ASHRAE 90.1 (2004): HVAC tab

Contains controls used to view prescriptive option compliance results for the HVAC portion of the ASHRAE 90.1 (2004) requirements. HVAC systems are the equipment, distribution systems, and terminals that provide, either collectively or individually, the processes of heating, ventilating, or air conditioning to the project building.

HVAC requirements are specified in section 6 (and 11) of the ASHRAE 90.1 (2004) standard, and include general provisions, the Simplified Approach and Mandatory Provisions compliance path options. The Mandatory Provisions option contains two compliance options as well, the Prescriptive Path and the Energy Cost Budget Method (section 11 of the standard).

Tip: You can open the Results Viewer utility to step through the calculations for displayed results by selecting the result value and clicking for more information (as prompted).

Setting	Description
HVAC	Displays prescriptive results for the HVAC systems in the project building. The results reported here provide information about each piece of HVAC equipment which is then used to determine if the HVAC systems comply with the minimum power efficiencies required by the standard. Equipment Name – Lists the name of each piece of HVAC equipment in the building. Equipment Type – Lists the type of equipment each piece of HVAC equipment is. Equipment types displayed here include air conditioners, condensing units, and heat pumps. Size Category – Lists the size categories which determine the compliance eligibility of each piece of HVAC equipment in the building. The categories are taken from the minimum efficiency requirements for listed equipment tables that are provided in the standard. Sub-Category – Lists the equipment sub-category or Rating Condition. Rating conditions are used to adjust minimum efficiency requirements because simulations can not completely simulate every aspect of HVAC systems. Units of Efficiency – Lists the units used to display listed efficiencies for each piece of HVAC equipment in the building. Minimum Efficiency – Lists prescriptive results for the factors that determine the minimum efficiencies required for each piece of HVAC equipment in the building. To comply, the HVAC equipment must meet the minimum efficiency requirements for listed HVAC equipment which is determined at specific rating conditions and tested in accordance with specified testing procedures. Rated – Lists the rated efficiencies (determined by prescribed tests by the manufacturer) for each piece of HVAC equipment in the building. Required – Lists the required minimum efficiencies for each piece of HVAC equipment in the building calculated using the equipment information such as type, size category and sub-category. Pass/Fail – Displays an overall result of the HVAC equipment compliance with the HVAC requirements prescribed by the standard.
Centrifugal Chillers	Displays prescriptive results for the centrifugal chillers in the project building. The results reported here provide information about each centrifugal chiller which is then used to determine if the chilled water systems comply with the minimum power efficiencies required by the standard. There are special requirements for unlisted centrifugal chillers. That is, centrifugal chillers that are not designed for the standard ARI (Air-Conditioning and Refrigeration Institute) rating conditions. For those systems, chiller efficiency is determined as a function of the leaving chilled water temperature, entering condenser water temperature, and condenser water flow rate per unit capacity. Equipment Name – Lists the name of each centrifugal chiller in the building. Leaving CHW Temperature – Lists the leaving chilled water temperature for each chiller in the building. Entering CW Temperature – Lists the entering condenser water temperature for each chiller in the building. Condenser Flow Rate – Lists the condenser flow rates for each chiller in the building. Size Category – Lists the size categories which determine the compliance eligibility of each centrifugal chiller in the building. The categories are taken from the minimum efficiency requirements for listed centrifugal chiller tables that are provided in the standard. Minimum Efficiency – Lists prescriptive results for the factors that determine the minimum efficiencies required for each centrifugal chiller in the building. To comply, the chiller must meet the minimum efficiency requirements for centrifugal chillers which is determined at specific rating conditions or by the CHW temperatures function. Rated – Lists the rated efficiencies for each centrifugal chiller in the building. Required – Lists the required minimum efficiencies for each centrifugal chiller in the building calculated using the equipment information such as entering and leaving chilled water temperatures, flow rates, and size category. Pass/Fail – Displays an overall result of the centrifugal chillers compliance with the chiller requirements prescribed by the standard.
Fans	Displays prescriptive results for the fans in the project building. The results reported here provide information about each fan which is then used to determine the fan power limitation for the building. Fans are typically the largest energy consuming components of HVAC systems. The fan power limitation regulates the amount of power used for fans, improving efficiency, and is defined as the ratio of the fan system power to the supply fan airflow rate at design conditions. To comply, the total fan power used by the fans in the building must not exceed the limits prescribed in the standard. Supply Fan – Displays prescriptive results for the supply fans in the project building. Fan ID – Lists the name of each supply fan in the building. Supply Volume – Lists the supply air flow rate for each supply fan in the building. Motor – Lists the nameplate motor power rating of each supply fan in the building. Return Fan – Displays prescriptive results for the return fans in the project building. Fan ID – Lists the name of each return fan in the building. Motor – Lists the nameplate motor power rating of each return fan in the building. Exhaust Fan – Displays prescriptive results for the return fans in the project building. Fan ID – Lists the name of each exhaust fan in the building. Motor – Lists the nameplate motor power rating of each exhaust fan in the building. Series-Style Fan Powered Box – Displays prescriptive results for the series—style fan powered boxes in the project building. Fan ID – Lists the name of each series—style fan powered boxes in the building. Motor – Lists the nameplate motor power rating of each series—style fan powered boxes in the building. Total System Motor – Lists the total sum of all the power the building fans consume. This is used to calculate the fan power allowance and adjusted power allowance for the building.