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Flashcards in Health and Safety Deck (38)
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1
Q

What are hydrocarbon combustion fuels?

A

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.

2
Q

What are the byproducts of combustion?

A

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

3
Q

What is spillage?

A

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

4
Q

What is backdrafting?

A

Continuous spillage at a flue

5
Q

What causes carbon monoxide release?

A

Incomplete combustion

6
Q

Describe carbon monoxide.

A

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

7
Q

What are the most effective solutions to handle dust?

A

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

8
Q

What are some common VOC sources?

A

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

9
Q

Where does radon come from?

A

Rocky soil

10
Q

What is Asbestos?

A

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

11
Q

What’s the number one enemy of buildings?

A

Water

12
Q

What is capillary seepage?

A

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

13
Q

Water vapor moves in what two ways?

A

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

14
Q

What are some sources of liquid water in buildings?

A

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

15
Q

When do ice dams occur?

A

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.

16
Q

Water vapor always flows from…

A

high pressure to low pressure (wet to dry)

17
Q

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

A

Vapor pressure

18
Q

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

A

True

19
Q

What is relative humidity?

A

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.

20
Q

As air cools, its relative humidity _____.

A

increases

21
Q

Condensation problems increase with:

A

Increase in absolute humidity

Decrease in temperature

22
Q

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

A

8 ACH (Air changes per hour)

23
Q

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

A

Attics and crawl spaces

24
Q

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

A

150

25
Q

Should crawlspaces be vented?

A

No, they should be closed and conditioned.

26
Q

How does and air conditioner work?

A

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

27
Q

How does a dehumidifier work?

A

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

28
Q

What are some effective interior air barriers?

A

Drywall, concrete, plywood, and Tyvek

29
Q

What are some effective exterior air barriers?

A

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

30
Q

What’s a vapor barrier?

A

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

31
Q

What are the two primary strategies for ventilation?

A

Ventilation through air leakage and mechanical systems

32
Q

What are 3 types of mechanical whole-house ventilation?

A

Exhaust, supply, balanced

33
Q

How does a central exhaust ventilator work?

A

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.

34
Q

How does supply ventilation work?

A

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

35
Q

How does balanced mechanical ventilation work?

A

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.

36
Q

What does a Heat recovery ventilator (HRV) do?

A

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

37
Q

What does an Energy recovery ventilator (ERV) do?

A

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

38
Q

What are some steps in a Health and safety audit?

A

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