Sleep Quality Improves With Better Ventilation
Results from a four-week study published in Science of The Total Environment found that people experience better sleep quality when they have increased bedroom ventilation.
"Sleep is crucial for our health, well-being, and productivity," said lead author Xiaojun Fan. "The bedroom is where we sleep and spend approximately one-third of our lifetime."
To investigate the connection between sleep quality and bedroom ventilation, the researchers conducted an in-depth study using 35 participants. The participants were carefully selected.
The study was conducted in Belgium. All participants had bedrooms with centralized ventilation systems that could be changed without the participants' knowledge.
The experiment lasted four weeks. During this time, the researchers monitored various factors, including carbon dioxide concentration, relative humidity, and the temperature of the rooms.
Ventilation rates had a significant impact on carbon dioxide concentrations. As expected, the levels were higher when ventilation was low. This is because airflow was being restricted.
Relative humidity also changed with the various ventilation rates. However, these differences were only slight and remained within optimum levels.
When ventilation settings were changed from low to moderate, researchers found that participants had fewer night wakes. They also had more deep sleep. Lead author Fan recommends that people sleep with an open window as an effective step to improve sleep quality.
//New words//
Monitor: To watch and check a situation carefully for a period of time to discover something about it
Ex) The CIA was monitoring his phone calls.
Concentration: The exact amount of one particular substance that is found in another substance
Ex) High concentrations of toxic elements were found in the polluted areas.
Restrict: To limit the movements or actions of someone, or to limit something and reduce its size or prevent it from increasing
Ex) Having small children really restricts your social life.
Optimum: Being the best or most likely to bring success or advantage
Ex) For optimum flavour, prepare just before serving.
Moderate: Being within a middle range in size, amount, or degree; neither great nor little
Ex) The rent has increased over the years but in moderate amounts.
//Questions//
1. What did all of the participants have?
Answer: All of the participants had bedrooms with centralized ventilation systems that could be changed without their knowledge.
Reason: (4th Paragraph) The study was conducted in Belgium. All participants had bedrooms with centralized ventilation systems that could be changed without the participants' knowledge.
2. Why were carbon dioxide levels higher when the ventilation was low?
Answer: Carbon dioxide levels were higher when the ventilation was low because airflow was being restricted.
Reason: (6th Paragraph) As expected, the levels were higher when ventilation was low. This is because airflow was being restricted.
3. What does Fan recommend?
Answer: Fan recommends that people sleep with an open window as an effective step to improve sleep quality.
Reason: (8th Paragraph) Lead author Fan recommends that people sleep with an open window as an effective step to improve sleep quality.
//Discussions//
Q1. Do you tend to sleep through the night without waking up? Please discuss.
->
No, I sometimes wake up once during the night.
It could be 2 o'clock after midnight or 5 a.m.
However, sometimes I can sleep all night without waking up.
Then I feel so good when I wake up in the morning.
To achieve this, it seems necessary to exercise well during the day, eat well, and take a bath for 2 to 3 hours before going to bed.
Q2. Would you rather sleep in a warm room or a cold room? Please explain.
->
When I go to sleep for the first time, I want to sleep in a room that is a little cold.
After that, I want to sleep in a reasonably warm room.
Because I can't sleep well if the room is hot when I sleep.
If you warm up your body before going to bed and cool down a little when you go to sleep, it will cool down a little, making it easier to sleep.
However, if you stay in a cold room, you will wake up mid-day due to the cold.
So after I go to bed, I want to sleep in a reasonably warm room.
Q3. Do you find falling asleep in an unfamiliar place complicated? Why or why not?
->
Yes, it won't be easy.
This is because you can sleep in a familiar place with peace of mind, but if you are in an unfamiliar place, many things are different, and you cannot rest comfortably.
However, even if you travel and stay in a hotel, your body will be exhausted, so sleeping won't be too difficult.
Q4. Would you be happy sleeping in a room with an open window? Please share your thoughts.
->
No, I don't think so.
Because the temperature outside is usually not pleasant.
In the summer, you need an air conditioner; in winter, you need a heater.
Of course, if the temperature outside is not too cold or hot, it may be okay to open the windows.
It is also necessary to have a quiet, safe environment outside with a nice breeze coming in.
In other words, if you can sleep in a room with an open window, you are close to heaven.
Q5. Do you like to get eight hours of sleep per night? Please explain.
->
No, because I feel good after seven and a half hours of sleep.
If I could wake up without an alarm clock, I would be able to wake up in the morning feeling great.
If possible, I would like to wake up without an alarm clock, not only on weekends but also on weekdays.
Q6
Would you like to take part in a sleep study? Why or why not?
->
No, I don't want to participate.
I don't want anyone to watch me while I'm sleeping.
However, if any good research and information is helpful to us, we would always like to know.
Sleep Quality Improves With Better Ventilation
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Using Indoor Air Quality Tactics To Sleep Better At Night, Perform Well The Next Day
1)
A busy mind may not be the only thing to blame if falling asleep and staying asleep is a nightly struggle. The temperature and pollutants in the air, as determined by a bedroom's heating, cooling and ventilation, could be the culprits.
People tend to fall asleep faster in bedrooms with comfortable temperatures and good air quality. These conditions also improve sleep quality, according to Pawel Wargocki, Ph.D., associate member of ASHRAE.
2)
The bedroom temperature should be set to a comfortable level before bed for a good night's sleep. Published research shows that the temperature is usually lower at bedtime than in the morning. Raising the bedroom temperature slightly during the night helps make the bedroom more comfortable the following day, says Wargocki, an associate professor at the Technical University of Denmark.
3)
"If you want to fall asleep quickly, you should avoid overheating," he said. "If you wake up in a very stuffy environment, it's unpleasant."
He said that people also tend to sleep better and feel better the next day when they sleep in a well-ventilated environment.
When a bedroom's window and door are closed for privacy and energy conservation, the room's ventilation rate is "so low that carbon dioxide (CO2), an indicator of poor indoor air quality (IAQ), routinely exceeds 2,500 to 3,000 ppm, which is three times the recommended level," according to published measurements.
4)
EFFECT OF INDOOR ENVIRONMENT ON SLEEP
Wargocki and his colleagues at the Technical University of Denmark studied the ventilation rate in a bedroom to see how it affected the sleep and performance of a group of students the next day. The research showed that sleep quality and performance the next day could be improved by increasing the supply of clean outdoor air in bedrooms.
5)
"We know from other research that sleep quality generally affects performance the next day," Wargocki said.
He presented the study during a seminar sponsored by TC 2.1, Physiology and Human Environment, and ASHRAE Standing Standard Project Committee 55, Thermal Environmental Conditions for Human Occupancy, at the 2016 ASHRAE Annual Conference in St Louis.
6)
Wargocki said only a handful of groups are researching indoor environmental conditions and ventilation in bedrooms, and the research is rarely conducted in the subject's bedroom.
There are many reasons for the lack of research in this complex area, including factors that affect sleep quality, such as type of bedding, sleepwear, external noise disturbance and outdoor climate, Wargocki said. Other reasons include people not allowing access to the most private part of their homes and the lack of simple, unobtrusive instruments to measure sleep quality.
7)
"Our study is one of the first of its kind in the literature because most of the research done so far has been done in sleep laboratories and in the context of other variables that could affect how well we sleep," he said.
8)
THE STUDY
Wargocki and his colleagues conducted two experiments in identical student dormitories at the Technical University of Denmark. Sixteen students took part in every two weeks.
The researchers looked at different interventions to improve the air quality in the bedrooms by increasing ventilation and monitoring carbon dioxide (CO2) levels as a marker of poor IAQ, says Wargocki.
9)
"We manipulated the ventilation rate in their bedrooms, and in the second experiment, they were unaware of the changes we made," he said. In the first experiment, which was considered a pilot, a window was opened, he said.
In the main experiment, the rooms had two conditions: increased and low ventilation (as if the windows were closed all night), each lasting one week. Each subject experienced both conditions in a counterbalanced order (i.e. 50% experienced poor air quality first).
10)
During the ventilated condition, an inaudible outside air supply fan was automatically switched on when the CO2 concentration rose above 900 ppm. The fan was switched off throughout the night during the low ventilation condition.
Students could open the windows during the day but had to remain closed at night.
11)
According to the research, the CO2 concentration in each room ranged from 1,620 ppm to 3,300 ppm with the fan off and from 795 ppm to 935 ppm with the fan on. The average CO2 concentration in the low-ventilation condition was 2,395 ppm, with an average of 835 ppm in the increased-ventilation condition.
12)
THE RESULTS
The students wore wristwatch-type actigraphs that recorded arm movements to measure how long it took them to fall asleep, how often they woke up during the night and how long they slept; this information can be used to assess how well they slept.
The following morning, within 10 minutes of waking up, students completed an online self-report questionnaire asking how well and how long they slept and other relevant questions. The students also took two online tests that measured their concentration and attention, Wargocki said.
13)
"What we observed was that when the fan was on, and the air quality improved, as indicated by a lower CO2 concentration, the students spent a greater percentage of their time in bed sleeping when the fan was on," he said, adding that these students also tended to perform better on the cognitive tests.
The students reported that the air was fresher when they got up with the fan on, and they felt better and more rested. However, Wargocki said they felt their mouths and skin were drier.
14)
Although the results were obtained with students, the researchers noted that the findings could likely be generalised to the general population and other climatic regions.
"Given these findings, it is reasonable to hypothesise that the next day's performance would be better after sleeping in conditions that provide better bedroom air quality. It has been possible to show that this is the case, and to my knowledge, this is the first time this has been done," Wargocki said.
15)
Because people spend nearly one-third of their lives in the bedroom, Wargocki believes that more research should be done on how the bedroom thermal environment and IAQ affect sleep quality. He also said that ASHRAE should play an active role in this endeavour.
