Next, select the equipment capacity curve created earlier by using the drop-down menu for the Secondary Unloading Curves in the Capacity field. In the Unloading Curves section, select the DOE Curve type.Į. Click the Copy button on the Main tab and rename the equipment.ĭ. Select the desired 90.1 heat pump equipment.Ĭ. Access the Cooling Equipment Library and select the Air Cooled Unitary option in the Cooling category field.ī. The equipment capacity curve will need to be associated with the correct 90.1 heat pump equipment that you are using for your project.Ī. Step 2: Assign the Equipment Capacity Curve to the appropriate cooling equipment. So, for OADB temperatures below 17F, the heat pump heating capacity is 0 and above 40F, the capacity is 100%. Next, in the Curve Fit Boundary Values section of the window, set the YCond Minimum to 17F and the YCond Maximum to 40F. To obtain 100% equipment capacity at OADB = 40 and vary it linearly to 0% at OADB =17F (i.e., Y1 = 0, X1=17 and Y2=1, X2=40): This means the capacity multiplier equation reduces to Y = C1 + C4*Oadb To make the equation linear, set C5=0 as well. All equipment capacity curves are biquadratic in form only as indicated below: The equipment capacity curve is created in the Curves library. This is most likely to happen at morning startup when the unit sees maximum heating loads as the rooms shift from setback to room design heating dry bulb. With this capacity curve, the backup heating source will supplement the heat pump compressor output to meet the hourly load (up to the heat pump design heating capacity) by compensating for the decrease in heat pump heating output as the OADB temperature decreases. It is assumed that 100% capacity is available at OADB = 40F and then the heat pump output capacity decreases linearly to 0% at OADB = 17F. The decrease in heat pump heating mode capacity will result in the additional heating load being picked up by the backup heating equipment.ĪSHRAE Standard 90.1 does not provide a heating capacity curve for air-to-air heat pumps. The equipment capacity curve will reduce the capacity of the associated equipment as the outdoor air dry bulb temperature decreases from 40F to 17F. However, most of the equipment in the TRACE library assumes a constant capacity and this normally yields valid results. In reality, the output capacity of most equipment changes based on operating conditions. It is the third curve used in conjunction with the power consumed and ambient modification curves. The equipment capacity curve can be seen in the Cooling Equipment library. Input an equipment capacity curve as illustrated below: Step 1: Create an Equipment Capacity Curve
![2007 ashrae 90.1 2007 ashrae 90.1](https://www.mdpi.com/sustainability/sustainability-13-10050/article_deploy/html/images/sustainability-13-10050-g006.png)
Therfore, the curve doesn't need to be manually generated and applied to equipment.
2007 ASHRAE 90.1 SOFTWARE DOWNLOAD
This curve is part of the 90.1 heat pump libraries that can be downloaded from the CDS HVAC Design Software Download Center at.