Fresh air is an important standard to measure indoor air quality. It affects air circulation and indoor air pollution.
Fresh air is useful for two purposes:
One is to reduce the concentration of harmful substrates, reach the hygiene standard. Taking CO2 as an example, its average standard value is 0.1%. The second is to supplement indoor air ventilation and keep indoor positive pressure.
According to national Indoor Air Quality Standard GB/T18883-2002, indoor fresh air value should be guaranteed not less than 30 cubic meters per house per person.
Fresh air not only affects human health, but also energy consumption, initial investment and operational cost. Lack of fresh air will cause “indoor syndrome”, headaches, palpitation, feeling fatigue and/or tiredness, illnesses on...Read more
There are many sources of indoor air pollution in any building. These include combustion sources such as oil, gas kerosene, coal, wood, and tobacco products; building materials and furnishings as diverse as deteriorated, asbestos-containing insulation, wet or damp carpet, and cabinetry or furniture made of certain pressed wood products; products from cleaning and maintenance, personal care, or hobbies; central heating and cooling systems and humidification devices; and outdoor sources such as radon, pesticides and outdoor air pollution.
The relative importance of any single source depends on how much of a particular pollutant is given off and how hazardous those emissions are. In some cases, factors such as how old the source is and whether it is properly maintained are...Read more
The term “HVAC system” is used to refer to the equipment that can provide heating, cooling, filtered outdoor air, and humidity control to maintain comfort conditions in a building. Not all HVAC systems are designed to accomplish all of these functions. Some buildings rely on only natural ventilation. Others lack mechanical cooling equipment (AC), and many function with little or no humidity control.
The features of the HVAC system in a given building will depend on several variables:
- Age of the design
- Building codes in effect at the time of the design
- Budget that was available for the project
- Planned use of the building
- Owners’ and designers’ individual preferences
- Subsequent modifications
Basic Components of an HVAC System
The basic components of an HVAC...Read more
The same Heating, Ventilating, Air Conditioning (HVAC) system that distributes conditioned air throughout a building can distribute dust and other pollutants, including biological contaminants. Dirt or dust accumulation on any components of an air handling system – its cooling coils, plenums, ducts, and equipment housing – may lead to contamination of the air supply.
There is widespread agreement that building owners and managers should take great precautions to prevent dirt, high humidity, or moisture from entering the ductwork. At the same time, there is less agreement about what measures to clean up are appropriate or how effective cleaning techniques are at making long-term improvements to the air supply or at reducing occupant complaints.
The presence of dust in ductwork...Read more
The US Environmental Protection Agency (EPA) states that indoor air is anywhere from 2 to 10 times more hazardous than outdoor air. With people spending an average of 90% of their time inside, indoor air pollution can pose a serious health risk. “Indoor air quality is the number one environmental health problem in the United States”, according to the EPA.
The American College of Allergies states that 50% of all illness is aggravated or caused by polluted indoor air.
A recent study found that the allergen level in super-insulated homes is 200% higher than it is in ordinary homes.
According to Scientific America, a baby crawling on the floor inhales the equivalent of 4 cigarettes a day, as a result of the out-gassing of carpets, molds, mildews, fungi, dust mites, etc.
The EPA...Read more
The knowledge and need to keeping your air conditioning equipment clean will continue to reward you for years to come. Educating yourself on things like cleaning the air conditioning unit, having a professional service the air conditioning unit, and general maintenance are all the keys to success.
One major reason for keeping your air conditioning equipment clean is it is extremely important for the health of your loved ones using it, a clean living space, and all around elimination of air pollutants.
Cleaning your air conditioning equipment hasn’t ever shown a 100% prevention of health problems, but it has shown that dust particle levels truly increase in the home. When your air conditioning equipment is dirty, it manifest things like mould, fungi, bacteria and other air borne...Read more
The Kingdom Fungi is a diverse kingdom consisting of over 1 million species and includes mushrooms, moulds, and yeasts. Fungi obtain their nutrition from the breakdown and decay of organic matter. They can thrive in many places such as soil, plant litter, wood, live plants, dung, animal remains, fungal remains, etc, and play a vital role in the environment as a decomposer of dead-plant matter.
Commonly called mildew, moulds (sometimes referred to as "black mould"), are a subset of fungi that produce fluffy or powdery growth on surfaces. Toxic moulds can grow on cloth, carpets, leather, wood, sheetrock, insulation (and on human foods) when moist conditions exist.
Moulds are found everywhere. The most common form of fungus on earth, and may grow at high...Read more