- (01-17) -
4. DESIGN SECTION
4-1. ABOUT HEAT EXCHANGE UNIT
4-1-1. BASIC ENGIN
BASIC PRINCIPLE AND
STRUCTURE OF THE HEAT
EXCHANGER
Basic principle of a heat exchanger
Warm and moist
ai
r
Heat-exchange element
HeatHumidity
Cold and
dry air
Function of a heat exchanger
Winter
Mechanism of a heat exchange element
The heat exchange element can allow the exhaust air from
inside and the fresh air from outside to transmit temperature
Indoor exhaust
Outdoor inlet
Mechanism of total heat ex-
change
HeatIndoor air
upply at 14
Humidity s
Cold air at
0
Indoor air
supply
Outdoor
exhaust
Outdoor
exhaust at 6 Humidity
Heat exchange
element
0°C
6°C 14°C
20°C
Heat exchange
ratio at 70%
Warm air at
20
Heat
ADVANTAGES OF THE HEAT
EXCHANGE ELEMENT
The height of the heat exchange element
reduced by 20%
entire unit much thinner from 287mm
performance as in the conventional
Comparison of heat exchange elements
C tross-flow elemen Counter-flow ele-
ment
While airflows are directly crossed in the cross-flow ele-
ment, the counter-flow element allows airflow to be retained
for longer time (or longer distance). In this manner, the
thinner system can maintain the heat exchange perform-
ance attained b
y
its thicker counterpart.
6%
The adoption of the counter-flow element has improved
Long-life heat exchange element
does not require regular cleaning of the heat exchange
element.
cross-flow element
After cleaning the
cross-flow element
The counter-flow element
Heat exchange element with
extended life
The cross-flow element
requires regular clean-ups.
A
irflow
resistance
Changes in airflow resistance
with the
y
ears of use
Cleaned
Used
Initial
level
1st
year
2nd
year
3rd
year
4th
year
5th
year
6th
year
7th
year
8th
year
9th
year
10th
year
Service year
The counter-flow element requires no regula
r
clean-up, as the resistance level hardly rise.
pe ) rp ) r
Before cleaning the
Long-life heat exchange element
Conventional element
(corrugated structure)
With the above features, airflow resistance affecting service life hardly rises.
The end section is finished with the resin-formed
structure characterized by robustness
Bigger air-course per cell
The fin structure is seldom crushed or damaged.
Dirt and dust are seldom attached.
New-type element
Heat exchanger
p
l
ate (pape
r
)
Hydraulic
diamete
r
Spacing plate
(paper)
Spacing rib (resin)
Heat exchanger
p
late
(p
a
p
er
)
Hydraulic
diamete
r
