inflating.
  3. When the balloon is in position (the label should be facing towards you), you’re done. Make sure the balloon fits in the flue securely before turning off the tap, and if the air has cooled down you may have to top it up in a couple of hours. Ensure that the balloon is properly positioned when inflating (some of these balloons have a tendency to go over the chimney’s widest point).
  4. Keep going until the balloon has become firm; push the handgrip up, and if it’s springy and hangs with no restraint you’ve done it right. Usually the balloon works fine and without a hitch, but check every 4 months or so just to make certain everything is all right. If winds lead to high chimney suction, use a string to tether the device at the tap.

If you want to remove the balloon, open the tap. Press the handgrip on the chimney’s side through the device so air goes out. Pull out the balloon and store it in a bag or container so you can use it again.

Is There Anything Else I Need to Know?

There are a lot of different balloons for chimneys, but their purpose is the same, and that is to prevent debris, soot, heat loss and draughts and even minimize noise and keep birds from making a mess. While the designs vary, the basic configuration is the same: the balloon or pillow shaped object is inserted in the chimney in the manner described above.

You hold it by the handgrip so your hands don’t get dirty, and as pointed out above you simply inflate it until the balloon grips the walls. A well-designed balloon provides a curve at one of the ends and this usually forms a couple of triangular tunnels, and this provides just the right amount of ventilation so your chimney remains dry without causing drought to come in.

A well-made balloon also keeps rainwater from falling all over your hearth, and if there’s a substantial amount falling down, there’s probably a crack in the chimney fixing, right at the point where it connects on the stack. When you’re shopping for balloon, look for a durable one that is specifically designed to prevent birds from coming in. Another advantage of these balloons is they’re large enough to prevent your pet cat from crawling into the chimney and getting stuck.

If you’re looking for a high quality chimney blocker you may want to check out the SmartBalloon from IQDesign. With this device you’ll be able to minimize the heat lost in your chimney flue. When the SmartBalloon is installed, it acts as a barrier that not only prevents heat loss but also cold draughts. Aside from being affordable, these are also easy to use and it’s built to last.