Miklós Kassai, László Kajtár

Air-conditioning


Nomenclature

a
absorption factor (-)
A
surface (W)
ACH
summer air change rate (1/h)
c
specific heat capacity (J/kg K)
CLTD
Cooling Load Temperature Difference (K)
e
shielding coefficient (-)
GLF
Glass Load Factor (W/m2)
h
enthalpy (kJ/kg K)
H
heat loss (W)
I
orientation factor (-)
k
air quality (ppm) / overall heat transfer coefficient (W/m2K) concentration of air pollutant (mg/m3)
intensity of contamination source (mg/h)
m
mass of air/water (kg)
m ˙
mass flow of air/water (kg/s)
n
air exchange rate (1/h) / rotation speed (1/min)
P
pressure (Pa)
Q ˙
heat flow (W)
r0
heat of phase change (kJ/kg K)
R
specific gas constants characteristic (Nm/kg K)
t
temperature (t)
V ˙
air volume flow (m3/h)
w
humidifying degree [-]
x
humidity ratio (g/kg)
Greek letters
α
heat transfer coefficient (W/m2K)
ε
effectiveness (-) / height coefficient factor (-)
ϕ
relative humidity (%)
η
effectiveness (-)
ρ
air density (kg/m3)
τ
time (sec, hour)
Subscripts
a
ambient
dry
dry air
e
exhaust
i
input/indoor
l
length / line
L
latent
o
output
S
sensible
s
supply
st
steam
t
saturated
T
total
v
water vapour
wet
wet air
ws
water stream


Kiadó: Akadémiai Kiadó

Online megjelenés éve: 2019

ISBN: 978 963 454 374 9

Nowadays, the explosion of air-conditioning systems is a global phenomenon. With their operation, pleasant thermal comort feeling can be provided for the occupants. Statistical data show that the active cooling of residental and public buildings is increasingly used also in developing countries. In these buildings, the proportion of ventilation in total energy consumption is significantly increased. There is a similar problem in the operation of buildings with post-thermal insulation. In this case, the energy demand of the ventilation represents a relatively higher proportion of the energy consumption of the whole annual building energy consumption. In international practice, energy saving operation is gaining ground. Here, this book is related to this topic, in which it introduces methods for energy-efficient dimensioning and design of air-conditioning systems in generalized, practical cases.

Hivatkozás: https://mersz.hu/kassai-kajtar-air-conditioning//

BibTeXEndNoteMendeleyZotero

Kivonat
fullscreenclose
printsave