ANSI/ASHRAE Standard 55 is the American Standard that establishes the ranges of environmental conditions to achieve the optimal thermal comfort inside buildings. The Standard is assessed by subjective evaluation and defines the best indoor temperature for user satisfaction ranges between 20 to 22ºC (68 to 72 ºF).
Barometric pressure affects to dew point and water condensation and is also related to the air flows causing bacteria, dust and other airborne pollutants. If air pressure in the room is lower than outside, contamination from the room does not flow out into surrounding areas. Otherwise, higher pressure inside a room, will keep out pollutants.
A high relative humidity decreases sweating effectiveness in its body temperature control function, so more sweat is produced is temperature goes high, generating discomfort and sultriness. A low relative humidity cause dryness and itching. Optimal comfort is achieved with a relative humidity in the 30-60% range.
Carbon Monoxide is a silent killer. It cannot be sawn or smelled. CO are in the air whenever fuel or other carbon-based materials are bunt. CO can cause dizziness, headaches, vomits and finally death. Event at low levels, long term exposition to CO can cause chronical hearth diseases and/or EPOC. New-borns, infants, pregnant women, elderly and people affected with respiratory diseases are the top-risk
Vehicles, gas stoves, barbecues, generators and poorly maintained ventilation equipment are the most common CO sources at indoor locations.
Breathing becomes more difficult as carbon dioxide levels rise, causing tiredness and making harder to get focused. Rest and sleep quality are also affected by CO2. In closed areas, high levels of carbon dioxide can lead to health complaints such as headaches.
Volatile Organic Compounds (VOCs) are usual components in many building materials such as plywood, glues, paintings and personal care products (perfume, hair-sprays, lacquer, burnishes, etc.). Other VOC sources are burning gases, wood or tobacco. Exposure to VOCs can cause eye, nose and throat irritation, shortness of breath, headaches, fatigue, nausea, dizziness and skin problems. Higher concentrations may cause irritation of the lungs, as well as damage to the liver, kidney, or central nervous system. Long-term exposure may also cause damage to the liver, kidneys or central nervous system. People affected with asthma are more exposed to VOCs effects.
PM2.5 (particles less than 2.5 micrometers in diameter) can penetrate deeply into the lung, irritate and corrode the alveolar wall, and consequently impair lung function. PM2.5 may therefore be capable of carrying various toxic stuffs, passing through the filtration of nose hair, reaching the end of the respiratory tract with airflow and accumulate there by diffusion, damaging other parts of the body through air exchange in the lungs. The elderly and those with pre-existing cardiopulmonary problems are more exposed to PM2.5 effects.
Exposure to high concentrations of PM10 can result in health impacts ranging from coughing and wheezing to asthma attacks and bronchitis to high blood pressure, heart attack, strokes and premature death. The young and old and persons with existing medical conditions are most likely to be adversely affected by exposure to high PM10 concentrations.