HVAC Residential vs Commercial HVAC

Question 1

What is the typical cooling capacity range for residential central air conditioning systems?

Accepted Answer

1.5 to 5 tons (18,000-60,000 BTU/hr)

Answer

1/2 to 1 ton (6,000-12,000 BTU/hr)

Answer

5 to 20 tons (60,000-240,000 BTU/hr)

Answer

20 to 100 tons

Question 2

What is the primary difference between a residential split system and a commercial rooftop unit (RTU)?

Accepted Answer

RTUs are self-contained (all components in one unit); split systems have separate indoor and outdoor units

Answer

Split systems are more energy efficient than RTUs

Answer

Split systems use R-22; RTUs use R-410A

Answer

RTUs only provide cooling; split systems provide both heating and cooling

Question 3

What type of control system is most common in residential HVAC versus commercial HVAC?

Accepted Answer

Residential: Simple thermostats; Commercial: Building Automation Systems (BAS) with DDC controls

Answer

Residential: BAS with DDC controllers; Commercial: simple thermostats

Answer

Both use simple thermostats equally

Answer

Both use BAS systems regardless of building size

Question 4

What is 'zoning' in HVAC systems and how does it differ between residential and commercial applications?

Accepted Answer

Residential zoning uses dampers and multiple thermostats in one system; commercial uses separate AHUs or VAV systems serving multiple zones

Answer

Zoning refers to geographic service areas for HVAC contractors

Answer

Commercial zoning uses zone thermostats; residential uses VAV boxes

Answer

Zoning is only used in commercial buildings

Question 5

What refrigerant is required in new residential split systems sold in the US starting January 1, 2025?

Accepted Answer

R-32 or R-454B (or other low-GWP alternatives)

Answer

R-22

Answer

R-410A

Answer

R-134a

Question 6

What is a key advantage of commercial chilled water systems over direct expansion (DX) systems for large buildings?

Accepted Answer

Chilled water systems use less refrigerant overall, reducing leak risk and regulatory burden

Answer

DX systems are more efficient in buildings over 100,000 sq ft

Answer

Chilled water systems require more refrigerant per ton of cooling

Answer

DX systems are better for buildings with variable loads

Question 7

What distinguishes 'light commercial' from 'heavy commercial' HVAC in terms of cooling capacity?

Accepted Answer

Light commercial: 5-20 tons; Heavy commercial: 20+ tons

Answer

Light commercial: up to 5 tons; Heavy commercial: 5-20 tons

Answer

Light commercial: up to 20 tons; Heavy commercial: 20-100 tons

Answer

Light commercial: up to 100 tons; Heavy commercial: 100+ tons

Question 8

What is a 'package unit' (packaged rooftop unit) and what are its advantages for commercial applications?

Accepted Answer

All HVAC components in one outdoor unit on the roof — simplifies installation, saves indoor space, and concentrates equipment on the roof

Answer

A unit packaged with multiple refrigerant circuits for redundancy

Answer

A unit that packages both the cooling and heat pump in one cabinet

Answer

A modular unit that can be expanded by adding sections

Question 9

What is the role of a 'cooling tower' in a commercial HVAC system?

Accepted Answer

It rejects heat from chiller condenser water to the atmosphere through evaporative cooling

Answer

It is a large air handler unit mounted on the roof

Answer

It stores chilled water for peak demand periods

Answer

It cools outdoor air before it enters the building

Question 10

What is the SEER2 rating system and how does it differ from the original SEER?

Accepted Answer

SEER2 uses updated test conditions with higher static pressure (0.5 in. wc) to better reflect real-world installation; SEER used 0.1 in. wc

Answer

SEER2 measures only cooling efficiency; original SEER measured both cooling and heating

Answer

SEER2 is measured in kW/ton; original SEER uses BTU/watt

Answer

SEER2 only applies to commercial equipment; SEER applies to residential