An option that only AAON equipment can provide in all sizes of equipment from 2-230 ton, packaged or split systems, Single Zone Variable-Air-Volume is required in two of the most prominent national energy standards, ANSI/ASHRAE/IES Standard 90.1-2010 and ANSI/ASHRAE/IES Standard 189.1-2009.

Standard 90.1-2010
Purpose: The purpose of this standard is to provide minimum requirements for the energy-efficient design of buildings except low-rise residential buildings.

ANSI/ASHRAE/IES Standard 90.1-2010. Section 6.4.3.10 Single Zone Variable-Air-Volume Controls.
HVAC systems shall have variable airflow controls as follows:

Air handling and fan-coil units with chilled-water cooling coils and supply fans with motors greater than or equal to 5 hp shall have their supply fans controlled by two-speed motors or variable-speed drives. At cooling demands less than or equal to 50%, the supply fan controls shall be able to reduce the airflow to no greater than the larger of the following:

1.       One half of the full fans speed, or
2.       The volume of outdoor air required to meet the ventilation requirements of Standard 62.1.

Effective January 1, 2012, all air-conditioning equipment and air-handling units with direct expansion cooling and a cooling capacity at AHRI conditions greater than or equal to 110,000 Btu/h that serve single zones shall have their supply fans controlled by two-speed motors or variable-speed drives. At cooling demands less than or equal to 50%, the supply fan controls shall be able to reduce the airflow to no greater than the larger of the following:

1.       Two-thirds of the full fan speed, or
2.       The volume of outdoor air required to meet the ventilation requirements of Standard 62.1

Standard 189.1-2009
Purpose: The purpose of this standard is to provide minimum requirements for the siting, design, construction, and plan for operation of high performance, green buildings to:

a.       balance environmental responsibility, resource efficiency, occupant comfort and well being, and community sensitivity, and
b.      support the goal of development that meets the needs of the present without compromising the ability of future generations to meet their own needs.

ANSI/ASHRAE/IES Standard 189.1-2009. Section 7.4.3.7 Controls.
The following requirements shall apply:
DX systems with a capacity greater than 65,000 Btu/h (19 kW) shall have a minimum of two stages of cooling capacity.

Air handling and fan-coil units with chilled-water cooling coils and supply fans with motors greater than or equal to 5 hp shall have their supply fans controlled by two-speed motors or variable-speed drives. At cooling demands less than or equal to 50%, the supply fan controls shall be able to reduce the airflow to no greater than the larger of the following:
1.       One half of the full fans speed, or
2.       The volume of outdoor air required to meet the ventilation requirements of ANSI/AHSRAE Standard 62.1.
All air-conditioning equipment and air-handling units with direct expansion cooling and a cooling capacity at AHRI conditions greater than or equal to 110,000 Btu/h (32.2 kW) that serve single zones shall have their supply fans controlled by two-speed motors or variable speed drives. At cooling demands less than or equal to 50%, the supply fan controls shall be able to reduce the airflow to no greater than the larger of the following:
1.       Two-thirds of the full fan speed, or
2.       The volume of outdoor air required to meet the ventilation requirements of ANSI/ASHRAE Standard 62.1.

All DX and chilled-water VAV units shall be equipped with variable-speed fans that result in less than 30% power at 50% flow.
Exception: When air ventilation rates or air exchange rates required constant volume fan operation.

All engineers and owners need to know that AAON is ready to meet the energy standards of tomorrow, today!

Single Zone VAV is available from AAON with:

  • Small rooftop units with efficiencies up to 19 SEER
  • Large rooftop units with efficiencies up to 14 EER
  • Small split systems with efficiencies up to 17 SEER
  • Large split systems with efficiencies up to 14 EER
  • Geothermal / WSHP units with efficiencies up to 19 EER
  • Air-source heat pumps up to 13 EER
  • Self-contained units up to 16 EER

Havtech can help you use the innovation of AAON to bring value, and savings, to your engineers and owners today! Contact your Havtech representative to learn more >

Download AAon’s SingleZoneVAV_101014 brochure >