Should I open windows at night in summer?

It might seem that the Air Quality gets better at night as there is less traffic on roads and less industrial emissions. Moreover the well ventilated space induces better sleep. But is it safe to open windows at night? 

In this article we will answer all your queries regarding nighttime pollution, is it safe to open windows at night, how it affects our health.  Also we’ll suggest some pro tips to cleanse the air quality of your bedroom and how you can  keep harmful pollutants at bay. 

Should I open windows at night in summer?

No, you should not open windows in summers especially; if you live in urban areas. 

The air quality is not good at night. The reason being that at night there is less wind which allows pollutants, such as smoke, dust and particles to settle closer to the ground.

Why is the air quality unfit at night? 

The air quality gets worse at night due to atmospheric stability.  Atmospheric stability is defined as the tendency for vertical mixing of air in the atmosphere. 

Atmospheric stability can occur at any time but it is more prevalent at night. During Daytime the ground is heated by the sun with the phenomenon of convection. This results in the constant overturning and promotes vertical mixing of air. Therefore the pollutants released have a higher probability of dispersing into the atmosphere. 

At night the  land gets cooled due to loss of solar radiation. This results in air-surface temperature difference leading to a relatively stable atmosphere. This promotes higher chances of immediate environmental exposure.

This explains that a more stable atmosphere will have less potential for vertical mixing and more potential for horizontal spread.

These weather conditions are responsible for high atmospheric pollutant concentrations, particularly nitrogen oxides, ozone, etc.

The other reason is the Urban Heat Island effect. There is a difference in meteorology of urban and rural areas.

Difference in the structures and land covers leads to urban heat island effect. The cities have smaller albedo and higher heating capacity due to the presence of fabric, concrete and asphalt. There is a restricted emission of thermal radiation, especially at night. For clear skies  cities are several degrees warmer than the countryside due to urban heat island effect. And several anthropogenic activities such as vehicular emissions, industrial pollution etc are the main factors responsible for Urban Heat Island effect.

What are the health effects related to nighttime air quality?

  • There are several ways how air quality at night affect us:
  • Air pollution affect vital organs such as; lungs, heart and brain
  • Sleeping disorders like sleep apnea
  • Affects mood
  • Disrupts the REM cycle

Let us try to understand each of these in brief. 

Air quality affect our vital organs like; lungs brain and heart

Effect on lungs

  • shortness of breath
  • Coughing 
  • Wheezing
  • Asthma and chest pain
  • Lung cancer 

Effect on brain

  • Inflammation and oxidative stress 
  • Can also lead to dementia 
  • Particulate matter having size less than 2.5 (PM2.5) can enter the brain directly and can reduce cognitive function
  • PM2.5 can reduce semantic memory 
  • PM2.5 can also reduce brain volume

Effect on heart

  • Several air pollutants like ozone, NO2, CO, and particulate matter have detrimental effects on vascular system 
  • Sleep-disordered breathing and air pollution are linked together for increased risk of cardiovascular disease and low blood oxygen levels.
  • Increased episodes of cardiovascular morbidity and mortality
  • Low blood oxygen levels, and reduced quality of sleep.

Air pollution can cause sleeping disorders

  • Studies have linked sleep disorders with air pollution. The two pollutants namely PM2.5 and NO2 are believed to cause obstructive sleep apnea. 
  • Sleep apnea is caused by blockage in the upper airway causing restricted oxygen flow in the body. 
  • Air pollution damages the mucous membrane of throat and nose, which causes nasal congestion, multiplying the risk of getting sleep apnea
  • People living near power plants, industries and high traffic areas are at a greater risk of experiencing sleep apnea. 

Air pollution can disrupt REM cycles

  • Too much of Carbon dioxide plays a negative impact on our sleep quality. 
  • It is believed that people who sleep under high CO2 concentrations have their REM cycles (the state of deep sleep ) disrupted. 
  • CO2 is not harmful in small quantities but higher quantities can cause drowsiness and makes you feel groggy. 

Air pollution affect mood 

  • Air pollution has also been linked with emotional imbalance. People living in high pollution zones are likely to experience mood swings, low concentration and even memory lapse.
  •  Further people living in high pollution zones who are used to smoking are at even greater risk of sleep apnea, cardio-vascular disorders and even lung cancer. 

What Researchers say about the issue of deteriorating  Air Quality at Night ?

Recent studies have highlighted the detrimental effect of PM2.5 on the health of people in the United States. It was shown that only a 5ug/m3 of PM2.5 exposure increased the number of hospital admissions for Alzheimer’s, dementia and Parkinson’s by about 33-100%.

What can you do to improve the air quality without the need to open the windows?

You can improve the air quality at night by using or doing the below mentioned things:

Installing an HVAC system 

The HVAC system works efficiently towards filtering airborne contaminants. The filter should be upgraded on a timely basis in order to maintain its efficiency. 

Here are a few HVAC systems that you can buy: 

HVAC Systems  Honeywell Air Cleaner

  • Features: This can be operated with gas, oil and AC systems. 
  • Efficiency for capturing particles is upto 98%.
  • Has a very low pressure drop

HVAC Systems  DAIKIN Air Conditioner Heat Pump System

  • Features: Daikin’s ductless technology offers  greater  energy efficiency; cools and warms up the room fast.
  • Smart inverter technology with integrated inverted variable speed compressor
  • Provides continuous heating and cooling with minimum temperature fluctuations.
  • Quiet operation; with indoor sound levels as low as 37 decibels.

Install an air conditioning system

Apart from cooling, the air conditioners also help in ventilation by the circulation of air inside the room.The air conditioner works on a principle that it draws the warm air of the room and replaces it with cool air, thus ensuring proper air circulation. Air conditioners also help in keeping the dampness at bay.

If you are looking for some portable yet efficient air conditioners check out the below mentioned links: 

Air conditioners: whynter portable air conditioner

  • Features: It has four operational modes; AC, fan, dehumidifier and auto mode.
  • Offers an airflow rate of 300 m3/h
  • Has an eco- friendly CFC free technology
  • Dehumidifying capacity of 81 Pts/day


Use a Dehumidifier 

Dehumidifiers help extract the excessive moisture out of your room. Dehumidifier works on a two step principle:

Firstly it draws moisture out of the air and collects the water on a drip tray Secondly it warms up the collected dry and cold air and finally fan the dry air back in the room. 

Check out these links for some of the best Dehumidifiers: 

Dehumidifiers: Gocheer Upgraded Dehumidifier

  • Features: High efficiency dehumidifier 
  • Equipped with a 2000ml water tank capacity
  • It is very compact and portable
  • suitable for highly humid areas; such as the bathroom, basement, kitchen, living room etc.
  • Quiet operation of as low as 40dB
  • Comes with automatic shut off mode to prevent overflowing of water tank 
  • Saves energy with a consumption of only 1.15 kW of electricity within 24 hours of operation. 

Dehumidifiers: COSVI Upgrade Dehumidifier

  • Features: COSVI home dehumidifier keeps moisture below 35%
  • Comes with one-button switch design for easy operation
  • Offers a whisper quiet operation with sound levels below 35 dB
  • Energy efficient; consumes less energy with a power only 48W/ hour after running for 24 hours. 
  • Cost effective 
  • Comes with an auto shut feature
  • Compact and lightweight ideal for bathrooms, basements, kitchen, bedrooms etc.

Use air purifiers

The simplest way to improve nighttime air quality is to install air purifiers. Air purifiers are devices which circulate the air through a set of filters and capture the contaminants like; microscopic particles such as dust, allergens, molds, spores, bacteria, etc, that are floating around.

Nowadays there are many filters available in markets having several features like HEPA filter, Activated carbon filter, and ultraviolet light. 

Below are the best air purifiers for improving the air flow in your bedroom:

Air purifiers: HATHA SPACE air purifier

  • Features: Particle efficiency of about 99.97% for particle size 0.3-0.1 micron.
  • Effective against pollen, dust, VOCs, tobacco smoke, odors, pet hair, etc.
  • Medical grade filter
  • Good for extra large rooms
  • Auto mode available for fan speed adjustment
  • Comes with a 5 years warranty

Air purifier: LEVOIT Air Purifiers

  • Features: You can access this device from anywhere, fan speeds can be operated through your smartphone. 
  • Better purification with its 360 degree design. Suitable for large rooms. 
  • It has an ultra fine nylon pre filter and activated carbon filter. 
  • Highly efficient against 99.7% contaminants for particles as small as 0.3 microns such as; dust pollen, pet hair, mold, odor etc. 
  • Does not make much noise
  • Voice control feature

Air purifier: Germ guardian air purifier

  • Features: Particle efficiency of about 99.7% for particles as small as 0.3 microns.
  • UV C light sanitizer is effective against viruses like; staph, rhinovirus, influenza, and VOCs.
  • Effective against allergens; pet dander and other large particles. 
  • It has a carbon filter and is highly effective against odors like; smoking, pets, odor from cooking, etc. 
  • Does not make much noise 

Air purifiers: TOPPIN HEPA Air Purifiers

  • Features: Efficiency of about 95% for particle size of 0.3 microns. 
  • It has UV light, carbon filter and nano silver filter coating. 
  • Highly efficient against airborne contaminants; dust, pet hair, pollen and also efficient against odors, tobacco smoke etc. 
  • Fragrance sponge and aroma diffuser are also present. 
  • Purifies a large area of upto 160 sq ft
  • Low noise levels
  • Uv lamps are covered to avoid direct eye contact



Introduce indoor plants 

Introducing indoor plants at home not only provides 24×7 oxygen supply but also helps you sleep better. These plants are of low maintenance offering you numerous benefits. Whether it is filtering out the harmful toxins or providing you a 24×7 oxygen supply. 

So introduce the following plants into your house today and feel the difference. 

  • Snake plant or Sansevieria
  • Warneck Dracaena
  • Bamboo palm
  • Gerber Daisies or Gerbera jamesonii
  • English ivy
  • Aloe vera
  • Lavender

Other FAQs about Air Quality that you may be interested in.

Should I exercise in bad air quality?

Luminous air purifier and humidifier

Philips 2-in-1 air purifier and humidifier series 3000i


So in this article we tried  to answer all your queries regarding nighttime pollution. We saw if it is safe to open windows at night, how it affects our health.  Also we suggested some pro tips to improve the nighttime air quality of your house and how you can  keep harmful pollutants at bay. 


Is your Air Keeping You at Night

How to Sleep Better During Air Pollution Days

Understanding Air Pollution

Increased Resting Heart Rate with Pollutants in a Pollution Based City

Air Pollution Damages Brain as Well as Heart and  Lungs,microns%20%5B11%2C%2012%5D.%20%C2%A0

Air Pollution Linked To Sleep Breathing Problems

Air Quality worse at Night, Early Morning

Using Indoor Air Quality Tactics to Sleep Better at Night, Perform Well the Next Day

Leave a Comment