HVAC Systems — Texas ACR A Practice Questions

22 questions · 9% of the Texas ACR A exam

Worked questions

1. Only the cooling capacity of a walk-in refrigeration system, 7.5 tons, is supplied. Its electrical nameplate and installation instructions are unavailable. What disconnect ampere rating can be determined from cooling capacity alone?

AExactly 50 A
BExactly 60 A
No disconnect ampere rating can be determined from cooling tons alone.
DExactly 80 A

Where to look it up

Explicit exercise assumptions; not a universal code requirement.

Why C is correct

Cooling tons measure thermal capacity, not electric current. Disconnect selection requires the relevant electrical equipment data and applicable installation rules. A 125% multiplier applied to tons still gives tons and cannot establish a 70 A disconnect.

2. A refrigeration system is supplied at 480 V, three phase. No overcurrent-protection rating, conductor material or other circuit data are supplied. Can its equipment grounding conductor size be selected from voltage and phase alone?

AYes, always 6 AWG
No; additional circuit and applicable sizing-rule information is required.
CYes, always 10 AWG
DYes, always 12 AWG

Where to look it up

Explicit exercise assumptions; not a universal code requirement.

Why B is correct

Voltage and phase alone do not provide the inputs needed to select an equipment grounding conductor. Do not infer 8 AWG from 480 V or confuse equipment grounding with grounding-electrode conductor sizing.

3. Which approach should guide an office HVAC filter maintenance schedule?

Follow the filter and system instructions, inspect condition and pressure drop, and service as required.
BAlways wait six months regardless of condition.
CAlways wait twelve months regardless of condition.
DReplace only when the fan stops.

Where to look it up

https://www.cdc.gov/infection-control/hcp/environmental-control/air.html

Why A is correct

Filter loading varies with use and conditions. Follow manufacturer instructions and maintenance criteria, including inspections and specified pressure limits. A universal calendar interval alone does not establish that a filter remains serviceable.

4. For a stated sensible-heat exercise, use heat gain = 1.08 × airflow × temperature rise. At 1,000 cfm and 10,800 Btu/h of duct heat gain, what is the temperature rise?

A1°F
B20°F
10°F
D100°F

Where to look it up

Explicit exercise assumptions; not a universal code requirement.

Why C is correct

Temperature rise = 10,800 / (1.08 × 1,000) = 10°F. The supplied approximation is for this exercise, not a universal limit for a particular insulation thickness or duct length.

5. A dust-capture hood is designed for 600 cfm through a 4 ft² opening. Assuming uniform flow, what is its average face velocity?

A2,400 ft/min
150 ft/min
C25 ft/min
D600 ft/min

Where to look it up

Explicit exercise assumptions; not a universal code requirement.

Why B is correct

Average velocity = volumetric flow / area = 600 / 4 = 150 ft/min. This is a face-velocity calculation, not proof of adequate capture or a universal industrial ventilation minimum.

6. A retail refrigerated display holds time/temperature control for safety food under 2022 FDA Food Code 3-501.16(A)(2), with no exception applying. Which maximum food temperature applies?

A32°F
41°F
C45°F
D50°F

Where to look it up

https://www.fda.gov/media/164194/download

Why B is correct

The food must be held at 41°F or less under the specified provision. Cabinet air settings are chosen to maintain the required food temperature under actual loading and operating conditions; this is not a universal display-case thermostat setting.

16 more in the bank

Answers and explanations for these are in the app.

A school is renovating its classrooms and wants to ensure adequate ventilation. According to the Texas Administrative Code Chapter 75, what is the minimum outdoor air ventilation rate required for classrooms?
A Texas Environmental Air Class A contractor is installing a new kitchen exhaust system in a residential building. The system is designed to exhaust 1,200 cfm of air. What is the minimum required size of the exhaust fan, in square inches, according to the 2024 IMC?
An office building is being designed with a VAV system. The total cooling load for the building is 1,000 tons. According to the ACCA Manual J, what is the minimum number of cooling coils required if the system has a 1.5 cooling coil efficiency?
In a commercial building, the HVAC system is designed to provide 100% outdoor air ventilation. The system has a total of 10 supply diffusers. According to the 2024 IFGC, what is the minimum number of exhaust air outlets required if the total supply air is 10,000 cfm?
In a hospital, the HVAC system is designed to provide a specific airflow pattern in operating rooms. According to the 2024 IMC, what is the minimum velocity required for the supply air in these rooms?
In an industrial facility, what is the recommended temperature rise across the cooling coils to prevent freezing conditions as per the 2024 UMC, Section 1806.3?
What is the maximum allowable air flow noise level for air conditioning systems as per ACCA Manual D, Section 8.4?
What is the maximum allowable velocity for supply air ducts in an industrial facility according to the 2024 IFGC Section 601.3?
What is the minimum exhaust air flow rate required for a commercial kitchen exhaust system according to the 2024 IMC Section 403.3.1?
What is the minimum heating system efficiency required for a school building according to the 2024 IMC Section 901.2.1?
What is the minimum outdoor air supply required per person in a residential bedroom as per the 2024 IMC, Section 403.4?
What is the minimum outdoor air ventilation rate required for a bedroom in a residential building according to the 2024 IMC Section 403.3.1?
What is the recommended humidity level for a museum's HVAC system to prevent damage to artifacts?
What is the standard pressure for the high-pressure side of a refrigeration system as per Modern Refrigeration and Air Conditioning 22nd ed., Chapter 5?
Which type of air distribution system is typically used in a commercial kitchen to handle high heat loads?
Which type of air filter is most commonly used for maintaining air quality in commercial HVAC systems as per the 2024 IFGC, Section 601.4?

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HVAC Systems — Texas ACR A Practice Questions

Worked questions

1. Only the cooling capacity of a walk-in refrigeration system, 7.5 tons, is supplied. Its electrical nameplate and installation instructions are unavailable. What disconnect ampere rating can be determined from cooling capacity alone?

2. A refrigeration system is supplied at 480 V, three phase. No overcurrent-protection rating, conductor material or other circuit data are supplied. Can its equipment grounding conductor size be selected from voltage and phase alone?

3. Which approach should guide an office HVAC filter maintenance schedule?

4. For a stated sensible-heat exercise, use heat gain = 1.08 × airflow × temperature rise. At 1,000 cfm and 10,800 Btu/h of duct heat gain, what is the temperature rise?

5. A dust-capture hood is designed for 600 cfm through a 4 ft² opening. Assuming uniform flow, what is its average face velocity?

6. A retail refrigerated display holds time/temperature control for safety food under 2022 FDA Food Code 3-501.16(A)(2), with no exception applying. Which maximum food temperature applies?

16 more in the bank

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