Air conditioners may disturb sleep

A study reveals that when airflow from an air-conditioner is directed at a human body at an insensible velocity, it may increase heart rate and affect sleeping positions.

The results, published in the journal of Energy and Buildings, indicated that the participants had significantly greater body movements, an increased heart rate and a higher frequency of waking in the room where the AC had a mean velocity of 0.14 m/s.

This meant that the cold airflow may have a greater impact on the overall sleep of the participants with lower physical strength or a greater sensitivity to cold.

According to researchers of Toyohashi University of Technology in Japan, airflow from an AC stimulates the human body while sleeping and impacts on sleep conditions even if the mean airflow velocity is lower than an insensible level.

The study suggests that some AC settings may have an unintentional negative impact on sleep quality despite the comfort the person feels.

The research team, led by professor Kazuyo Tsuzuki, had the subjects sleep in two bedrooms using ACs set at different airflow velocities.

The participants felt cooler with the higher airflow velocity during wakefulness and sleep.

However, no significant difference was observed in the feeling of comfort, length of sleep depth, skin temperature, rectal temperature or sense of warmth or coolness in each subject before sleeping.

The result is useful clue as to how to configure the airflow velocity of an AC to create a comfortable sleeping environment.

Configuring the airflow velocity of the air-conditioner to a comfortable sleeping environment may help in quality of sleep!