At the boiler...

Absorbed by the engine...

At a hot reservoir...

Heat added to an engine...

Gained by the gas of a heat engine...

Behind the refrigerator...

Outside the refrigerator...

Dissipated by a refrigerator...

Released by the refrigerant...

Engine takes in heat...

Given off to the air around a refrigerator...

At a cold reservoir...

Lost as exhaust...

Inside the refrigerator...

After the piston of a heat engine...

Absorbed by the refrigerant...

Released by the gas of a heat engine...

Lost by the air inside the refrigerator...

When an object is cooled by a refrigerator...