Final answer:
The economizer is commonly located between the condenser and evaporator in HVAC systems to pre-cool the refrigerant and save energy.
Step-by-step explanation:
The economizer is typically located in air conditioning and refrigeration systems to improve efficiency. It is not explicitly mentioned in the provided information, but based on standard HVAC system designs, the economizer is usually found between the condenser and evaporator. It functions to pre-cool the refrigerant before it enters the evaporator, making use of the cooler outdoor air and thus saving on the energy that the compressor would need to use.