ARE Study Review

The following ducts sizes (inches) are given as rough equivalents to deliver the same CFM. Based on shape, which offers the least resistance to air movement and the least friction? A. 5x12, B. 6x10, C. 7x8, D. 9 dia.

Night sky radiation, water from a site, soil or earth and ambient outside air (sensible) are all sources of what?   A. source component providing heat, B . electrical resistance, C. warmth, D. coolth

Which of the following is NOT a basic type of all-air systems that would be used for larger buildings? Choose 2 A. VAV, B. Reheat system, C. Electric resistance D. Dual-duct, E. Multizone, F. Hydronic Radiant

What is typically the maximum diameter of an air duct running through a set of open-web joists? A. 1/4 joist depth B. 1/3 joist depth C. 1/2 joist depth D. 5/8 joist depth

Which of the following systems is a more expensive type of heating system? A. electric resistance B. small space heating C. wood & pellet fuel D. hydronic radiant Answer A. electric resistance heating is most expensive, using electricity as its source. Small space heating is not a central heating system, but can be efficient in limited uses. ARE 4.0 exam prep: BS

Roughly 3 tons of cooling is being estimated for a 2,700 square foot residential building. Choose 2 locations in which this estimation can be applied. A. Rhode Island B. Ontario, Canada C. Nevada D. North Carolina Answer A and B are the best answers. As a rule of thumb, 1 ton will cool 800-1000 sf in the northern US and Canada, but only 450-700 sf in the southern US. Thus, 2700 sf divided by 900 sf per ton = 3 tons. ARE 4.0 exam prep: BS

A water cooled liquid chiller (photo) performs which function in the refrigeration cycle for HVAC systems? A. thermal expansion valve, reducing pressure from the refrigerant's liquid state B. condenser cooling hot refrigerant with ambient air C. heat exchanger for liquid to cool air or equipment D. removes heat from liquid by vapor-compression or absorption refrigeration Answer D. removes heat from liquid by vapor-compression or absorption refrigeration. Industrial chillers may combine the chiller unit, condenser, pump station and expansion valve into a packaged unit. ARE 4.0 exam prep: BS

Friction loss or static head in sizing of air ducts is given in this expression of units: A. pounds per square inch B. inches of water per 100 feet C. inches of refrigerant per 100 feet D. inches of water per foot Answer B. inches of water per 100 feet ARE 4.0 exam prep: BS

An imbalance in air pressure is apparent in this illustration, indicating that _________ is inducing ________. Select two words to fill in these blanks. A. duct leakage B. negative pressure C. infiltration D. positive pressure E. increased supply fan rate Answer Duct leakage (A) induces infiltration (C), illustrating negative pressurization. Ensuring the supply fan rate is greater than sum of the return and infiltration rates will positively pressurize the building. Eliminating duct leaks will resolve the initial cause. ARE 4.0 exam prep: BS

Which of the following is NOT considered in addressing duct noise? A. Connections B. Flow volume C. Floor space D. Velocity E. Friction Answer C. Floor space only. ARE 4.0 exam prep: BS

Place the ducts in this image in order of efficiency, from most to least efficient: I. Square II. Round III. Rectangular, long horizontal IV. Rectangular, long vertical A. III, IV, I, II B. I, IV, III, II C. II, III, IV, I D. II, I, IV, III Answer D. The most efficient shape is one using the least perimeter length in relation to cross-sectional area and minimized friction loss to move a volume of air. ARE 4.0 exam prep: BS

This mechanical control functions as a mechanical substitute for an open window. By mixing outdoor air with recirculated indoor air when exterior temperatures are low, requirements for refrigeration and cooling are reduced. Select 2 terms associated with this efficiency technique: A. Displacement ventilation B. Free cooling C. Economizer cycle D. AFUE Answer An air-side (C.) economizer cycle is described, and is often referred to as a (B.) free cooling concept. ARE 4.0 exam prep: BS

Select correct fill-in: Higher duct velocities result in ( higher / lower ) duct system resistance, which results in ( decreased / increased ) fan horsepower. Answer Higher duct system resistance - or pressure drop, Increased fan horsepower ARE 4.0 exam prep: BS

What division in the Facility Services Subgroup addresses specifications for fire suppression systems, including standpipes, hoses, detection and alarms? Answer Division 21 is reserved for Fire Suppression. ARE 4.0 exam prep: CDS

How should air ducts be run when perpendicular to secondary beams? Answer They must run below the beam. ARE 4.0 exam division: Structural Systems