Focused On The Engineered Environment

61 Milford Dr.     Hudson, OH     44236

Cleveland: (330) 463-0100     Akron: (330) 342-9400     Fax: (330) 463-0101

www.jacco.com

The Aaon Digital Precise Air Control (D-PAC) unit is the 2008 Most Valuable Product according to Consulting-Specifying Engineer Magazine.  The Product of the Year awards were established by the magazine to present  readers with the top new products in the MEP industry.  The winner was chosen by the readers through a voting process established online. 

The D-PAC unit was designed with the intention of optimizing technology and control logic to maintain space temperature and humidity in the most energy efficient manner possible.  The result is the ability to control temperature within ±1°F and humidity within ±5% RH at all ambient conditions and with         efficiencies that rival a chilled water system. 

 

OA & RA enters the unit through a 3 section economizer with independent dampers for     

OA, RA and RA Bypass.  A mixture of OA  

           and RA will always go through the cooling coil.

 

The RA Bypass damper modulates to provide reheat to the MA passing through the cooling coil.  Up to 50% of the RA can be bypassed and used for reheat to control light humidity loads.

 

The DX coil dehumidifies the MA to maintain latent cooling and dehumidification loads.

 

The Modulating Hot Gas Reheat Coil raises the MAT in order to satisfy the sensible cooling load when the RA Bypass air is not enough.  The  reheat coil is used to control high humidity loads.

 

The Digital Scroll Compressor modulates from 10-100% capacity for tighter temperature control, greater dehumidification and lower operational costs.  The compressor capacity modulates according to the cooling and dehumidification loads.

 

The Digital Precise Controller controls all components in the D-PAC unit including fan, outside air, return air and return air bypass actuators, modulating hot gas reheat, modulating compressor, heating and optional energy recovery wheel to insure proper operation, tight temperature and humidity control, and energy efficiency.

 

Assume the ambient conditions of 95°F DB and 75°F WB with 2,800 CFM of supply air, 700 CFM of which is    outside air.  The unit is attempting to control to 75°F space temperature and if the unit includes humidity   control options 45% space relative humidity.  The space part load conditions are 10 MBH sensible load and       10 MBH latent load for a sensible heat ratio of 0.5.    Supply fan motor heat is neglected.

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