Find the sentences where Participle II is used

ENERGY EFFICIENCY

Energy efficiency is an important feature in making a building material environmentally sustainable. The ultimate goal in using energy-efficient materials is to reduce the amount of generated energy that must be brought to a building site. The long-term energy costs of operating a building are heavily dependent on the materials used in its construction.

Depending on type, the energy-efficiency of building materials can be measured using factors such as R-value, shading coefficient, luminous efficiency or fuel efficiency. Preferred materials slow the transfer of heat through a building’s skin, reducing the need for heating or cooling. Quantitative measurements of a building material’s efficiency are
available to help in the comparison of building materials and determining appropriateness for certain installations.

• R-Value (insulation): Building envelopes are generally rated by their insulating value, known as the R-value. Materials with higher R-values are better insulators; materials with lower R-values must be used in thicker layers to achieve the same insulation value. R-values can be measured for individual materials (e.g., insulation, siding, wood paneling, brick) or
calculated for composite structural elements (e.g., roofing, walls, floors, windows). Many types of insulation materials are available, from organic cellulose made from recycled paper to petrochemical-derived foams.

• Shading Coefficient: Although daylighting is the cheapest and most pleasant form of illumination, the accompanying heat gain from direct solar radiation is not always welcome, particularly in hot climates. The shading coefficient (SC) is a ratio of the solar heat gain of a building’s particular fenestration to that of a standard sheet of double-strength glass of the same area. This allows a comparison of the sun-blocking effectiveness of various glass types, shading devices, and glazing patterns. Shading devices can be designed to block solar heat gain at certain times of the day or year: overhangs are often used to block high summer sun but admit direct light during the winter. Certain types of glass or applied films allow selective transmission of the visible radiation (light) while preventing or reducing the transmission of infrared radiation (heat).

• System Efficiency: Electrical and mechanical systems are responsible for more than 50% of a building’s annual energy costs. Heating, ventilation, and air-conditioning (HVAC) systems should be selected for the greatest efficiency at the most commonly experienced temperatures. A system that offers peak efficiency at an outdoor temperature experienced by the building’s climate only 5% of the time will not necessarily be the best choice. Regular maintenance programs are also necessary to keep equipment operating at peak efficiency.

4. Read the text once more and tell what information was new for you. Give your comments about this information.

Text 2

1. Read the text to yourself and answer the question: Why is it
so important to calculate air exchange rates?

NON-TOXIC OR LESS-TOXIC MATERIALS IN BUILDING

Non- or less-toxic materials are less hazardous to construction workers and building’s occupants. Many materials adversely affect indoor air quality and expose occupants to health hazards. Some building materials, such as adhesives, emit dangerous fumes for only a short time during and after installation; others can contribute to air quality problems throughout a building’s life.

The rush to make buildings airtight in the wake of the 1970s oil crises created a new health problem: “sick building syndrome.” This occurs when natural or artificial ventilation is inadequate to remove odors and chemicals emitted by certain building materials. These substances may be hazardous, even carcinogenic. The resins in plywood, particle board, and the chemicals used in foam insulation have been implicated in
sick building syndrome. Formaldehyde, benzene, ammonia, and other
hazardous or cancer-causing chemicals are present in many building
materials, furnishings, and cleaning solutions.

Previously, the infiltration rate of outside air through the gaps and cracks in a building’s envelope compensated for contamination of the
inside air by human respiration, bacteria or molds, and material emissions. The problem of indoor air contamination is magnified by the increasing airtightness of buildings. Superinsulating buildings in attempts to conserve energy has caused reduced air infiltration, meaning occupants are exposed to higher concentrations of toxins for longer time periods. The health
effects of these toxins must be considered when selecting materials
and calculating air exchange rates. By selecting materials with lower or nonexistent levels of these materials, environmental health problems can be avoided and the need for expensive air scrubbers reduced.

Material toxicity is of increasing concern with the growing number of building products containing petroleum distillates. These chemicals, known as volatile organic compounds (VOCs) can continue to be emitted into the air long after the materials containing them are installed. The severity of this process, called “outgassing,” is dependent on the chemicals involved, rate emission, concentration in the air, and length of exposure. Many adhesives, paints, sealants, cleaners, and other common products contain VOCs. Often, the substances are only exposed for
a short time during and after installation; the outgassing diminishes drastically or completely once the offending materials have cured or been covered by other building materials. Therefore, higher air cycling rates are recommended during installation of these materials and for several months following building occupation.

2. Read the text again and answer the questions given below:

1. What building materials can emit dangerous fumes?

2. What new health problem appeared in the wake of the 1970s?

3. Why do architects increase airtightness of buildings nowadays?

4. What are air scrubbers used for?

5. Why should air exchange rates be calculated?

6. How are building products containing petroleum distillates called?

7. What process is called “outgassing”?

8. What products contain VOCs?