Problem 4.10 - A Warehouse Chiller and Office Heater

We wish to do a preliminary thermodynamic evaluation of the following proposed heat pump system designed for chilling a large warehouse to around 4°C while heating the office space to 20°C.. The basic idea for this system was inspired by an article in the website on Sobey's refrigerated warehouse in eastern Canada which was honored with the ASHRAE 2010 Technology Award for having built a similar system using ammonia as the refrigerant.

Notice that our proposed system using refrigerant R134a includes an internal heat exchanger to subcool the refrigerant at the outlet of the office space heater while superheating the refrigerant at the outlet of the evaporator. This is intended to serve the dual purpose of increasing both the heating and chilling capacity of the system.
Using the conditions shown on the diagram