Health and Safety

Question 1

What are hydrocarbon combustion fuels?

Answer 1

Fuels like natural gas, propane, oil, and wood, that are composed of hydrogen and carbon. During combustion, oxygen combines with hydrocarbons, splitting the molecules and releasing heat.

Question 2

What are the byproducts of combustion?

Answer 2

Carbon dioxide, water vapor, carbon monoxide (byproduct of incomplete combustion), oxygen, heat, and NO2, SO2, VOCs

Question 3

What is spillage?

Answer 3

The release of combustion of by-products from combustion appliances during operation.

Question 4

What is backdrafting?

Answer 4

Continuous spillage at a flue

Question 5

What causes carbon monoxide release?

Answer 5

Incomplete combustion

Question 6

Describe carbon monoxide.

Answer 6

Colorless, odorless, undetectable by senses - CO blocks oxygen to the brain and vital organs

Question 7

What are the most effective solutions to handle dust?

Answer 7

Source control - don’t generate dust, cleaning, effective HVAC filters

Question 8

What are some common VOC sources?

Answer 8

Combustion, solvents and cleaners, paints, furniture, drapery and carpet, gasoline

Question 9

Where does radon come from?

Answer 9

Rocky soil

Question 10

What is Asbestos?

Answer 10

A known carcinogen if inhaled. Comes from pipe insulation, floor tile, siding and roofing

Question 11

What’s the number one enemy of buildings?

Answer 11

Water

Question 12

What is capillary seepage?

Answer 12

Liquid water moving through tiny spaces. It redistributes water from liquid sources.

Question 13

Water vapor moves in what two ways?

Answer 13

Through air movement and vapor diffusion. Diffusion movement depends on the permeance of the object and the vapor pressure difference.

Question 14

What are some sources of liquid water in buildings?

Answer 14

Roof leaks, malfunctioning gutters, poor site drainage, undetected plumbing leaks

Question 15

When do ice dams occur?

Answer 15

When snow melts and refreezes at a cold eave forcing water under the roofing and into building. They are a heat leakage problem, not roof.

Question 16

Water vapor always flows from…

Answer 16

high pressure to low pressure (wet to dry)

Question 17

_________ drives vapor diffusion through a difference in absolute humidity on two sides.

Answer 17

Vapor pressure

Question 18

T/F: Water vapor is smaller and lighter than air.

Answer 18

True

Question 19

What is relative humidity?

Answer 19

The percentage of the max moisture that air at a given temperature can hold. At 100% TH, air is saturated with moisture and condensation will occur with any additional moisture.

Question 20

As air cools, its relative humidity _____.

Answer 20

increases

Question 21

Condensation problems increase with:

Answer 21

Increase in absolute humidity

Decrease in temperature

Question 22

A bathroom fan should have a CFM rating that provides ___ _______.

Answer 22

8 ACH (Air changes per hour)

Question 23

Year-round natural ventilation should only occur in the following locations:

Answer 23

Attics and crawl spaces

Question 24

Most codes require 1 square foot of vent for every ____ square feet of attic area.

Answer 24

150

Question 25

Should crawlspaces be vented?

Answer 25

No, they should be closed and conditioned.

Question 26

How does and air conditioner work?

Answer 26

By passing indoor air over a cold coil, condensing water vapor and removing latent heat. ACs produce cool dry air.

Question 27

How does a dehumidifier work?

Answer 27

Dehumidifiers pass indoor air over a cold coil but then pass the same air over the warm coil. They produce warm dry air.

Question 28

What are some effective interior air barriers?

Answer 28

Drywall, concrete, plywood, and Tyvek

Question 29

What are some effective exterior air barriers?

Answer 29

Concrete, plywood, some rigid insulation boards, weather resistant barriers (felts, tyvek)

Question 30

What’s a vapor barrier?

Answer 30

A barrier that prevents water vapor from diffusing into building cavities. Exp. polyethylene sheeting, vapor-barrier paint

Question 31

What are the two primary strategies for ventilation?

Answer 31

Ventilation through air leakage and mechanical systems

Question 32

What are 3 types of mechanical whole-house ventilation?

Answer 32

Exhaust, supply, balanced

Question 33

How does a central exhaust ventilator work?

Answer 33

It pulls air out of rooms and exhausts it outdoors. Make-up air infiltrates through air leaks in the building shell. The house is under negative pressure.

Question 34

How does supply ventilation work?

Answer 34

The air handler draws filtered outdoor air into the home, pressurizing it. Stale indoor air exits through air leaks.

Question 35

How does balanced mechanical ventilation work?

Answer 35

It supplies and exhausts ventilation air through a dedicated system. It doesn’t rely on infiltration/exfiltration. It reduces energy, safety, and moisture problems. Uses and HRV or ERV.

Question 36

What does a Heat recovery ventilator (HRV) do?

Answer 36

Transfers heat between incoming and outgoing ventilation air streams. Recommended for cold/dry climates.

Question 37

What does an Energy recovery ventilator (ERV) do?

Answer 37

Transfers heat and moisture between incoming and outgoing ventilation air streams. Recommended for hot/humid climates.

Question 38

What are some steps in a Health and safety audit?

Answer 38

Identify combustion sources, verify CO detector and smoke detectors, identify dust and VOC sources, lead and asbestos, determine adequate ventilation, etc