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Friday, November 29, 2019

குபேரன் லிங்கம்

குபேரன் லிங்கம் தரிசனம் செல்ல முடியாதவர்கள் தரிசித்து ஷேர் பண்ணலாம்...

குபேர கிரிவலத்தை முன்னிட்டு திருவண்ணாமலை கிரிவலப்பாதையில் குபேரலிங்கம் முன்பு லட்சக்கணக்கான பக்தர்கள் தரிசனம்

குபேர கிரிவலத்தை முன்னிட்டு திருவண்ணாமலை கிரிவலப்பாதையில் உள்ள குபேரலிங்கம் முன்பு லட்சக்கணக்கான பக்தர்கள் திரண்டனர். சிவபெருமானின் பஞ்சபூத தலங்களில் அக்னி தலமாக போற்றப்படும் திருவண்ணாமலையில் பவுர்ணமி கிரிவலம் வருவது சிறப்பு.

கார்த்திகை மாதம் சிவராத்திரி அன்று மாலை 6 மணி முதல் 7 மணி வரை குபேர லிங்கத்திற்கு குபேரர் வந்து சூட்சமாக பூஜை செய்வார் என்பதும், அதன் பின்னர் குபேரர் கிரிவலம் செல்வார் என்பதும், குபேரர் பூஜை செய்வதை கண்டால் வீட்டில் செல்வம் பெருகும் என்பதும் ஐதீகம்.

இதையொட்டி திருவண்ணாமலை கிரிவலப்பாதையில் உள்ள குபேர லிங்கத்திற்கு சிறப்பு அலங்காரம் மற்றும் பூஜை செய்யப்பட்டது.

Tuesday, November 26, 2019

Materials Selection for Green Buildings

The selection of green building materials and products represents one important strategy in the design of a green building. Green building materials offer specific benefits to the building owner and building occupants and are 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 each year or 40 per cent of total global use. Using green building materials and products promotes the conservation of dwindling nonrenewable resources internationally.
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:
  1. Recycled Content: Products with identifiable recycled content, including post-industrial content with a preference for post-consumer content.
  2. Natural and renewable: Materials harvested from sustainably managed sourced and preferably have an independent certification (e. g. certified wood) and are certified by an independent third party.
  3. Resource-efficient manufacturing process: Products manufactured with resource-efficient processes including reducing energy consumption, minimizing waste (recycled, recyclable and or source reduced product packaging), and reducing greenhouse gases.
  4. Locally available: Building materials, components, and system found locally or regionally saving energy and resources in transportation to the project site.
  5. 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 and 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 depletable earth resources such as soil, sand, stones, wood, etc. Production of building materials leads to irreversible environmental impacts. Using environment–friendly building materials is the best way to build an eco-friendly building. Following criteria can be used to identify the green materials.
  1. Local availability of materials
  2. The embodied energy of materials
  3. % of recycled/waste materials used
  4. Rapidly renewable materials
  5. Contribution in Energy Efficiency of buildings
  6. Recyclability of materials
  7. Durability
  8. Environmental Impact
Using the above-mentioned criteria and assigning a certain rating (R1-R8) to each of the criteria, overall evaluation of the material can be made by summation of score obtained by any material in these ratings. Guidelines for assigning a rating to each criterion is discussed in the following the text.
i) Local availability of materials

As far as possible locally available materials are to be preferred so as to minimize the energy spent in the transportation of the building materials. Energy consumed in transportation should be considered as total energy spent on transporting materials starting from the place of manufacturing. Depending upon distance from the place of manufacturing of the material, points for rating R1 can be allotted to the materials, based on following guidelines.
ii) The embodied energy of materials

Embodied energy is an assessment of the energy required to manufacture any building material. This includes the energy required to extract raw materials from nature, 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. Use of recycled materials helps the environment and the economy in several ways. A significant effect is that of lessening the need for manufacture with virgin, non-renewable resources, which saves precious resources, energy and cost. Waste materials that would have ended in landfills after its useful life, instead can be reprocessed for use in other products. Use of various type 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 resources that are renewable (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 from the earth. As a stock of fossil fuel is limited, it may get exhausted very soon. By utilizing renewable energies, such as wind, solar, tidal, as well as renewable materials, such as wood (certain certified species which are rapidly renewable), grasses or sand, impact on biodiversity and ecosystems can be lessened.
(v) Contribution in Energy Efficiency of buildings

Construction and operation of buildings utilizing a major portion of the total energy produced. With little careful efforts, designers and builders can reduce energy loads on structures, reducing energy requirements and the strain on natural resources. With proper orientation of building with reference to 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 lessen energy needs. Consideration of alternate energy source use, such as wind, solar and tidal power, can help alleviate reliance on traditional fossil fuel sources. Bureau of Energy Efficiency (BEE) has been set up by Govt. of India, who has formulated Energy Conservation Building Code (ECBC), 
which is defining certain minimum energy performance standard for buildings. ECBC specifies minimum values for U-factor (U-factor is thermal transmittance which is the rate of transfer of heat through unit area of a structure for unit difference in temperature across the structure., 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 the space) and Visual Transmittance (VT – it indicates percentage of visible portion of solar spectrum that is transmitted through a given glass) with guidelines to be Table 6 specifies guidelines 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 re-use 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

Materials which are long-lasting and needing little maintenance are preferred. Material replacement puts a strain on the earth, its resources and inhabitants. In making materials more durable and easy to maintain, manufacturers can help in eliminating a costly, damaging and time-consuming process of replacement. 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 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 caused in 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, frequently includes heavy metals and emits large numbers of VOCs. In addition, during manufacture, it is responsible for the production of a large number of 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. Following points should be considered for evaluating the environmental impact of the building materials, allocating rating R8.

Classification of materials based on a scale

After evaluating the material for the above-mentioned criteria and allocating points for rating R1-R8, totalling maximum to 100 points, materials can be classified based on total points scored, as per the following guidelines.

Using the criteria some of the materials are classified assuming certain data as mentioned in Table-11.
B) Indoor Air Quality (IAQ):
  1. Low or non -toxic: Materials that emit few or no CFC’s, reproductive toxicants, or irritants as demonstrated by the manufacturer through appropriate testing.
  2. Minimal chemical emissions: Products that have minimal emission of Volatile Organic Compounds (VOCs). Products that also maximize resources and energy efficiency while reducing chemical emissions.
  3. Moisture resistant: Product and systems that resist moisture or inhibit the growth of biological contaminants in building.
  4. Healthfully maintained: Materials, components, and systems that require only simple, non-toxic, or low-VOC methods of cleaning.
  5. 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 building and facilities.
D) Water Conservation:
Products and systems that help reduce water consumption in building 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.

Wednesday, November 20, 2019

Sustainable Sites Green Building

What factors are at play when choosing a site?

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.

1868ல் எடுத்தது. ஶ்ரீவில்லிபுத்தூர் திருக்கோவில் கோபுரம்.

பிரிட்டிஷ் லைப்ரரியில் உள்ள படம்

Monday, November 18, 2019

Construction waste

Construction activities can generate large amounts of waste materials that then need to be disposed of. In addition, at the end of a building's life, it may be deconstructed or demolished, generating significant amounts of waste. Construction waste includes the waste that is generated during construction activities (such as packaging, or the products of demolition) and materials that are surplus to requirements (as a result of over-ordering or inaccurate estimating).

Typical construction waste products can include:

Insulation and asbestos materials.
Concrete, bricks, tiles and ceramics.
Wood, glass and plastic.
Bituminous mixtures, coal tar and tar.
Metallic waste (including cables and pipes).
Soil, contaminated soil, stones and dredging spoil.
Paints and varnishes.
Adhesives and sealants.
Increasingly, there are options available in terms of reusing and recycling materials, and reducing the amount of waste produced in the first place, but despite this, a large amount of construction waste is still disposed of in a landfill. 32% of landfill waste comes from the construction and demolition of buildings and 13% of products delivered to construction sites are sent directly to the landfill without having being used (ref. Technology Strategy Board)

This can be an expensive process, as the 1996 Finance Act introduced a tax on waste disposal on all landfill sites registered in the UK. 
To help tackle this, a site waste management plan (SWMP) can be prepared before construction begins, describing how materials will be managed efficiently and disposed of legally during the construction of the works, and explaining how the re-use and recycling of materials will be maximised. For more information, see Site waste management plan.

It may be possible to eliminate a certain amount of construction waste through careful planning. For example, steel formwork systems might be capable of being used for concrete works which can then be reused elsewhere on the project/s in place of timber formwork which is classed as waste once it has been used.

Other types of construction waste may be capable of being minimised; for example, products which are provided with reduced packaging or those which are composed of recycled materials. There can also be opportunities to re-use materials and products which are in a suitable condition (e.g. doors, windows, roof tiles and so on), or exchange them for other materials with a different construction site.

Materials and products which cannot be eliminated, minimised or reused may have to be disposed of as waste. Before sending waste for disposal, it should be sorted and classified to allow waste contractors to manage it effectively and ensure that hazardous waste is properly handled.
The Problem
Disposal of public fill at public filling areas and mixed construction waste at sorting facilities or landfills has been the major approach for construction waste management. For sustainable development, we can no longer rely solely on reclamation to accept most of the inert construction waste. As such, the government is examining ways to reduce and also to promote the reuse and recycling of construction waste. Nevertheless, there will still be a substantial amount of materials that require disposal, either at public fill reception facilities or at landfills.
Today, we are running out of both reclamation sites and landfill space. With the current trend, our landfills will be full in mid to late-2010s, and public fill capacity will be depleted in the near future. In 2013, the mixed construction waste accounts for about 25% of the total waste intake at the three existing landfills. If there are insufficient public fill capacity and waste reduction measures being implemented, more public fill would probably be diverted to landfills and the landfill life will be further shortened.

ஐயப்பன் விரத விதிமுறைகள்.

1-முதன் முறை மாலை அணியும் பக்தர் கன்னி ஸ்வாமி என அழைப்பார்கள்.2-ஜந்து அல்லது ஏழு முறை மாலையணிந்து மலைக்குச் சென்றவாராயும், ஜயப்பனின் விரதமுறையை நன்கு உணர்ந்தவராயும்,பொறுமையும் ஆசாரசீலராகவும் உள்ள ஒருவரை குருஸ்வாமியாய் ஏற்று தாய்,தந்தையரை வணங்கி குருவின் கையால் மாலை அணிதல் வேண்டும்.
3.அவரவர் வசதிக்கேற்ப குருவிற்கு தட்சணை கொடுத்து குருவின் அனுக்கிரகத்தை பெறல் வேண்டும். கொடுக்கும் தட்சணை ஒரு ரூபாயனாலும் குரு ஐயப்பனே தந்ததாக அன்புடன் ஏற்றுக்கொள்ள வேண்டும்.

4.கார்த்திகை 1ம் தேதி மாலையணிதல் வேண்டும். ஒரு மண்டலம் எனப்படும் 48 நாட்கள் விரதமிருத்தல் வேண்டும். காலை உணவை விடுத்து மதியஉணவை ஜயப்பனிற்கு நிவேதனம் செய்து உண்ணவேண்டும். மாலை பால்,பழம்,பலகாரம் உண்ணலாம்.

5.விரதகாலத்தில் மிக இறுக்கமாக பிரம்மச்சரியத்தை கடைப்பிடிக்கவேண்டும். மனதளவில் கூட பெண்களை நினைத்துப் பார்க்க கூடாது. திருமணமானவர்கள் குடும்ப வாழ்வில் (இந்த நாட்களில் ஈடுபடக்கூடாது). மனதால் ஜயப்பனை மட்டும் நினைத்து அவன் பாதம் சரணடைய வேண்டும்.

6.உருத்திராட்சம் அல்லது துளசிமாலை 54 அல்லது 108 மணிகள் உடையதாக வாங்கி,அதில் ஐயப்பன் பதக்கம் ஒன்றையும் சேர்த்து அணிதல் வேண்டும்.துணை மாலை ஒன்றையும் சேர்த்து அணிதல் வேண்டும்.

7.விரதகாலத்தில் கறுப்பு,நீலம்,பச்சை நிறமுள்ள ஆடைகளை அணியவேண்டும்.கன்னி ஸ்வாமிகள் கறுப்பு மட்டும்தான் அணியலாம்.

8.காலை,மாலை குளிர்ந்த நீரில் குளித்து விட்டு ஐயப்பனிற்கு துளசி,பால்,பழம்,கற்கண்டு போன்றவற்றில் ஒன்றை நிவேதனம் செய்து 108 சரணம் சொல்லி வழிபடவேண்டும்.

9.விரதகாலத்தில் முடிவெட்டிக் கொள்ளுதல், முகச்சவரம் செய்தல் என்பன கூடாது.காலணி,குடை,மழைக்கு போடும் கவசம் என்பவற்றை தவிர்க்கவேண்டும்.மது அருந்துதல்,பொய் பேசுதல்,மாமிசம் உண்ணுதல்,கோபம் கொள்ளுதல்,கடும் சொற்கள் பேசுதல் என்பன கூடாது.

10.விரதகாலத்தில் எவருடன் பேச நேர்ந்தாலும் பேச தொடங்கும் போதும் பேசி முடிக்கும் போதும் “ஸ்வாமி சரணம்” கூறவேண்டும். மாலையணிந்தால் விரதம் பூர்த்தியாக முன்னர் அதை எக்காரணம் கொண்டும் அதை கழட்டகூடாது.நெருங்கிய உறவினரின் இறப்பால் தீட்டு நேர்ந்தால் மாலையை கழற்றி ஐயப்பன் படத்தில் போட்டு விடவேண்டும்.பின்னர் மறுவருடம் தான் மாலை அணியலாம்.

11.விரதகாலத்தில் பகலில் தூங்ககூடாது.இரவில் பாய்,தலையணை என்பவற்றை தவிர்த்து வஸ்திரத்தை விரித்து தூங்க வேண்டும்.

12.மாலையணிந்த பின் சந்திக்கும் ஆண்களை “ஐயப்பா” என்றும் பெண்களை “மாளிகைப்புறம்” என்றும் சிறுவர்களை “மணிகண்டன்” என்றும் சிறுமிகளை “கொச்சி” என்றும் அழைக்கவேண்டும்.

13.மாதவிலக்கான பெண்களை பார்ப்பது, அவர்கள் தயாரிக்கும் உணவை உண்பது கூடாது.மாதவிலக்கான பெண்களை அறியாமல் பார்க்க நேர்ந்தால் நீராடி 108 சரணம் கூறி வழிபடவேண்டும்.

14.மலைக்கு யாத்திரை புறப்பட சில நாட்களுக்கு முன்னர் விரிவான முறையில் பஜனை,கூட்டுவழிபாடு,பூஜை முதலியன நடத்தி எல்லோருக்கும் பிரசாதம் வழங்கி உணவளிக்க வேண்டும்.

15.இருமுடிக்கட்டு பூஜையை குருசாமி வீட்டிலோ,கோவிலிலோ நடத்தலாம்.கணபதியை பிரார்த்தித்து பெற்றோரை வணங்கி,ஐயப்பன் நாமத்தை சொல்லிக்கொண்டே கட்டு நிறைக்க வேண்டும்.

16.யாத்திரை புறப்படும் போது ஐயப்பன்மார்கள் போய் வருகின்றேன் என்றோ,தன்னுடன் வரும் ஐயப்பன்மார்களை வசதியாக அழைத்துச்செல்வதாகவோ,தன்னுடன் தைரியமாக வரலாம் என்றோ கூறக்கூடாது.

17.யாத்திரை புறப்படும் போது இருமுடியை தலையில் தாங்கி,வீட்டு வாசலில் ஐயப்பனை பிரார்த்தித்துக்கொண்டு தேங்காயை உடைத்து விட்டு சரணம் சொல்லி, போய்வருகிறேன் என எதுவும் கூறாது திரும்பிப் பார்க்காது செல்ல வேண்டும்.

18.யாத்திரை புறப்பட்டதில் இருந்து கன்னி சாமிமார்கள் இருமுடியை தாமக ஏற்றிக்கொள்ளவோ,இறக்கவோ கூடாது.குருசாமியின் கையாலோ அல்லது பலமலை சாமியின் கையாலோ கொண்டு தான் அதை செய்யவேண்டும்.

19.பம்பையில் நீராடி,மறைந்த முன்னோர்க்கு பித்ருதர்ப்பணம் செய்யலாம்.யாத்திரை முடிந்துதும் பிரசாதங்களை ஏந்தி வந்து,வீட்டு வாசலில் தேங்காய் உடைத்துவிட்டு வீட்டிற்குள் சென்று பூஜை அறையில் பூஜை செய்து கற்பூர ஆராத்தி காட்டி,இருமுடி அரிசியை பொங்கி எல்லோருக்கும் கொடுக்கவேண்டும்.

20. 12 வயதிற்கு கீழ்ப்பட்ட சிறுமிகளும் ருதுகாலம் நின்ற பெண்களும் மட்டுமே சபரிமலைக்கு மாலை போட்டு விரதம் மேற்கொள்ளலாம்.
21.விரதகாலத்தில் மாலை போட்ட சாமிமார்களின் வீடுகளை தவிர வேறெந்த வீட்டிலும் ஐயப்பன்மார்கள் உணவருந்தக்கூடாது.

22.மாலைபோட்ட சாமிமார்கள் அதிலும் கன்னிசாமிமார்கள் மிகவும் கண்டிப்பாக பெருவழிப்பாதையில் செல்லவேண்டும்.

23.யாத்திரை நிறைவு பெற்றதும் குருநாதர் மூலம் மாலையை கழற்றி ஐயப்பன் திருவுருவப் படத்திற்கு அணிவித்து விட்டு ஐயப்பனை பாடித்துதிப்போமாக.

+++++++++ஸ்வாமியே சரணம் ஐயப்பா+++++++*

Saturday, November 16, 2019

A Woman from Florida Recovers from Breast Cancer with Trial Vaccine

A North Florida woman is the first to ever be treated for breast cancer using an experimental vaccine. Doctors at the Mayo Clinic in Jacksonville said Lee Mercker's tumour began to recede and her immune system responded to the vaccine. She still underwent a double mastectomy to ensure the cancer was completely removed. Two more women in the early stages of breast cancer have signed up for the trial. While not a cure, doctors say the treatment shows potential as a less-invasive option than surgery or chemotherapy.

Friday, November 15, 2019

Roopa Pai a Computer Engineer the Gita and Vedas for Kids and Seekers

After the four-year project ended, the scientific-minded Roopa wrote an entertaining science book for kids, What If Earth Stopped Spinning? (2014) And then Vatsala asked her a question which went on to change her life.
Roopa's own new book, From Leeches to Slug Glue: 25 Explosive Ideas that Made  (and Are Making) Modern Medicine (Puffin) takes her back to the world of science, narrating the history of medicine for kids.

A computer engineer from Bengaluru, married to an IIT-IIM graduateand  having travelled and  lived around the world with him – from Delhi and Mumbai to New York, London and Orlando – the last thing Roopa Pai would have imagined in her youth was becoming an authority on the  Bhagavad Gita, Vedas and Upanishads, and writing books about them.She dismisses modern-day debates on who the Aryans were. “How does it matter? Those who are secure about the truth have no need to argue. Studying the scriptures has changed me. It’s made me
 less judgemental, and more at peace with diverse ideas and viewpoints. 
Instead, I keep asking myself, 
who am I?”
Mindfulness is a quality one must work on, avers Roopa,
 but it is one that also comes with a caveat. “Yes, it’s empowering
to be aware of your actions, but it’s also terrifying because now
 you must take responsibility for all the consequences as well,”
 she explains.
Our religion is certainly not for the faint of heart.

Wednesday, November 13, 2019

Everything you need to know about Indoor Air Quality in Buildings

What is Indoor Air Quality?

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
stuffy nose
mental fatigue
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 ClassPotential Sources
Environmental Tobacco SmokeLighted cigarettes, cigars and pipes
Combustion ContaminantsFurnaces, generators, gas or kerosene space heaters, tobacco products, outdoor air and vehicles
Biological ContaminantsWet 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.
Volatile Organic Compounds (VOCs)Paints, stains, varnishes, solvents, pesticides, adhesives, wood preservatives, waxes, polishes, cleansers, lubricants, sealants, dyes, air fresheners, fuels, plastics, copy machines, printers, tobacco products, perfumes, and dry cleaned clothing
FormaldehydeParticleboard, 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
PesticidesTermiticides, insecticides, rodenticides, fungicides, disinfectants and herbicides
Particles and FibersPrinting, 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

  1. 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
  2. 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
  3. 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.
  4. 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
  5. 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
  6. Moisture (Includes)
    • mould
    Tips for Mitigation and Control
    • Keep building dry
    • Mould and Moisture Control Protocol
  7. 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.
  1. Ambient Outdoor Air (Includes)
    • air quality in the general area
    Tips for Mitigation and Control 
    • Filtration or air cleaning of the intake air
  2. 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.
  3. 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.
  4. 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.
  5. 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.
  6. Construction/Demolition
    Tips for Mitigation and Control 
    • Pressurise building
    • Use walk-off mats
  7. 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
  8. 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.
  9. 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
  10. 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
  11. 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.
  • 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
  • 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 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