Abbreviations
AHU	Air Handling Unit
CM	Compressor
CN	Condenser
COP	Coefficient of Performance
EV	Evaporator
FLT	First Law of Thermodynamics
FN	Fan
HP	Heat Pump
HRE	Heat Recovery Exchanger
HVAC	Heating, Ventilation and Air Conditioning
RT	Reference Temperature
SLT	Second Law of Thermodynamics
TV	Throttle Valve
ZLT	Zero Law of Thermodynamics
Variables
A	surface area (m2)
cp	specific heat capacity (kJ/kg·K)
e	specific exergy (kJ/kg)
$\dot{E}$	exergy flow rate (kW)
h	enthalpy (kJ/kg)
$\dot{K}$	coenthalpy rate (kW)
k	specific coenthalpy (kJ/kg)
l	specific destroyed exergy (kJ/kg)
$\dot{L}$	destroyed exergy (kW)
$\dot{M}$	mass flow rate (kg/s)
$\dot{Q}$	heat transfer flow rate (kW)
Ri	inlet to room (K)
Ro	outlet from room (K)
$\dot{s}$	specific entropy (kJ/kg·K)
$\dot{S}$	entropy (kW/K)
T	temperature (K)
U	overall heat transfer coefficient (W/m·K)
Δ	difference (–)
${\epsilon }_T$	effectiveness of heat recovery exchanger (–)
${\eta }_C$	Carnot factor (–)
ηex	exergy efficiency (–)
Subscripts
a	air
AHU	air handling unit
c	cooler fluid
e	state of reference environment
CNizot	isotherm in the condenser
EVizot	isotherm in the evaporator
f	Freon / refrigerant
h	hotter fluid
i	state of fluid
irr	produced / irreversible
ln m	logarithmic mean
R	room
V	ventilation
w	warm exhausted air after HRE
1	in
2	out
Superscripts
h	hotter fluid
q	heat transfer
+	to the system
–	out of the system