How Skipping HVAC Maintenance Can Affect Indoor Air Quality

Journal of Industrial Mathematics, 2016

This paper presents a methodology for assessing and monitoring the cleaning state of a heating, ventilation, and air conditioning (HVAC) system of a building. It consists of a noninvasive method for measuring the amount of dust in the whole ventilation system, that is, the set of filters and air ducts. Specifically, it defines the minimum amount of measurements, their time table, locations, and acquisition conditions. The proposed method promotes early intervention on the system and it guarantees high indoor air quality and proper HVAC working conditions. The effectiveness of the method is proved by some experimental results on different study cases.

Journal of Surgery and Medicine, 2019

Clean air is one of the essential preconditions of life. Approximately 4.3 million people die due to indoor air pollution every year. The majority of these deaths are due to stroke (34%), ischemic heart disease (26%), and chronic obstructive pulmonary disease (22%). The principal indoor air pollutant particulate materials are carbon monoxide, tobacco smoke, formaldehyde and volatile organic compounds, nitrogen dioxide, asbestos, radon, and biological pollutants (micro-organisms and allergens). The prevention of indoor air pollution and use of clean energy sources must be regarded as an opportunity to improve health, particularly that of mothers and children, reduce poverty, and achieve environmental sustainability.

Aerobiologia, 2011

Indoor environments play important roles in human health. The health hazards posed by polluted indoor environments include allergy, infections and toxicity. The term 'sick building syndrome' (SBS) describes causes of building occupants experiencing adverse health effects that appear to be linked to the time spent in a building. Questionnaire-based data were collected from the people who live or work in air-conditioned (A/C) rooms. Responses of the occupants were analyzed to understand the practices contributing to biotic pollution of indoor air-conditioned environments. Our survey revealed some interesting facts about the users of A/C rooms and their practices that may be contributing to the indoor air quality. The allergy complaints and use of antiallergy medicines were noted commonly among the occupants of government (Govt.) organizations and computer training centers where cleaning of room and A/C filters were not done periodically. Cleaning practices may reduce the complaints.

The ambient air and the micro-climate of a living environment is the most important factor directly interacting with the human body and affecting its healthy status. Indoor air cleaning is one of the most viable technological options to ensure sufficient IAQ. We have investigated the performance of in-room air cleaners in simulated real indoor conditions. The removal efficiency of ultrafine, coarse particles, and total volatile organic compounds from cigarette smoke and hair spray were investigated is association with several ventilation rates. A strong relationship was found between power of cleaner and concentration decay rate of particulate matter and gaseous pollutants; although the decay of TVOC concentrations was ~ 2 to 4 times lower than that of particles. In general, in-room air cleaners were found to be more efficient tools for indoor air quality management (represented by aerosol particle and TVOC concentrations) compared to ventilation alone.

Women and Health, 2000

Issues in Environmental Science and Technology, 2020

The inside story: Health effects of indoor air quality on children and young people Glossary Some of the terms used in this report may be unfamiliar to readers. There are brief descriptions in the text; this glossary is intended as a helpful reference point and to provide some additional context. Ammonia At room temperature ammonia is a gas. It is found in many cleaning products and in tobacco smoke. Outdoor sources such as industry and agriculture can also contribute to exposure indoors. Animal and biological pollutants Indoor allergens include those from house dust mites (HDM), cat, dog, cockroach and mouse allergens. Mould and fungi are also found indoors and can reduce air quality. These pollutants are found in the air, dust and on furniture. Carbon dioxide Carbon dioxide (CO 2) concentrations are used to assess the adequacy of ventilation in rooms and buildings. High levels of CO 2 are a sign of inadequate ventilation and may have cognitive effects such as reduced ability to concentrate. CO 2 in indoor air is also influenced by the levels outdoors. This atmospheric CO 2 has been increasing in recent decades, in part due to the use of fossil fuels, and is a significant factor in climate change. Carbon monoxide Carbon monoxide (CO) is a colourless and odourless highly poisonous gas, formed from the incomplete combustion of fuels. Common sources include cooking and heating appliances, vehicle emissions, and smoking. Endocrine disrupting chemicals Endocrine Disrupting Chemicals (EDCs) are generally synthetic compounds and interfere with human hormones. They are found in pesticides, personal care and cleaning products, household items and a range of materials including paints. Indoors these are often present in dust and in the air. See also 'semi-volatile organic compounds'. Endotoxin Endotoxin is shed from bacteria and can be found indoors in the dust or the air. Studies often look at endotoxin alongside β-d-glucan, a marker for bacteria or mould in the home. Flame retardants Flame retardants are substances added to combustible materials to stop or slow fire. The term is based on the function as the chemicals used are quite diverse. They are used to treat a variety of building materials and furnishings. Some flame retardants are known to be Endocrine Disrupting Chemicals. One type, Polybrominated Diphenyl Ethers (PBDEs), is no longer produced in the EU. The inside story: Health effects of indoor air quality on children and young people Formaldehyde Formaldehyde is a naturally occurring gas and produced synthetically for a wide range of uses. It is present in many building materials, furniture, coatings and finishes, and household products. It is also found in tobacco smoke, produced in chemical reactions, and can be emitted through cooking. Nitrogen oxides Nitric oxide (NO) and nitrogen dioxide (NO 2) are key components of outdoor air pollution. Together they are often referred to as NO X and are a product of combustion. Sources include motor vehicles, energy production, and industry. Indoor air quality is affected by outdoor NO X coming inside. Indoor pollution (NO 2 in particular) can be caused by burning gas, oil, paraffin, coal or wood. Tobacco smoking and candles are also sources. Ozone Ozone (O 3) can be produced when sunlight reacts with pollutant mixtures in the atmosphere. At ground-level it is a significant air pollutant and, like other outdoor air pollutants, also enters buildings. Ozone can also be produced by some devices such as printers, photocopiers and some air cleaning appliances. Ozone reacts with other indoor air pollutants. In contrast, ozone in the stratosphere protects against ultraviolet rays and became depleted through the use of Chlorinated Fluorocarbons (CFCs) which are now banned. Particulate matter Particulate matter (PM) is suspended droplets and inhalable solid particles found in the air, in dust, or on surfaces. PM is usually classified into three categories. These are grouped by the maximum diameter in micrometres: inhalable particles (PM 10), fine particles (PM 2.5), and ultrafine particles (UFP). UFP have a diameter of less than 0.1 micrometre. The chemical composition of PM in the air changes depending on the source of the particles. Major indoor PM sources include outdoor air, smoking, cooking, burning (fires, stoves, candles, and incense), cleaning and people. Per-and poly-fluorinated alkyl substances Per-and poly-fluorinated alkyl substances (PFAS) are a group of manufactured chemicals. These chemicals do not break down, and they can stay in the human body for a long time. PFAS are used as stain or water repellents on a wide range of products, and in non-stick coatings. They have been found in air and dust samples indoors. Pesticides or insecticides Pesticides and insecticides are mainly used outdoors but can contribute to indoor air quality through air, soil or other particles entering the home. Indoor uses include to control pests in the home, on pets, and for houseplants. There are a range of diverse chemicals used, including organophosphates (halogenated and non-halogenated). Phenols Phenols are a type of synthetic, water-soluble chemical (organic phenol is commonly found in foods). Indoors, phenols are found in cleaning products, polishes, paints and adhesives. Phenols can also be released by burning wood, fuels or tobacco. The inside story: Health effects of indoor air quality on children and young people Polycyclic Aromatic Hydrocarbons Polycyclic Aromatic Hydrocarbons (PAHs) are a subset of Volatile Organic Compounds. PAHs are formed from incomplete combustion of organic matter. Indoors this means key sources are outdoor air, cooking, and burning wood, coal or tobacco. PAHs include benzene, benzo-a-pyrene, naphthalene, toluene, and xylenes. See also 'Volatile Organic Compounds'. Volatile Organic Compounds Volatile Organic Compounds (VOCs) are emitted from a very wide range of indoor and outdoor sources. This happens through combustion and from the use of products such as paints, coatings or pesticides; VOCs can vaporise into the air from the source materials. Total VOCs (TVOCs) is used as a measure of the combined concentration of VOCs.

Building and Environment, 2010

Poor indoor air quality has been linked to the exacerbation of asthma symptoms in children. Because people spend most of their time indoors, improving indoor air quality may provide some relief to asthma sufferers. A study was conducted to assess whether operating an air cleaning/ventilating unit (HEPAiRx Ò ) in a child's bedroom can improve his/her respiratory health. Thirty children diagnosed with asthma were randomly split into two groups. For the first six weeks, group A had the air cleaning/ventilating unit (HEPAiRx Ò ) running in the bedrooms of the participants and group B did not; for the second six weeks, both groups had the cleaners running in the bedrooms; and, for the final six weeks, group A turned the cleaners off and group B kept theirs running. Indoor air quality parameters, including temperature, relative humidity, particulate matter (PM 0.5-10 mm), carbon monoxide, carbon dioxide and total volatile organic compound (TVOC) concentrations, were monitored in each bedroom using an AirAdvice indoor air quality multi-meter. As a measure of pulmonary inflammation, exhaled breath condensate (EBC) was collected every sixth day and analyzed for nitrate and pH. Peak expiratory flow (PEF) was also measured. PM and TVOC concentrations decreased with operation of the HEPAiRx an average of 72% and 59%, respectively. The EBC nitrate concentrations decreased significantly and the EBC pH and PEF values increased significantly with operation of the unit (p < 0.001 when comparing on/off sample means). These results indicate that air cleaning in combination with ventilation can effectively reduce symptoms for asthma sufferers.

Indoor Air, 2014

Retail stores contain a wide range of products that can emit a variety of indoor pollutants. Among these chemicals, phthalate esters and polybrominated diphenyl ethers (PBDEs) are two important categories of semivolatile organic compounds (SVOCs). Filters in heating, ventilation, and airconditioning (HVAC) system collect particles from large volumes of air and thus potentially provide spatially and temporally integrated SVOC concentrations. This study measured six phthalate and 14 PBDE compounds in HVAC filter dust in 14 retail stores in Texas and Pennsylvania, United States. Phthalates and PBDEs were widely found in the HVAC filter dust in retail environment, indicating that they are ubiquitous indoor pollutants. The potential co-occurrence of phthalates and PBDEs was not strong, suggesting that their indoor sources are diverse. The levels of phthalates and PBDEs measured in HVAC filter dust are comparable to concentrations found in previous investigations of settled dust in residential buildings. Significant correlations between indoor air and filter dust concentrations were found for diethyl phthalate, di-n-butyl phthalate, and benzyl butyl phthalate. Reasonable agreement between measurements and an equilibrium model to describe SVOC partitioning between dust and gas-phase is achieved.

Journal of Advanced Nursing, 2005