What Is Draft in AC? How To Stop Draft from Window Air Conditioner?

Window air conditioners have been with us for almost a century. They are loved for their durability, efficiency and cost-effectiveness. They’re relatively cheaper than split units and can be used anywhere as long as there’s a sizable window or willingness to insert a hole on the wall.

However, they can be quite a handful when it comes to installation. One of the most common problems homeowners often encounter after window AC installation is draft.

This problem, often attributed to recklessness on the part of the HVAC professional or the type of Window unit you purchase, can affect the performance of your HVAC or heating units and cause them to run tirelessly without much effect in the room, depending on the extent of the draft.

It’s a tricky situation because many times, it may be difficult to tell what the problem is or where the cold blast of air is coming from. This then begs the question; how can you stop the draft from a window air conditioner?

But before we delve into that, we’ll try and explain what draft truly is and reveal some of the causes.

What Is Draft in Air Conditioning System?

Draft can simply be described as cold air finding its way through leaks or openings in your home and replacing warm air that is released through the same opening.

This is caused by temperature and pressure differences between indoor and outdoor air which tend to find a balance by sneaking through pathways of improperly insulated homes.

In air conditioning systems, this may be openings around and between a window unit and the frame or when an AC unit is installed too close to the window.

This situation causes warm air to leave the room faster while cooler outdoor air finds its way into the room. Remember that the AC unit itself can draw cooler outdoor air into the room and release warmer air outdoors.

Furthermore, the vents of the air conditioner are another route for this steady flow of dry, cool air. Drafts can be quite uncomfortable in your room; make you feel cold and can even cause a chill if nothing is done.

Allergies also tend to associate with cold air and if this finds its way into your room, may cause you to fall ill.

What Causes Draft in Air Conditioner?

In plain language, a draft is caused when gaps or spaces in your home provide an escape route for indoor warm air to leave the room, while being replaced by colder outdoor air.

The unwanted cooler incoming outdoor air is what is technically referred to as draft. However, the reason for this air exchange has been technically categorized into two main factors;

Temperature difference

It is normal for warmer surfaces like a rooftop or wall to emit heat. This then creates a normal temperature or pressure differential between indoors and outdoors. But this natural process can be disrupted if there is a poor window installation or the gasket is leaking.

Pressure difference

As your AC functions to cool your home’s indoor temperature, it also emits heat and this causes a significant pressure difference between the indoor and outdoor air. This is why the AC is such an instrumental appliance when we talk about drafting.

These causes can be further broken down into simpler components, and we’ll examine three (3) of them;

1. Wind

Wind is a major factor that causes pressure differences. And as it bellows by a house, it creates suction effects. These air pressure differences affect indoor air which is pulled out through paths that put up the least resistance.

These are gaps in your home, whether through your windows, doors or AC. Once this warm indoor air goes out, cooler outdoor air is pulled in to replace it, which is felt as draft.

2. Stacking effect

This is another scientific reason why drafting occurs. As warm air rises to the top of the house, it causes the atmospheric pressure in that part of the house higher than that of the bottom of the house which socks in cold air from any gaps available.

This is also common in homes that have combustion heaters like fireplaces. The heat rises to the top through the chimney and I automatically replaced at the bottom of the house with pressurized cold air.

3. Extraction fans

These promote ventilation in a room. A ventilation fan used in a kitchen or bathroom is a good example. These fans push fume and steam (along with heat) out of the room while cold air is automatically sucked in to replace it.

Where such ventilation fans do not have a closing mechanism, it continues to allow warmer indoor air out even when not operating.

How To Stop Draft from Window Air Conditioner?

It is best to talk to your HVAC professional and be advised on the best cause of action. However, if you decide to stop draft from the window air conditioner yourself, there are many ways to stop the draft from your window air conditioner, depending on the cause of the problem.

1. Use a pressure regulator

It is best to talk to your HVAC professional about the type to buy. Generally, a pressure regulator will allow you to set your preferred temperature so that it is not affected when you open or close your doors. and avoid problems of temperature fluctuations.

2. Seal window cracks, if any

If you find any cracks on the window where the AC unit has been installed or close to it, you should seal them up to avoid interference and prevent gaps that allow drafting.

3. Use window curtains

Curtains can be put up in front of windows where AC unit is installed. This will serve as a shield against cold air that may want to enter the room and prevent drafting from occurring.

4. Install weather stripping

Weatherstripping is a great way to seal the area around the window frame to prevent outdoor cold air from passing through and entering your home. A good example is the YIJUHOU Seal Foam Tape.

5. Create and install a draft shield

Creating a draft shield is another useful method of preventing draft. Install it just in front of the open window and watch your AC function properly. This will also ensure the operation of your AC unit is not affected by drafts.

6. Try foam sealant tape

Most people create a frame for their window AC unit using wood. At the joint or angle where two pieces of wood meet, there are likely to be cracks and you can seal them using sealant tape. This will make the frame airtight a prevent drafts as well.

7. Add insulation in walls and floors

This is an extra layer of protection that helps to keeps drafts out. Whether it’s traditional insulation materials or heat reflective insulation, you’ll be enhancing your HVAC performance by doing this.

How Do You Prevent Draft in Air Conditioner?

It is often said that the best way to solve a problem is to prevent it. This is also true about drafts, because waiting for it to happen before you act can cause a lot of damage to your health. Simple ways to prevent drafts include;

• Ensure your home is completely and properly insulated and sealed.

• Also ensure you get the right HVAC professional for any AC installation work and ensure the area around the unit is properly sealed using sealants and/or weather stripping.

• Do not install AC too close to windows to prevent pressurised air escaping.

• Weather proof your chimney to prevent drafts.

• Use natural ventilation techniques occasionally by opening doors or windows to prevent a rise in pressure.

Final Words:

For all its benefits and importance, your AC can also cause drafts, or at least if not properly installed. This is why you must be careful who you hire to install your AC units.

Allowing drafts into your home can cause your HVAC system to work more than necessary, causing a rise in energy usage and affecting the lifespan of the unit.

Furthermore, draft can cause you to fall sick if you do not stop it. With this guide, you shouldn’t have much trouble putting things under control.