Top 5 air conditioning myths debunked

Ever wondered exactly how your air conditioner works? Scared it’s spreading germs through the home as one of you is lying sick in bed? Let’s debunk the top 5 most common air conditioning myths we often encounter.

Myth 1: Air conditioners spread germs

One pervasive air conditioner myth is that air conditioners contribute to the spread of germs, including viruses and bacteria, within indoor spaces. 

Modern air conditioning units are often equipped with sophisticated air purification technologies. For instance, systems like Panasonic’s nanoeX technology go beyond simple filtration – they actively neutralise airborne pathogens, enhancing air quality. These advanced features, when coupled with regular maintenance and cleaning, ensure the air circulated by the AC unit contributes to a cleaner and healthier indoor environment.

Myth 2: Air conditioners inject cold air into your home

A common misunderstanding is that air conditioners create cold air and pump it into your home. But this actually isn’t quite right. Air conditioners operate on the principle of ‘heat transfer’. They work by absorbing the warm air inside your home and running it over refrigerant-filled coils to remove heat before recirculating the now-cooled air back into the room.

The outdoor unit, often hot to the touch, is where the absorbed heat is expelled. It’s a continuous cycle of removing warmth, which gives the impression of cold air being generated. However, the reality is that your AC unit is a heat exchanger, not a cold air producer.

So, how does an air conditioner work exactly? 

Step 1: Your indoor unit sucks in warm room air through the grille, pulling it over something called an evaporator coil.

Step 2: This coil is filled with a liquid called refrigerant, which absorbs the heat from the air, leaving it cooler.

Step 3: The cooled air is pushed back into your room, lowering the temperature.

Step 4: As the refrigerant absorbs heat, it turns from a cool liquid into a warm gas, which is pumped outside to the unit in your yard, called the condenser, where a fan blows over the system to remove all the heat.

Step 5: Once the gas has released its heat outside, it turns back into a liquid and goes back inside to collect more heat from your home.

Myth 3: Air conditioners freshen indoor air

It’s a common air conditioner myth that AC units work by pulling fresh air from the outside and bringing it indoors, but this isn’t typically the case, especially in residential settings. As we know from above, air conditioners run through a process of heat exchange. Your air conditioner usually works by recirculating the existing air within your home: taking the indoor air, cooling it down and sending it back into the room. Standard air conditioners don’t exchange indoor air with outdoor air. 

In commercial buildings, regulations often require the air conditioning system to include a portion of outdoor air for better ventilation. This isn’t common in residential air conditioners due to complexity and cost.

Understanding that your air conditioner primarily recirculates indoor emphasizes the importance of room ventilation and the use of exhaust fans or opening windows periodically to introduce fresh air into your home environment.

Myth 4: The bigger the AC, the better its performance

A sizeable air conditioning unit might seem like it would cool your home more effectively, but this is a myth that can lead to less comfort and higher energy bills. So, what happens when an AC unit is too large for the space it’s intended to cool?

Scenario 1: Short cycling

An oversized AC unit cools the room quickly and then shuts off, a phenomenon known as ‘short cycling.’ While it may sound efficient, it’s not, because the unit doesn’t run long enough to dehumidify the air properly, leaving your home cool but clammy.

Scenario 2: Increased humidity

Humidity plays a critical role in how comfortable you feel. If the AC doesn’t run long enough to remove sufficient moisture from the air (because it cools the room too quickly), the result can be a sticky, uncomfortable indoor environment.

Scenario 3: Inefficient energy use

Each time the AC unit starts up, it uses a burst of energy. More frequent cycling means more energy consumed, leading to higher utility bills.

Scenario 4: Wear and tear

The more often the AC unit turns on and off, the more wear and tear it experiences. Over time, this can lead to more frequent repairs and a shorter lifespan for your unit.

Myth 5: Keeping it on saves energy

In the past, this was somewhat true as air conditioners were mostly fixed-speed units—either fully on or off, guzzling significant power with each start. Now, with inverter technology, air conditioners can adjust their output to match the demand, starting up gently and increasing capacity only as needed. This avoids the energy spike associated with powering up, making constant operation less necessary and more of a wasteful habit than a cost-saving strategy.

For the energy-conscious, the smart move is to use programmable thermostats or timers, setting the air conditioner to activate shortly (one hour) before you return home. This way, you’re greeted by a cool environment without having left the system running—and energy-consuming—all day. Those with solar power can enjoy the best of both worlds, running their air conditioners during peak sunlight hours at a moderate temperature to pre-cool the home and then adjusting as the sun sets.