Chapter 34 Walters

HEPA filters can filter to a very high efficiency, down to a(n) ___ micrometers-sized particle or lower

0.3

What are the relative humidity limits recommended for residences

40%-60%

The American Society for Heating, Refrigrration, and Air Conditioning Engineers (ASHRAE) has guidelines governing indoor air quality. These guidelines are called ASHRAE Standard ___

62.1-2013

When odor is a concern, a filter containing ___ should be used

Activated charcoal

Air in homes tends to be drier in the winter. Why?

Air at lower temperatures in the winter infiltrates in the house. As this air is raised in temperature, it expands. The portion of the total volume the moisture occupies is less and the relative humidity is lower because air with higher temperatures can hold more moisture.

A house is built on property whose soil is rich in uranium. The occupants of the house may...

Be exposed to radon gas Be more susceptible to lung cancer

The atomizing humidifiers can be spray nozzle or ___ types

Centrifugal

One of the most common substances used as an absorber is...

Charcoal

___ filters gave large surface area and require a deep filter case.

Cube

A pleated filter...

Does not clog up as quickly as a standard filter Has much more surface area than non-pleated filters

How can the installation of a humidifier help to reduce heating cost

Dry air causes the person to feel cold, due to water evaporation from the skin, and to set the thermostat a few degrees higher to become comfortable, thus consuming more heating energy.

In the ionizing od an electronic air cleaner, the particles in the air are given a positive ___

Electric charge

In electric furnace as well as heat pump systems, the recommended humidifier would be a(n) ___

Electrically heated

Humidification generally relates to the process of causing water to ___ into the air

Evaporate

The humidifier should exhaust directly onto air filters and electronic air cleaners

False

People who are active and spend a great deal of time outdoors are more likely to experience the effects of pollution?

False, there is more pollution inside than outside

Because humidifiers use water, the evaporative surface and water reservoir must be cleaned and sanitized regularly to prevent the distribution of ___ by moving the airstream

Fungi Bacteria Algae

Why are HEPA filters desirable

HEPA filters are desirable since they can trap particles that can contain mold, dust mites, pollen, and bacteria

What is the major objection to using an atomizing humidifier with hard water

Hard water contains minerals that leave the water vapor as dust and will be distributed throughout the house

Electronic air cleaners generally have...

Ionizing sections Charcoal filters Prefilters

Describe atomizing humidification

It is based on the discharge of tiny water droplets into the air. This mist evaporates rapidly humidifying the air

What level of mold contamination correspond to areas from 10 to 30 sq. Ft.

Level 2

The steps to aggressively controlling the contamination of indoor air would involve...

Locating and eliminating the source of contamination Providing adequate ventilation Providing methods for cleaning

A fiberglass media air filter contains a dust-holding adhesive That helps prevent particulates from___

Migrating downstream

The controller for a humidifier or humidistat has an element that is ___ sensitive

Moisture

How does adding humidity to the air in a residence affect the thermostat setting

Raising the relative humidity of the air allows comfort levels at lower thermostat settings

Environmental tobacco smoke (ETS) is often referred to as ___

Secondhand smoke

How can humidification be provided in residences that do not have heating equipment with ductwork

Self contained humidifiers may be installed

How would you check the calibration of a humidistat

Sling psychrometer

Define relative humidity

The percent of moisture in air as compared to the amount it could hold If it were saturated.

Atomizing humidifiers discharge ___ into the air

Tiny water droplets

An atomizing humidifier should not operate when the furnace and blower are not operating

True

Caution must be used with changing from one air cleaning filter type to another. If a technician replaces a low density filter with a high density filter it is very likely that the airflow wi be reduced.

True

The air in the home feels dry when it is heated because it expands, spreading put the moisture

True

A supplemental photocatalytic oxidation filter (PCO) is often included with ___ air purifiers

UV Ultraviolet