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Flashcards in HVAC Deck (223)
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1

stWhat is this and what does it do?

opposed-blade/ balancing. It regulates flow of air

2

What boiler component is the arrow pointing to?

Burner

3

What boiler component is the arrow pointing to?

Access door

4

What is the arrow pointing to?

Breeching connect to chimney allows hot gases to pass through to the outside of the building

5

What is the arrow pointing to?

 

Firebrick or other fire resistant material

6

What is the arrow pointing to?

Combustion Chamber

7

What are the arrows pointing to?

A. steam or hot water

B. cast iron boiler section

8

15

A small one-story building in a temperate climate has been design with its long side oriented south. If a southern view is not a concern, the best passive solar heating method would be A. direct gain space B. Trombe wall C. greenhouse D. convection loop

B. Trombe wall If view is a consideration, a direct gain space, greenhouse, pr convective loop using mass in teh flooring and wall materials would be a better choice.

16

The stored heat in a Trombe wall is circulated by what means?

convection

17

What is the primary disadvantage of a Trombe wall?

Trombe wall are most effective when oriented south and situated behind glass. however, they block potential views and block glazing that could be a window.

38

True or False: Hydronic systems can be combined with forced air systems

True

43

COP Stands for: a. Creative Office Plan b. Coefficient Of Photovoltaic’s c. Coefficient of Performance d. Commissioning is an Organized Process

c. Coefficient of Performance

45

True of False: An evaporative chiller and a cooling tower are not the same thing.

False

48

Duct sizes are given in: a. Square feet of cross sectional area b. Square yards of cross sectional area c. Square inches of cross sectional area d. Square cubits of cross sectional area

c. Square inches of cross sectional area

49

In duct sizing, the friction loss is expressed in_____ this is also known as Static Head. a. Inches of Freon per 100 feet b. Inches of water per 10 feet c. Inches of water per 100 feet d. Inches of cool-aid per 1000 feet

c. Inches of water per 100 feet

51

What system automatically adjusts heating or cooling output and distributes the air between various zones as required? a. Multi-zone system b. Dual duct system c. Automatic thermal control system d. 4 pipe system

c. Automatic thermal control system

53

A centrifugal fan is also called a: a. Circular fan b. Squirrel cage blower c. Centripetal fan

b. Squirrel cage blower

57

Gray water is NOT derived from which of the following? a. Lavatories b. Roof drains c. Effluent d. Swales

c. Effluent

61

What does a pressure relief valve do for a boiler?

Relieves excess system pressure. Usually set at 30 psi

132

Melting ice consumes A. enthalpy B. sensible heat C. dew point temperature D. latent heat

D. latent heat The addition of sensible heat is what raises the temperature, but at 32 deg F the addition of more heat no longer immediately raises the temperature more. Instead, the added heat serves to melt the ice, and the temperature doesn't rise again until the ice is melted.

158

Which HVAC system would be the most appropriate choice for a hospital? A. multizone B. high velocity dual duct C. variable air volume D. fan coil with supplementary air

A. fan coil with supplementary air A system that exhausts all return air would be the best choice. A fain coil with supplementary air would satisfy this requirement. All other systems listed return room air to the main AHU where some if it is reused.

159

Which of the following contributions to indoor air quality can be controlled by the HVAC system? (choose 4) A. outgassing B. air change effective ness C. VOC content of building materials D. carbon dioxide levels E. humidity F. mold growth

BDEF

160

1 ton of air conditioning = ____Btu/hr?

12,000

161

Energy transfer wheel

A. temper incoming air with exhaust air

B. use ground temperature for heating or cooling

C. capture the heat of flue-gases to warm cold water

D. exchange heat from solar panels to an airstream

A. temper incoming air with exhaust air

 

AN energy transfer wheel transfers heat between two airstreams (incoming air and exhaust air) using a lithium chlooride-impregnated heat exchanger. 

Option B decribes a ground source heat pump. This type of system uses the constant temperature of the ground to heat or cool a building. Option C describea boiler fuel economizer. Option D describes a standard heat exchanger

162

Which of the following energy sources would be the most economical option for heating a small reatil building in Washington state?

 

A.  electricity

B. natural gas

C. oil

D. steam

A. electricity

 

In the NW part of the USA, electrical generating facilities are plentiful and provide a relatively low cost way to heat buildings

Natural gas is popular in the Midwest, while oil is commonly used in the northeastern USA. Steam is not economical unless it is produced in a central facility for use in an urban area or is a by -product of other types. 

163

Which of the following have a significant effect on heat gain?

 

I. motors

II. sunlight

III. people

IV. flourescent lighting

V. humidity

 

A. II, III only

B. II, III, V

C. I, II, III, iV

D. I, II, III, IV, V

C. I, II, III, iV

 

Humidity does not affect heat gain. 

164

In calculating solar heat gain, what value must be known in adition tot eh area of the glass?

 

A. mean radiant temperature

B. design cooling factor

C. equivalent temperature difference

D. coefficient of heat transfer

B. design cooling factor

 

The desgin cooling factor and the area of glass must both be known to calculate solar heat gain. 

 

Equivalent temperature difference is used to calculate heat gain through the building envelope, such as walls and roofs. 

165

Select the INCORRECT statement.

 

A. relative humidity is the best measure of thermal comfort

B. People feel more comfortable in the winter if the MRT is high

C. There are differences in comfort level among different cultural groups

D. The range of comfortable dry-bulb temperatures is depndent on air movement

A. relative humidity is the best measure of thermal comfort

 

Although relative humidity affects the way a person feels in a space, it is not the primary measure of thermal comfort. Effective temperature (ET) is a better indicator of comfort because because it takes all the variables into account. For example, even at a high humidity of 75%, if the temperature is cool enough or there is enough of a breeze, most people will feel comfortable. 

166

A developer in a midsize Arizona city is planning to build a small shopping mall for resale. The one story mass will consist of 40,000 sq ft of rentable area surrounding a small enclosed courtyard. Existing utilities adjacent to the sire include water, sanitary sewer, storm sewer, natural gas, and electricity. Which three of the following factors would be the most important in the selection of an HVAC system for this project?

I. flexibility

II. climatic zone

III. economics

IV. the tenant's preference

V. building scale

 

A. I, II, V

B. I, III, IV

C. II, III, IV

D. II, III, IV

D. II, III, IV

 

The climatic zone, scale of the building, and cost and efficiency of the HVAC system would drive the specification. The shopping mall would be planned for relatively fixed sizes of rental spaces, so flexibility would not be one of the most important considerations. Because the tenant mix would probably not be completely known at the time of design, the tenant's preference could not be solicited even if it were appropriate.