Test/Quiz 3
Passive and low-energy approaches for control of IAQ addresses the issue in the following manner:
"The solution to pollution is dilution."
A ________ relative humidity change will affect a person's comfort about as much as a 2 degree F change in temperature.
30%
The exhaust capacity of a principal residential building exhaust fan should be at least ________ of the total HVAC system airflow capacity.
50%
Which intersection of relative humidity and air temperature is outside the ASHRAE thermal comfort zone?
60% and 88 degrees Fahrenheit (30 degrees Celsius)
Which of the following ASHRAE standards address ventilation and IAQ in residential building?
ASHRAE 62.2
Which compound can be used as a "canary in the coal mine" to warn of the buildup of other pollutants?
CO2
Mean radiant temperature can be defined as the average apparent temperature experienced by all individuals in a room.
False
Media filters are considered the least effective filter type for cleaning air.
False
The most important method of providing acceptable IAQ is to maintain the building and equipment in clean condition.
False
The recommended low humidity limit for the ASHRAE thermal comfort zone is 10%.
False
The three categories of factors that affect comfort include personal, measurable environmental, and ________.
Psychological
Name the missing environmental (nonphysical) parameter that shapes thermal comfort: dry-bulb air temperature, relative humidity, ________ , air speed.
Radiant temperature
Match the indoor air pollutant with its source(s).
Radon - natural radioactivity in soils Ozone - laser printers, photocopiers Formaldehyde - particle board, glues Carbon monoxide - furnaces, stoves, fireplaces Carbon dioxide - human respiration Lead - pre-1970s paint
Heat exchange from the body to its surrounding environment can occur via four means of heat flow. These types of heat flow are: conduction, convection, radiation, evaporation.
True
The ASHRAE thermal comfort zones, as plotted on a psychometric chart, are primarily defined by relative humidity and operative temperature.
True
A clo is a unit that measures the insulating value of clothing. A single clo is equivalent to which of the following:
a business suit
"Sick building syndrome" is best described as:
a collection of ailments that seems to be associated with occupancy of a building
ASHRAE has defined "acceptable" indoor air quality as:
air in which there are no harmful concentrations of known contaminants and with which 80% of people exposed to not express dissatisfaction
An increase in occupancy can directly result in an increase in:
carbon dioxide (CO2)
Which of the following, non-environmental, thermal comfort parameters can be most easily adjusted?
clothing
The heat transfer process of ________ is primarily dependent on a difference in surface temperatures.
conduction
Fresh air brought directly into a space during the winter will improve IAQ and may:
decrease thermal comfort
These two measurements are necessary in order to derive relative humidity:
dry-bulb temperature and wet-bulb temperature
The psychometric chart shows the relationship of:
dry-bulb temperature, wet-bulb temperature, RH
As air temperatures approach those of our own body, this mechanism for heat flow becomes essential:
evaporation
"Operative" temperature is best described as:
including the effects of dry bulb and mean radiant temperatures
The most common energy source for regenerating desiccant cooling devices today is:
natural gas
At the rate of 1 air change per hour (ACH) of outdoor air, an indoor space would have:
only 63% "new" air after 1 hour
The "adaptive" model of thermal comfort suggests that:
people can be expected to take actions to improve their own thermal comfort
Which of the following best describes the sources of pollutants normally found in buildings?
processes, equipment, occupants, finishes, and furnishings
Which of the following best describes the general approaches to providing good IAQ?
source control, filtration, exhaust, dilution, and maintenance
ASHRAE (Standard 55-2010) defines thermal comfort as:
that condition of mind which expresses satisfaction with the thermal environment
"Ventilation" is best described as:
the introduction of outdoor air into a building
The "met" is a unit of measure that is related to:
the level of activity in which a person in engaged
The following information can be found on manufacturer-provided material safety data sheets (select all that apply):
the material's chemical constituents; physical data such as melting point, flashpoint, etc.; handling procedures
Outgassing as an IAQ concern refers to:
the release of volatile organic compounds by finishes and furnishings
Problems with poor indoor air quality in buildings seem to be increasing because:
we spend more time indoors - in tighter buildings with more artificial materials
At 100% relative humidity:
wet-bulb temperature is equal to dry-bulb temperature
For the best diffusion of incoming air throughout a building, an air-to-air heat exchanger should operate under which condition?
with the exchanger located at a central forced-air fan
