Commercial solar rooftop installation is installing solar panels on the roof of a commercial building to generate electricity. Commercial solar systems are typically larger than residential ones, ranging in size from a few kilowatts to several megawatts.
The installation process typically begins with a site assessment to determine the suitability of the roof for solar panels. Factors such as roof orientation, shade, structural integrity, and available space are all considered. Once the site is deemed suitable, the solar installer will design and install a system that meets the specific needs of the building owner.
There are two main mounting systems for commercial solar panels: ballasted and attached. Ballasted systems use heavy weights, such as concrete blocks, to secure the panels to the roof. Attached systems use roof-penetrating hardware to attach the panels to the roof.
Once the mounting system is installed, the solar panels are attached. The panels are wired together in series and then connected to a solar inverter. The inverter converts the direct current (DC) electricity produced by the panels to alternating current (AC) electricity, which can power the building's electrical needs.
The final step in the installation process is to connect the solar system to the building's electrical grid. This allows the building owner to return excess electricity to the utility company.
Here is a more detailed overview of the commercial solar rooftop installation process:
Site assessment:The solar installer will visit the site and assess the roof for suitability. This includes checking the roof orientation, shade, structural integrity, and available space.
System design: The solar installer will design a system that meets the specific needs of the building owner. This includes considering the building's energy consumption, budget, and desired payback period.
Mounting system installation: The solar installer will install the mounting system supporting the solar panels.
Solar panel installation:The solar installer will attach the solar panels to the mounting system.
Solar inverter installation: The solar installer will install the solar inverter, which converts the DC electricity produced by the panels to AC electricity.
Grid interconnection:The solar installer will connect the solar system to the building's electrical grid.
Commercial solar rooftop installations can be completed in a few weeks, depending on the system's size and the installation's complexity.
Commercial solar rooftop installations offer several benefits to businesses, including:
Reduced energy costs:Solar panels can generate electricity for free, significantly reducing a business's energy costs.
Increased energy independence: Solar panels can help businesses become more independent and reduce their reliance on the utility grid.
Improved environmental performance:Solar energy is a clean and renewable energy source, which can help businesses reduce their environmental impact.
Increased property value:Commercial solar installations can increase the value of a business's property.
If you are a business owner considering a commercial solar rooftop installation, several resources are available to help you get started. You can contact local solar installers for quotes and consultations. You can also search for government and utility incentives that may be available to help offset the installation cost.
By combining a CeO2 catalyst with atmospheric carbon dioxide, researchers from Osaka City University, Tohoku University, and Nippon Steel Corporation have developed an effective catalytic process for the direct synthesis of polycarbonate diols without using dehydrating agents. Their method, published in Green Chemistry, does not rely on toxic chemical feedstock like phosgene and carbon monoxide, making it the world's first high yield "green" reaction system.
(Nanowerk News) Using a CeO2 catalyst, researchers develop an effective catalytic process for the direct synthesis of polycarbonate diols without the need for dehydrating agents. The high yield, high selective process has CO2 blown at atmospheric pressure to evaporate excess water by-product allowing for a catalytic process that can be used with any substrate with a boiling point higher than water.
CeO2 catalyzes the direct polymerization of flow CO2 and diols to provide polycarbonate diols in high yields, which are useful chemicals for polyesters, polyurethanes, and acrylic resins. (Image: Masazumi Tamura)
By combining a CeO2 catalyst with atmospheric carbon dioxide, researchers from Osaka City University, Tohoku University, and Nippon Steel Corporation have developed an effective catalytic process for the direct synthesis of polycarbonate diols without using dehydrating agents. Their method, published in Green Chemistry, does not rely on toxic chemical feedstock like phosgene and carbon monoxide, making it the world’s first high yield “green” reaction system.
There is a worldwide need to reduce carbon dioxide, one of the major greenhouse gases, and converting it into a useful chemical compound has attracted much attention in recent years. Various effective catalyst systems have been developed but they rely on toxic chemicals that churn out unmanageable by-products. Processes using substrates that are easily available and safe, with water as the only by-product, have emerged as an alternative. Yet, high levels of water by-product keep these processes from synthesizing enough polycarbonates.
"Most processes use a dehydrating agent to keep water levels low to overcome an equilibrium," said Masazumi Tamura of the Osaka City University, "but some of the issues to address are the high pressure of carbon dioxide needed, the recovery and regeneration of the dehydrating agent, and contamination of by-products generated by its use."
To bypass these issues, the research team developed a catalytic process that does not use a dehydrating agent. By focusing on the difference in boiling points between the chemical product/diol and water, the research team predicted a high carbon fixation yield by blowing in CO2 at atmospheric pressure to evaporate excess water.
“It became clear that among the metal oxide catalysts we used,” stated Keiichi Tomishige of Tohoku University, “CeO2 showed the highest activity.” This simple catalytic reaction system is the first ever to successfully synthesize polycarbonate diols from carbon dioxide and diols at atmospheric pressure. “This process, without the need of dehydrating agents, can chemically convert carbon dioxide using any substrate with a boiling point sufficiently higher than water,” concluded Kenji Nakao of Nippon Steel Corporation, “and can be applied to the synthesis of carbonates, carbamates, and ureas, which are useful additives for lithium-ion batteries and/or raw materials for polymer synthesis.”
Source: Osaka University https://www.nanowerk.com/
The selection of green building materials and products represents a critical strategy in designing a green building. Green building materials offer specific benefits to the building owner and building occupants and are as follows:
Reduced maintenance/replacement costs over the life of the building.
Energy conservation.
Improved occupant health and productivity.
Lower costs associated with changing space configurations.
Greater design flexibility.
Building and construction activities worldwide consume 3 billion tons of raw materials yearly, or 40 per cent of total global use. Using green building materials and products promotes the international conservation of dwindling nonrenewable resources.
In addition, integrating green building materials into building projects can help reduce the environmental impacts associated with the extraction, transport, processing, fabrication, installation, reuse, recycling and disposal of these building industry source materials.
Selection criteria for green material
A) Resource efficiency:
Recycled Content: Products with identifiable recycled content, including post-industrial content, with a preference for post-consumer content.
Natural and renewable: Materials harvested from sustainably managed sources preferably have an independent certification (e. g., certified wood) and are certified by an independent third party.
Resource-efficient manufacturing process: Products manufactured with resource-efficient processes include reducing energy consumption, minimizing waste (recycled, recyclable and or source-reduced product packaging), and reducing greenhouse gases.
Locally available: Building materials, components, and systems found locally or regionally save energy and resources in transportation to the project site.
Salvaged, refurbished, or remanufactured: Includes saving material from disposal and renovating, repairing, restoring, or generally improving the appearance, performance, quality, functionality, or value of a product.
6) Reusable or recyclable: Select materials that can be easily dismantled, reused, or recycled at the end of their useful life.
7) Durable: Materials that are longer lasting or are comparable to conventional products with long life expectancies.
Evaluation Criteria for Green Materials
Due to phenomenal growth in the construction industry, there is tremendous pressure on depleting earth resources such as soil, sand, stones, wood, etc. Production of building materials leads to irreversible environmental impacts. Using environmentally friendly building materials is the best way to build an eco-friendly building. The following criteria can be used to identify green materials.
Local availability of materials
The embodied energy of materials
% of recycled/waste materials used
Rapidly renewable materials
Contribution to Energy Efficiency of buildings
Recyclability of materials
Durability
Environmental Impact
Using the abovementioned criteria and assigning a particular rating (R1-R8) to each standard, an overall evaluation of the material can be made by summating the score obtained by any material in these ratings. Guidelines for assigning a rating to each criterion are discussed in the following text.
i) Local availability of materials
As far as possible, locally available materials are preferred to minimize the energy spent in transporting the building materials. Energy consumed in vehicles is the total energy spent on transporting materials starting from the place of manufacturing. Depending upon the distance from the material's manufacturing place, points for rating R1 can be allotted to the materials based on the following guidelines.
ii) The embodied energy of materials
Embodied energy assesses the energy required to manufacture any building material. This includes the energy needed to extract raw materials from nature, the energy used to transport raw materials to the manufacturing unit and the energy used in manufacturing activities to provide a finished product. Every building is a complex combination of many processed materials, each of which contributes to the building's total embodied energy. Embodied energy is a reasonable indicator of the overall environmental impact of building materials, assemblies or systems. The embodied energy of some building materials is mentioned in Table-2. Depending upon embodied energy of the materials, points for rating R2 can be allotted based on guidelines given in Table-3.
(iii) Percentage of recycled/waste materials used
Building materials can be manufactured using recycled materials or using waste materials. Using recycled materials helps the environment and the economy in several ways. A significant effect is lessening the need for manufacture with virgin, non-renewable resources, saving precious resources, energy and cost. Waste materials that would have ended up in landfills after their useful life can be reprocessed for use in other products. The use of various types of waste materials, such as fly ash, blast furnace slag, red mud, waste glass, marble dust, cinder, rice husk, coconut husk, banana leaves, jute fibres, rubber from automobile tires, etc., is demonstrated by research. Table-4 specifies guidelines for rating R3 for this criterion.
(iv) Use of renewable resources
Materials manufactured with renewable resources (i.e. wood or solar power) rather than non-renewable (i.e. fossil fuels) shall be preferred. Depletion of the Earth's resources is occurring at an alarming rate. The entire ecosystem is affected due to the continuous extraction of raw materials worldwide. As fossil fuel stock is limited, it may get exhausted very soon. By utilizing renewable energies, such as wind, solar, tidal, and renewable materials, such as wood (certain certified species which are rapidly renewable), grasses or sand, the impact on biodiversity and ecosystems can be lessened.
(v) Contribution to Energy Efficiency of buildings
Building construction and operation utilize a significant portion of the total energy produced. With little careful effort, designers and builders can reduce energy loads on structures, reducing energy requirements and the strain on natural resources. With proper orientation of the building concerning solar radiation to receive maximum daylighting, operable windows for natural cross-ventilation, use of passive cooling techniques (eliminating or lessening the need for air conditioning), walling unit with lower U values, roof insulation, water-saving devices and more efficient appliances can all work to reduce energy needs. Consideration of alternate energy source use, such as wind, solar and tidal power, can help alleviate reliance on traditional fossil fuel sources. The Bureau of Energy Efficiency (BEE) was set up by Govt. of India, which has formulated the Energy Conservation Building Code (ECBC),
which defines specific minimum energy performance standards for buildings. ECBC specifies minimum values for U-factor (U-factor is thermal transmittance which is the rate of transfer of heat through the unit area of a structure for the unit difference in temperature across the network., unit is W/m2-0C), Solar Heat Gain Coefficient (SHGC - the ratio of the solar heat gain entering the space through the fenestration area to the incident solar radiation. Solar heat gain includes directly transmitted solar heat and absorbed solar radiation, which is then reradiated, conducted, or convected into space) and Visual Transmittance (VT – it indicates the percentage of the visible portion of the solar spectrum that is transmitted through a given glass) with guidelines to be Table 6 specifies procedures for rating R5 for this criterion.
(vi) Recyclability of materials
The recyclability of the materials can be judged from the number of materials recovered for reuse after the useful life of materials/products or after the demolition of the building. Table - 7 specifies guidelines for rating R6 for this criterion.
(vii) Durability
Material replacement puts a strain on the Earth, its resources and its inhabitants. In making materials more durable and easy to maintain, manufacturers can help eliminate a costly, damaging and time-consuming process replacement process. Materials which are long-lasting and need little maintenance are preferred. Rating R7 for this criterion can be considered as mentioned in Table-8.
(viii) Environmental Impact
All materials used for the construction of buildings must not
harm the environment, pollute air or water, or cause damage to the Earth, its inhabitants and its ecosystems during the manufacturing process and also during use or disposal after the end of life. The material should be non-toxic and contribute to good indoor air quality. Worldwide industrial production uses billions of tons of raw materials every year. Pollution caubydthe by the excavation, manufacturing, use or disposal of a product can have far-reaching consequences on the Earth's ecosystem. Poor indoor air quality caused by VOC emission costs billions in medical bills and lost productivity to companies every year. The manufacturing, use, and disposal of PVC pose substantial and unique environmental and human health hazards because of its uniquely wide and potent range of chemical emissions throughout its life cycle. It is virtually the only material that requires phthalate plasticizers, which frequently include heavy metals, and emits large numbers of VOCs. In addition, during manufacture, it produces many highly toxic chemicals, including dioxins (the most potent carcinogens measured by man), vinyl chloride, ethylene dichloride, etc. When burned at the end of life, whether in an incinerator, structural fire or landfill fire, it releases hydrochloric acid and more dioxins. Products made with PVC may be avoided as far as possible. The following points should be considered for evaluating the environmental impact of the building materials, allocating ratof ing R8.
Classification of materials based on a scale
After evaluating the material for the criteria mentioned above and allocating points for rating R1-R8, totalling a maximum of 100 points, materials can be classified based on total points scored per the following guidelines.
Using the criteria, some materials are classified assuming specific data, as mentioned in Table-11.
B) Indoor Air Quality (IAQ):
Low or non-toxic: Materials that emit few or no CFCs, reproductive toxicants, or irritants, as demonstrated by the manufacturer through appropriate testing.
Minimal chemical emissions: Products with minimal emission of Volatile Organic Compounds (VOCs). Products that also maximize resources and maximize efficiency while reducing chemical emissions.
Moisture resistant: Product and systems that resist moisture or inhibit the growth of biological contaminants in the building.
Healthfully maintained: Materials, components, and systems that require only straightforward, non-toxic, or low-VOC methods of cleaning.
Systems or equipment: Products that promote IAQ by identifying indoor air pollutants or enhancing air quality.
C) Energy Efficiency:
Material, components, and systems that help reduce energy consumption in buildings and facilities.
D) Water Conservation:
Products and systems that help reduce water consumption in buildings and conserve water in landscaped areas.
E) Affordability:
Building product life-cycle costs are comparable to conventional materials and are within a project-defined percentage of the overall budget.
When selecting a site, the team must consider many attributes of the overall system:
What is the local climate of the project?
Has the site been previously developed?
Is it connected to local infrastructure and public transportation?
What species in the area might use the site as habitat and be affected?
What is the nature of street life in the area, and how can the project contribute to the community?
Where do people in the area live and work, and how do they get back and forth?
Why is this important for buildings?
The location of a building is as important as how it is built. Its connection and linkage to the local bioregion, watershed, and community will help determine how a project can contribute to a sustainable environment. A sustainable project serves more than the immediate function of the building. It must also meet the needs of the local community, support active street life, promote healthy lifestyles, provide ecosystem services, and create a sense of place.
Site selection and design play important roles in both reducing greenhouse gas emissions and helping projects adapt to the effects of climate change. If people can use public transportation, ride bicycles, or walk to the building, the project helps reduce the carbon emissions associated with commuting. A project that is connected to the community by pedestrian paths and bicycle lanes encourages people to walk or bike instead of drive, not only helping to reduce air pollution, but also promoting physical activity. Sustainable Sites
The first category of LEED prerequisites and credits has to do with the location and piece of land the project is built on. LEED Sustainable Sites credits deal with protecting natural habitat, keeping open spaces, dealing with rainwater, and heat island and light pollution reduction.
Construction Activity Pollution Prevention
This measure is required for LEED certification. It involves executing specific measures designed to limit the effect of construction activities on the surrounding environment, by containing soil erosion, sedimentation of waterways, and airborne dust. A plan must be developed that meets the requirements of the EPA 2012 Construction General Permit or local requirements, whichever is more stringent. This plan must be in effect throughout the project, with photo and inspection evidence to show that the plan was maintained.
Site Assessment
This credit is worth 1 point. In order to earn this credit, project teams must perform and document a site assessment of the project location, including the following topics: topography, hydrology, climate, vegetation, soils, human use, and human health effects. The assessment should discuss how the topics above influence the design, as well as any of the topics that were not addressed in the design.
Protect or Restore Habitat
This credit is worth 1-2 points. The project must preserve and protect at least 40% of the greenfield (undeveloped) area on the project site if such an area exists. In addition, the project must restore 30% of the site to natural habitat using native and adapted plant species (worth 2 credits), or provide financial support to an organization accredited by the Land Trust Alliance (worth 1 credit). The habitat restoration should include both soil and vegetation, and vegetated roofs can be counted in certain circumstances.
Indoor air quality (IAQ) in I-BEAM refers to the quality of the air inside buildings as represented by concentrations of pollutants and thermal (temperature and relative humidity) conditions that affect the health, comfort and performance of occupants. Other factors affecting occupants, such as light and noise, are essential indoor environmental quality considerations but are not treated in I-BEAM as core elements of indoor air quality.
Why is IAQ Important to Building Managers?
Buildings exist to protect people from the elements and to otherwise support human activity. Buildings should not make people sick, cause them discomfort, or otherwise inhibit their ability to perform. How effectively building functions to support its occupants and how efficiently the building operates to keep costs manageable is a measure of the building's performance.
The growing proliferation of chemical pollutants in consumer and commercial products, the tendency toward tighter building envelopes and reduced ventilation to save energy, and pressures to defer maintenance and other building services to reduce costs have fostered indoor air quality problems in many buildings. Occupant complaints of odours, stale and stuffy air and symptoms of illness or discomfort breed undesirable conflicts between occupants or tenants and building managers. Lawsuits sometimes follow.
If indoor air quality is not well managed daily, remediation of ensuing problems and/or resolution in court can be extremely costly. So it helps to understand the causes and consequences of indoor air quality and to manage your building to avoid these problems.
Occupant Symptoms Associated with Poor Indoor Air Quality
Human responses to pollutants, climatic factors and other stressors such as noise and light are generally categorised according to the type and degree of reactions and the time frame in which they occur. Building managers should be usually familiar with these categories, leaving detailed knowledge to health and safety professionals.
Acute Effects: Acute effects are those that occur immediately (e.g., within 24 hours) after exposure. Chemicals released from building materials may cause headaches, or mould spores may result in itchy eyes and runny noses in sensitive individuals shortly after exposure. Generally, these effects are not long-lasting and disappear soon after exposure ends. However, exposure to some bio-contaminants (fungi, bacteria and viruses) resulting from moisture problems, poor maintenance or inadequate ventilation has been known to cause serious, sometimes life-threatening respiratory diseases which themselves can lead to chronic respiratory conditions.
Chronic Effects: Chronic effects are long-lasting responses to long term or frequently repeated exposures. Long term exposures to even low concentrations of some chemicals may induce chronic effects. Cancer is the most commonly associated long term health consequence of exposure to indoor air contaminants. For example, long term exposure to the following increases cancer risk:
environmental tobacco smoke
radon
asbestos
benzene
Discomfort: Discomfort is typically associated with climatic conditions, but building contaminants may also be implicated. People complain of being too hot or too cold or experience eye, nose or throat irritation because of low humidity. However, reported symptoms can be challenging to interpret. Complaints that the air is "too dry" may result from irritation from particles on the mucous membranes rather than low humidity, or "stuffy air" may mean that the temperature is too warm or there is lack of air movement, or "stale air" may mean that there is a mild but difficult to identify odour. These conditions may be unpleasant and cause discomfort among occupants, but there is usually no serious health implication involved. Absenteeism, work performance and employee morale, however, can be seriously affected when building managers fail to resolve these complaints.
Performance Effects: Significant measurable changes in people's ability to concentrate or perform mental or physical tasks have been shown to result from modest changes in temperature and relative humidity. Besides, recent studies suggest that similar effects are associated with indoor pollution due to lack of ventilation or the presence of pollution sources. Estimates of performance losses from poor indoor air quality for all buildings suggest a 2-4% loss on average. Future research should further document and quantify these effects.
Building Associated Illnesses
The rapid emergence of indoor air quality problems and
associated occupant complaints have led to terms which describe illnesses or
Effects particularly associated buildings. These include:
Sick Building Syndrome
Building-Related Illness
Multiple Chemical Sensitivity
Sick Building Syndrome (SBS): Sick Building Syndrome (SBS)
is a catch-all term that refers to a series of acute complaints for which there
is no apparent cause and where medical tests reveal no particular abnormalities.
The symptoms display when individuals are in the building but disappear when
they leave.
Complaints may include such symptoms as:
irritation of the eyes, nose and throat
headache
stuffy nose
mental fatigue
lethargy
skin irritation
These complaints are often accompanied by non-specific
Complaints such as the air are stuffy or stale. A single causative agent (e.g.,
contaminant) is seldom identified, and charges may be resolved when building
operational problems and/or occupant activities identified by investigators are
Corrected. Experience in resolving SBS complaints has led to many of the
suggestions for "good practice" found in I-BEAM.
The likely outcomes
of SBS problems which are not quickly resolved to include:
increased absenteeism
reduced work efficiency
deteriorating employee morale
Building-Related Illness (BRI): Building related illness
refers to a defined disease with a known causative agent resulting from
Exposure to the building air. While the causative agent can be chemical (e.g.,
Formaldehyde), it is often biological. Typical sources of organic
contaminants are:
humidification systems
cooling towers
drain pans or filters
other wet surfaces
water damaged building material
Symptoms may be specific or mimic symptoms commonly
Associated with the flu, including fever, chills and cough. Serious lung and
Respiratory conditions can occur. Common examples of building-related illness
include:
Legionnaires' disease
hypersensitivity pneumonitis
humidifier fever
Multiple Chemical Sensitivity (MCS): It is generally
recognised that some persons can be sensitive to particular agents at levels
Which do not have a noticeable effect in the general population? Besides,
it is recognized that certain chemicals can be sensitisers in that exposure to
the compound at high levels can result in sensitivity to that chemical at much
lower levels.
Some evidence suggests that a subset of the population may
be especially sensitive to low levels of a broad range of chemicals at levels
typical in today's home and working environments. This apparent condition has
come to be known as multiple chemical sensitivity (MCS).
Persons reported having MCS apparently have difficulty
being in most buildings. There is significant professional disagreement
concerning whether MCS actually exists and what the underlying mechanism might
be. Building managers may encounter occupants who have been diagnosed with MCS.
Resolution of complaints in such circumstances may or may not be possible with
the guidance provided in I-BEAM. Responsibility to accommodate such individuals
is subject to negotiation and may involve arrangements to work at home or in a
different location.
Building Factors Affecting Indoor Air Quality
Factors Affecting Indoor Climate
The thermal environment (temperature, relative humidity and
airflow) are essential dimensions of indoor air quality for several reasons.
Many complaints of poor indoor air may be resolved by simply
altering the temperature or relative humidity
Thermally uncomfortable people will have a lower
tolerance to other building discomforts.
The rate at which chemicals are released from building
materials are usually higher at higher building temperatures.
Thus, if occupants are too warm, it is also likely that they
are being exposed to higher pollutant levels.
Indoor thermal conditions are controlled by the heating,
Ventilating, and air conditioning (HVAC) system. How well the thermal
the environment is managed depends on the design and operating parameters of The system, and on the heat gains and losses in the space being controlled. These
gains and losses are principally determined by:
indoor sources of heat
the heat gains from sunlight
the heat exchange through the thermal envelope
the outdoor conditions and outdoor air ventilation rate
Factors Affecting Indoor Air Pollution
Much of the building fabric, its furnishings and equipment,
Its occupants and their activities produce pollution. In a well functioning
the building, some of these pollutants will be directly exhausted to the outdoors
and some will be removed as outdoor air enters the building and replaces the
Air inside. The air outside may also contain contaminants which will be brought
Inside in this process. This air exchange is brought about by the mechanical
introduction of outdoor air (outdoor air ventilation rate), the automatic
the exhaust of indoor air and the air exchanged through the building envelope
(infiltration and exfiltration).
Pollutants inside can travel through the building as air
flows from areas of higher atmospheric pressure to regions of lower atmospheric
pressure. Some of these pathways are planned and deliberate to draw
pollutants away from occupants, but problems arise when unintended flows bring
contaminants into occupied areas. Besides, some pollutants may be removed
from the air through natural processes, as with the adsorption of chemicals by
surfaces or the settling of particles onto surfaces. Removal processes may also
be deliberately incorporated into the building systems. Air filtration devices,
for example, are commonly incorporated into building ventilation systems.
Thus, the factors most important to understanding indoor
pollution are:
indoor sources of pollution,
outdoor sources of pollution,
ventilation parameters,
airflow patterns and pressure relationships, and
air filtration systems.
Types of Pollutants
Common pollutants or pollutant classes of concern in commercial buildings along with conventional sources of these pollutants are provided below.
Table 1.1 Indoor Pollutants and Potential Sources
Pollutant or Pollutant Class
Potential Sources
Environmental Tobacco Smoke
Lighted cigarettes, cigars and pipes
Combustion Contaminants
Furnaces, generators, gas or kerosene space heaters, tobacco products, outdoor air and vehicles
Biological Contaminants
Wet or damp materials, cooling towers, humidifiers, cooling coils or drain pans, damp duct insulation or filters, condensation, re-entrained sanitary exhausts, bird droppings, cockroaches or rodents, dust mites on upholstered furniture or carpeting, or body odours.
Particleboard, plywood, cabinetry, furniture and fabrics
Soil gases (radon, sewer gas, VOCs, methane)
Soil and rock (radon), sewer drain leak, dry drain traps, leaking underground storage tanks, and landfills
Pesticides
Termiticides, insecticides, rodenticides, fungicides, disinfectants and herbicides
Particles and Fibers
Printing, paper handling, smoking and other combustion, outdoor sources, deterioration of materials, construction/renovation, vacuuming, and insulation
Contaminant Sources
Indoor Sources
Identified below are some sources of contaminants commonly found in office buildings and offers some measures for maintaining control of these contaminants. Follow these measures to help maintain a healthy indoor environment.
Category/Common Sources
Housekeeping and Maintenance (Includes) -
cleansers
waxes and polishes
disinfectants
air fresheners
adhesives
janitor's/storage closets
wet mops
drain cleaners
vacuuming
paints and coatings
solvents
pesticides
lubricants
Tips for Mitigation and Control
Use low-emitting products
Avoid aerosols and sprays.
Dilute to proper strength (manufacturer's instructions)
Do not overuse; use during unoccupied hours.
Use proper protocol when diluting and mixing.
Store properly with containers closed and lid tight
Use exhaust ventilation for storage spaces (eliminate return air)
Clean mops: store mop top-up to dry
Avoid “air fresheners”—clean and exhaust instead.
Use high-efficiency vacuum bags/filters
Use Integrated Pest Management
Occupant-Related Sources (Includes)
Tobacco products
Office equipment (e.g., Printers and copiers)
cooking/microwave
art supplies
marking pens
paper products
personal products (e.g., perfume)
tracked in dirt/pollen
Tips for Mitigation and Control
Smoking policy
Use exhaust ventilation with pressure control for primary local sources.
Low emitting art supplies/marking pens
Avoid paper clutter
Education material for occupants and staff
Building Uses as Major Sources (Includes)
print/photocopy shop
dry cleaning
science laboratory
medical office
hair/nail salon
cafeteria
pet store
Tips for Mitigation and Control
Use exhaust ventilation and pressure control
Use exhaust hoods where appropriate; check hood airflows.
Building-Related Sources (Includes)
plywood/compressed wood
construction adhesives
asbestos products
insulation
wall/ floor coverings (vinyl/plastic)
carpets/carpet adhesives
wet building products
transformers
upholstered furniture
renovation/remodeling
Tips for Mitigation and Control
Use low emitting products.
Air out in the open/ventilated area before installing
Increase ventilation rates during and after installing
Keep material dry before enclosing.
Use renovation guidelines
HVAC system (Includes)
contaminated filters
contaminated duct lining
dirty drain pans
humidifiers
lubricants
refrigerants
mechanical room
maintenance activities
combustion appliances (e.g., boilers/furnaces, DHW, generators and stoves)
Tips for Mitigation and Control
Perform HVAC preventive maintenance
Use filter change protocol.
Clean drain pans; proper slope and drainage
Use potable water for steam humidification.
Keep duct lining dry; move to line outside of duct if possible.
Fix leaks/clean spills (see filter change protocol)
Maintain spotless mechanical room (not a storage area)
Avoid back drafting
Check/maintain flues from the boiler to outside
Keep combustion appliances properly tuned.
Disallow unvented combustion appliances
Perform polluting activities during unoccupied hours
Moisture (Includes)
mould
Tips for Mitigation and Control
Keep building dry
Mould and Moisture Control Protocol
Vehicles (Includes)
Underground/attached garage
Tips for Mitigation and Control
Use exhaust ventilation
Maintain garage under negative pressure relative to the building
Check airflow patterns frequently
Monitor CO
Outdoor Sources
Identified below are familiar sources of contaminants that are introduced from outside buildings. These contaminants frequently find their way inside through the building shell, openings, or other pathways to the inside.
Ambient Outdoor Air (Includes)
air quality in the general area
Tips for Mitigation and Control
Filtration or air cleaning of the intake air
Vehicular Sources (Includes)
local vehicular traffic
vehicle idling areas
loading dock
Tips for Mitigation and Control
Locate air intake away from the source
Require engines shut off at loading dock
Pressurise building/zone
Add vestibules/sealed doors near the source.
Commercial/Manufacturing Sources (Includes)
laundry or dry cleaning
restaurant
photo-processing
automotive shop/gas station
paint shop
electronics manufacturer/assembly
various industrial operations
Tips for Mitigation and Control
Locate air intake away from the source
Pressurise building relative to outdoors
Consider air cleaning options for outdoor air intake.
Use landscaping to block or redirect the flow of contaminants, but not too close to air intakes.
Utilities/Public Works (Includes)
utility power plant
incinerator
water treatment plant
Tips for Mitigation and Control
Locate air intake away from the source
Pressurise building relative to outdoors
Consider air cleaning options for outdoor air intake.
Use landscaping to block or redirect the flow of contaminants, but not too close to air intakes.
Agricultural (Includes)
pesticide spraying
processing or packing plants
ponds
Tips for Mitigation and Control
Locate air intake away from the source
Pressurise building relative to outdoors
Consider air cleaning options for outdoor air intake.
Use landscaping to block or redirect the flow of contaminants, but not too close to air intakes.
Construction/Demolition Tips for Mitigation and Control
Pressurise building
Use walk-off mats
Building Exhaust (Includes)
bathrooms exhaust
restaurant exhaust
air handler relief vent
exhaust from the major tenant (e.g., dry cleaner)
Tips for Mitigation and Control
Separate exhaust or relief from the air intake
Pressurise building
Water Sources (Includes)
pools of water on the roof and cooling tower mist
Tips for Mitigation and Control
Proper roof drainage
Separate air intake from the source of water
Treat and maintain cooling tower water.
Birds and Rodents (Includes)
faecal contaminants and bird nesting
Tips for Mitigation and Control
Bird proof intake grills
Consider vertical grills
Use Integrated Pest Management
Building Operations and Maintenance (Includes)
trash and refuse area
chemical/fertilisers/grounds keeping storage
painting/roofing/sanding
Tips for Mitigation and Control
Separate source from the air intake
Keep source area clean/lids on tight.
Isolate storage area from occupied areas
Ground Sources (Includes)
soil gas
sewer gas
underground fuel storage tanks
Tips for Mitigation and Control
Depressurise soil
Seal foundation and penetrations to foundation
Keep air ducts away from ground sources.
Protocols for Managing Major Sources of Pollution in Buildings
Type of Protocol
Solution
Remodelling and Renovation
Use effective strategies for material selection and installation.
Isolate construction activity from occupants.
Painting
Establish a protocol for painting and ensure that the contract is followed by both in-house personnel and by contractors.
Use low VOC emission, fast-drying paints where feasible.
Paint during unoccupied hours.
Keep lids on paint containers when not in use.
Ventilate the building with significant quantities of outside air during and after painting. Ensure a complete building flush before occupancy.
Use more than normal outside air ventilation for some period after occupancy.
Avoid spraying, when possible.
Pest Control Integrated Pest Management
Use or require the use of Integrated Pest Management by pest control contractors to minimise the use of pesticides when managing pests.
Control dirt, moisture, clutter, foodstuff, harborage and building penetrations to minimise pests.
Use baits and traps rather than pesticide sprays where possible.
Avoid periodic pesticide application for “prevention” of pests.
Use pesticides only where pests are located.
Use pesticide formulated explicitly for the targeted pest.
Apply pesticides only during unoccupied hours.
Ventilate the building with significant quantities of outside air during and after applications.
Ensure a complete building flush before occupancy.
Use more than normal outside air ventilation for some period after occupancy.
Notify occupants before occupation.
If applying outside, keep away from the air intake.
Shipping and Receiving
Establish and enforce a program to prevent vehicle contaminants from entering the building.
Do not allow idling of vehicles at the loading dock. Post signs and enforce the ban.
Pressurise the receiving area relative to the outside to ensure that contaminants from the loading area do not enter the building. Use pressurised vestibules and airlocks if necessary.
Periodically check the pressure relationships and compliance with the protocol.
Notify delivery company supervisors of policy.
Establish and Enforce a Smoking Policy
Environmental tobacco smoke (ETS) is a major indoor air contaminant. A smoking policy may take one of two forms:
A smoke-free policy which does not allow smoking in any part of the building.
A policy that restricts smoking to designated smoking lounges only.
(Partial policies such as allowing smoking only in private offices are not effective.)
Smoking Lounge Requirements
A designated smoking lounge must have the following features to be effective in containing ETS.
The lounge should be fully enclosed.
The lounge should be sealed off from the return air plenum.
The lounge should have exhaust ventilation directly to the outside at 60cfm per occupant (using maximum occupancy).
Transfer air from occupied spaces may be used as makeup air.
The lounge should be maintained under negative pressure relative to the surrounding occupied spaces.
Managing Moisture and Mold (See also EPA's Mold Remediation Guidelines)
Mold thrives in the presence of water. The secret to controlling mould is to control moisture and relative humidity.
Keep relative humidity below 60% (50%, if feasible, to control dust mites)
Keep all parts of the building dry that is not designed to be wet.
Adequately insulate exterior walls or ceilings to avoid condensation on cold surfaces.
Insulate cold water pipes to avoid sweating
Clean spills immediately. Thoroughly clean and dry liquid spills on porous surfaces such as carpet within 24 hours, or discard the material.
Do not allow standing water in any location.
Maintain proper water drainage around the perimeter of the building
Provide sufficient exhaust in showers or kitchen areas producing steam
Thoroughly clean areas that are designed to be wet
Wash floors and walls often where water accumulates (e.g., showers)
Clean drain often pans and insures a proper slope to keep water draining
Ensure proper maintenance and treatment of cooling tower operations
Discard all material with signs of mould growth
Discard furniture, carpet, or similar porous material having a persistent musty odour.
Discard furniture, carpet, or similar porous material that has been wet for more than 24 hours
Discard ceiling tiles with visible water stains
Pollution Transport
Air Movement and Pressure: Contaminants reach occupant breathing-zones by travelling from the source to the occupant by various pathways. Usually, contaminants go with the flow of air.
Air moves from areas of high pressure to areas of low pressure. That is why controlling building air pressure is an integral part of controlling pollution and enhancing building IAQ performance.
Air movement should be from occupants, toward a source and out of the building rather than from the source to the occupants and out the building. Pressure differences will control the direction of air motion and the extent of occupant exposure.
Driving Forces: Driving forces change pressure relationships and create airflow. Conventional driving forces are identified in the table below.
Major Driving Force
Effect
Wind
Positive pressure is created on the windward side, causing infiltration, and negative influence on the leeward side, causing exfiltration, though wind direction can be varied due to surrounding structures.
Stack Effect
When the air inside is warmer than outside, it rises, sometimes creating a column of rising air -- up stairwells, elevator shafts, vertical pipe chases etc. This buoyant force of the wind results in positive pressure on the higher floors and a negative influence on the lower levels and a neutral pressure plane somewhere between.
HVAC/Fans
Fans are designed to push air in a directional flow and create positive pressure in front, and negative pressure behind the fan.
Flues and Exhaust
Exhausting air from a building will reduce the building air pressure relative to the outdoors. Air exhausted will be replaced either through infiltration or through planned outdoor air intake vent.
Elevators
The pumping action of a moving elevator can push air out of or draw air into the elevator shaft as it moves.
Common Airflow Pathways
Contaminants travel along pathways - sometimes over great distances. Trails may lead from an indoor source to an indoor location or from an outside source to an indoor area.
The location experiencing a pollution problem may be close by, in the same or an adjacent area. Still, it may be a considerable distance from, and/or on a different floor from a contaminant source.
Knowledge of common pathways helps to track down the source and/or prevent contaminants from reaching building occupants.
Common Airflow Pathways for Pollutants
Common Pathway
Comment
Indoors
Stairwell
Elevator shaft
Vertical electrical or plumbing chases
The stack effect brings about airflow by drawing air toward these chases on the lower floors and away from these chases on the higher levels, affecting the flow of contaminants.
Receptacles, outlets, openings
Contaminants can quickly enter and exit building cavities and thereby move from space to space.
Duct or plenum
Contaminants are commonly carried by the HVAC system throughout the occupied spaces.
Duct or plenum leakage
Duct leakage accounts for significant unplanned airflow and energy loss in buildings.
The flue or exhaust leakage
Leaks from sanitary exhausts or combustion flues can cause serious health problems.
Room spaces
Air and contaminants move within a room or through doors and corridors to adjoining spaces.
Outdoors to Indoors
Indoor air intake
Polluted outdoor air or the exhaust air can enter the building through the air intake
Windows/doors, Cracks and crevices
A negatively pressurised building will draw air and outside pollutants into the building through any available opening.
Substructures and slab penetrations
Radon and other soil gases and moisture-laden air or microbial contaminated air often travel through crawlspaces and other substructures into the building.
Ventilation
Ventilation can be used to either exhaust pollutants from a fixed source, or dilute contaminants from all sources within a space.
Exhaust Ventilation: Ideally, exhaust airflow should be sufficient to draw pollutants from the source into the exhaust and away from occupants. The source should be located between the exhaust and the occupants. Rooms with significant sources should be under negative pressure relative to the surrounding spaces. Some sources, such as cooking stoves and laboratory benches, may require exhaust hoods. Also, see Exhaust Systems.
Dilution Ventilation: Contaminants from area sources such as people, building materials, office equipment, are diluted with outdoor air from natural or mechanical ventilation. Ventilation systems should be operated to provide sufficient outdoor air ventilation. Reducing outdoor air ventilation rates below required levels saves little energy and is not advisable. If capacity is available, outdoor air ventilation rates should meet applicable standards under all operating conditions. Problems with reduced outdoor air during part-load in specific VAV systems should be addressed.
Ventilation Measurements: Measurement instruments and techniques, which are generally available to building personnel, can be extremely useful in assessing the performance of the right ventilation system for both exhausting and diluting pollutants. Useful measuring tools include:
Smoke tube to measure airflow
Flow hood to measure air volume
Velocity meter to measure air velocity
Measuring carbon dioxide to estimate the percentage of outdoor air or to generally evaluate outdoor air ventilation
