Exam (elaborations)
BOMA HVAC MASTER QBANK – Questions & Solutions
- Course
- Institution
BOMA HVAC MASTER QBANK – Questions & Solutions
[Show more]
Content preview
BOMA HVAC MASTER QBANK – Questions & SolutionsThe man whose work is considered the real beginning of the science of air-
conditioning _____. Correct Ans - Willis Carrier
Psychrometry refers to the relationship between _____ and _____. Correct Ans - Humidity; air
The amount of moisture in the air compared to how much it can hold is _____. Correct Ans - Relative humidity
The human bodies well-being depends upon the _____. Correct Ans - Body's metabolism
The device used to determine the moisture content of air is the _____ Correct Ans - psychrometer
Of the fuels listed the one that is the most efficient is _____. Correct Ans - Gas
The effective temperature takes into consideration the effect of _____ and _____. Correct Ans - Humidity; temperature
Air conditioning is the control of the _____, _____, _____ and _____. Correct Ans - Temperature, humidity, purity and distribution of air.
The element that makes up the greatest percentage by volume of air is _____. Correct Ans - Nitrogen
Steam gives off a great amount of heat because of its _____. Correct Ans - Specific heat
The velocity of air moving thru a fan system is expressed in _____. Correct Ans - Feet per minute
What volume of air will move thru a duct 24x18 at velocity of 450 feet per minute? Correct Ans - 1350 cfm The following types of fans are classified as centrifugal fans. Correct Ans - Forward curved, radial and backward curved
Select the statement that does not apply to backward inclined (Non overloading) fans. Correct Ans - Has an overloading (BHP) horse power curve.
The quantity of air moving thru a fan system is expressed in _____. Correct Ans - Cubic feet per minute
The instrument used to measure air pressure in duct is the _____. Correct Ans - Monometer
Air flow thru a duct has the highest _____. Correct Ans - Velocity near the center of the duct.
Select the statement which does not apply to the fan laws. Correct Ans - Static pressure in a duct increases as the velocity decreases
Variable air volume system feature is _____. Correct Ans - Varies the volume of air with space temperature conditions
Double duct systems are _____. Correct Ans - Used in multi-room buildings having variable heat loads
The purpose of a primary control is to _____. Correct Ans - Start or stop the system
A pressure stat responds to _____. Correct Ans - System pressure
The oil safety switch is operated by _____. Oil pressure Correct Ans - A low limit control _____. Correct Ans - Provides for safe cutoff of the system.
A high limit control _____. Correct Ans - Provides for safe cutoff of the system
Limit controls _____. Correct Ans - Are wired into the circuit in series A diluting switch is used to _____. Correct Ans - Change proportional action to two position control.
A proportional control: Correct Ans - Where a movement from the set point produces a proportional movement of the actuator
A three way diverting valve: Correct Ans - has two outlets and one common inlet
Heat will continue to flow between two bodies until they have the same amount of _____. Correct Ans - Sensible heat
Heat which causes a change of state is _____. Correct Ans - Latent heat
The refrigeration effect of a refrigerant is improved by _____. Correct Ans -
Subcooling the liquid.
In the refrigeration cycle, the medium that picks up the heat is the _____. Correct Ans - refrigerant.
A heat exchanger _____. Correct Ans - Sub cools the liquid refrigerant
Calculations involving heat load of people takes into consideration heat due to
_____ and _____. Correct Ans - Latent heat; sensible heat
The flow control device used to maintain system temperature is the _____. Correct Ans - Evaporator pressure valve
Enthalpy refers to the _____. Correct Ans - Heat content of the refrigerant
The metering device is designed to _____. Correct Ans - Control flow of refrigerant
The evaporator pressure regulator (EPR). Correct Ans - Limits evaporator pressure Assume a centrifugal unit with R11 is operating at 8.8 PSIG condensing pressure and 86 degrees condensing temperature, what is the partial pressure
due to air? Correct Ans - 5.6 (see chart) (insert picture)
Utilizing the values in the above problem, what is the partial pressure due to the refrigerant? Correct Ans - 3.2 (see chart)(insert picture)
The most efficient method of capacity control is by the use of _____. Correct
Ans - Speed control
The pump out unit: Correct Ans - is used to transfer the refrigerant to an external receiver.
The movement of the pre-rotation vanes is controlled by the _____. Correct Ans - Chill water temperature control.
The function of the economizer is to _____. Correct Ans - Increase the refrigeration effect.
Economizers: Correct Ans - for the same power input, capacity is increased
The least likely cause at high suction pressure would be _____. Correct Ans - Not enough system load
A psychometric chart is a graphic representation of _____? Correct Ans - Thermodynamic properties
Enthalpy refers to the _____? Correct Ans - Measure of energy content of a
substance
What is an excellent heat carrier because it _____? Correct Ans - Has high specific heat
The element that makes up the most percentage of air is _____? Correct Ans
- Nitrogen
Air flows through a duct has the most _____? Correct Ans - Velocity near the center of the duct
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller LeCrae. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $26.99. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
62890 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now