Why Most Portable Air Conditioners Fall Short and How to Choose the Best One

Are you thinking about buying a portable air conditioner as extreme heatwaves become increasingly frequent? It’s crucial to understand that many portable air conditioners have significant design flaws, and there are no labeling regulations to inform consumers.

When I purchased a portable air conditioner, I was unaware of this issue. The most surprising thing is that there exists a simple solution, and I believe it’s necessary for regulations to change, ensuring that portable air conditioners can’t be sold without it.

First, let’s discuss the misconception, particularly prevalent in the UK, that buying an air conditioner is a mistake. If you don’t require one, that’s perfectly fine. However, many of us live in homes that become excessively hot during heat waves, regardless of our efforts, such as keeping blinds and windows closed. Excessive heat can negatively impact health and even lead to fatalities, as it complicates tasks like studying or working. If it’s acceptable to use energy to heat a home, why is it frowned upon to use energy to maintain a cool environment?

As global temperatures rise, an increasing number of individuals are depending on air conditioners for comfort. It’s vital to minimize energy consumption from these units to reduce carbon dioxide emissions, which contribute to further warming and escalate the demand for cooling solutions.

To comprehend the inherent design flaws, it’s essential to grasp how air conditioners operate. The most efficient systems utilize split configurations. An external unit compresses the refrigerant into liquid form and heats it, which is subsequently cooled by a heat exchanger blowing outside air.

The refrigerant travels through a thin pipe to the indoor unit, where it transforms back into a gas and cools. Indoor air passes through another heat exchanger that cools it by transferring its heat to the refrigerant.

This system allows indoor air to remain inside while extracting heat from it. Split systems typically operate more quietly, with the compressor placed externally. However, these systems are usually costly built-in models, may lack space for outdoor units in upstairs rooms, and few portable split systems are available.

Some portable air conditioners draw outside air into the interior. A wide intake hose pulls in external air while expelling heated air through a separate outlet hose.

These dual-hose air conditioners are less efficient compared to split systems; the exhaust hose can inadvertently transfer heat back into the room. Wrapping this hose in insulation can mitigate some heat transfer. However, similar to split systems, they keep indoor air contained.

In contrast, single-hose portable air conditioners do not utilize intake hoses. Instead, they utilize indoor air to cool the refrigerant, which is then expelled through a single hose, resulting in the continuous influx of hot air from outside.

When a window is open, hot air enters directly. When closed, heat enters through other parts of the house, raising your indoor temperature. Consequently, the air conditioner continuously cools the incoming hot air, leading to higher energy consumption. It’s akin to adding dirt to your laundry detergent.

Additionally, single-hose units become less effective as outdoor temperatures rise, failing to cool spaces as efficiently as dual-hose units providing similar power.

These design flaws remain unaddressed in European labeling. Air conditioner specifications indicate cooling capacity in British thermal units (BTUs), which merely reflects heat transfer capacity, disregarding the continuous influx of hot air necessitating additional heat transfer.

The same applies to the Seasonal Energy Efficiency Ratio (SEER). These figures often compare units without accounting for the unique efficiency shortfalls of single-hose models, which are generally easier to install.

“Consumers struggle with two ducts and may lack the space for proper venting,” explains Chris Michael from Meaco. Thus, it’s not surprising that homeowners gravitate towards single-hose units, which are more accessible than dual-hose alternatives in the UK.

Conversely, the US has improved labeling standards. Two measures now account for the hot air entering the room and the heat expelled via the exhaust hose. The Seasonally Adjusted Cooling Capacity (SACC), often declines by over a third compared to unadjusted capacity figures.

Moreover, the overall energy efficiency ratio (CEER) provides additional insights into the efficiency of dual-hose air conditioners.

Nonetheless, these metrics still do not fully inform buyers. Both SACC and CEER measure efficiency under specific conditions, often assuming an outdoor temperature of 28°C (82.4°F) for most operation time, escalating to 35°C (95°F) for brief intervals. This is misleading, as cooling demand spikes at 40°C (104°F).

Interestingly, many single-hose air conditioners are essentially dual-hose systems with a single hose. Adding an additional hose and attachment resolves this defect. At least one manufacturer, GE, offers conversion kits for certain single-hose models, boasting increased cooling capacities. Their advertising claims this could triple cooling efficiency.

Numerous individuals have undertaken DIY conversions—from simple tape and cardboard solutions to 3D printed components. Feedback indicates it’s a game-changer; I experienced this firsthand during the UK’s May heatwave, concluding it significantly enhanced my comfort.

Therefore, in my opinion, the labeling of portable air conditioners in the UK and EU must evolve to accurately represent their performance during peak heatwave conditions. It’s both strange and misleading for a single-hose air conditioner to receive an “A” rating for efficiency.

Ideally, the sale of single-hose models should be prohibited entirely. Portable air conditioners should only be sold as dual-hose units, with the option for single-hose operation when dual-hose setups are impractical. In essence, single-hose air conditioners should not be sold without an accompanying conversion kit. Michael from Meaco indicates they are contemplating introducing such a model by 2027.

I attempted to ascertain who regulates portable air conditioners in the UK, but received no information. The Department of Energy Security and the Department of Net Zero did not respond to inquiries, nor did the Energy Saving Trust. However, I hope someone in a position of influence reads this. Achieving climate victory through improved air conditioning standards is possible.