7
English
• Setting “off after 3 hours” and “on after 4 hours” will
↓
• Operation will stop after 3 hours.
Operation will then start in 1 hour from the time it stopped.
3-3
NIGHTTIME FREE COOLING OPERATION
〈〈〈〈
AUTOMATIC HEAT PORGE FUNCTION AT NIGHT
〉〉〉〉
The nighttime free cooling is an energy-conserving function
which works at night when the air conditioners is off, reducing
the cooling load in the morning when the air conditioner is
turned on by ventilating rooms which contain office equipment
which raises the room temperature.
• Nighttime free cooling only works during cooling and when
connected to Building Multi or VRV systems.
• Nighttime free cooling is set to “off” in the factory settings;
so request your dealer to turn it on if you intend to use it.
Operation image
(a) Outside temperature
(b) Indoor temperature
(c) Set temperature
(d) Operating state of Air conditioner
(e) Operating state of Total heat exchanger
EXPLANATION OF NIGHTTIME FREE COOL-
ING OPERATION IMAGE
The unit compares the indoor and outdoor temperatures after the
air conditioning operation stops for the night. If the following condi-
tions are satisfied, the operation starts, and when the indoor tem-
perature reaches the air conditioning setting, the operation stops.
<Conditions>
(1) the indoor temperature is higher than the air conditioning
setting and
(2) the outdoor temperature is lower than the indoor temperature,
If the above conditions are not satisfied, reevaluation is made
every 60 minutes.
NOTE
• The night purge operation works when the HRV unit is off.
Therefore, it is not possible to stop the night purge opera-
tion, though the forced off is input from the optional control-
lers for centralized control.
4.
MAINTENANCE
(for a qualified service person only)
ONLY A QUALIFIED SERVICE PERSON IS ALLOWED TO
PERFORM MAINTENANCE
WARNING
• BEFORE OBTAINING ACCESS TO TERMINAL DEVICES,
ALL POWER SUPPLY CIRCUITS MUST BE INTERRUPTED.
• To clean the HRV, or maintenance be sure to stop operation,
and turn the power switch off. It may cause electrical shock
and it is very dangerous to touch the rotating part.
• Do not wash the HRV with water.
Doing so may result in an electric shock.
CAUTION
• Use gloves when cleaning.
Cleaning without gloves may cause injury.
• Watch your step.
Use caution, as this requires working in high places.
• Do not use benzene or thinner to clean the outside surfaces
of the air conditioner.
This may cause cracks, discoloration, or machine trouble.
4-1
HOW TO CLEAN THE AIR FILTER
Clean the air filter when the display shows “
”
(TIME TO CLEAN AIR FILTER).
It will display that it will operate for a set amount of time.
CLEANING FREQUENCY
AT LEAST ONCE EVERY YEARS
(FOR GENERAL OFFICE USE)
(CLEAN THE MORE FREQUENTLY IF NECESSARY.)
• Increase the frequency of cleaning if the unit is installed in a
room where the air is etermely contaminated.
• If the dirt becomes impossible to clean, change the air filter
(Air filter for exchange is optional).
1. Detach the maintenance cover.
Go into ceiling through the inspection hatch, remove
binding metal of maintenance cover and take it off.
(Refer to figure 7)
2. Detach the air filter.
Take out from the heat exchange elements.
(Refer to figure 7)
3. Clean the air filter.
(Refer to figure 8)
Use vacuum cleaner A) or wash the air filter with water B).
A) Using a vacuum cleaner
B) Washing with water
When the air filter is very dirty, use soft brush and
neutral detergent.
After cleaning, remove water and dry in the shade.
NOTE
• Do not wash the air filter with hot water of more than 50°C,
as doing so may result in discoloration and/or deformation.
• Do not expose the air filter to fire, as doing so may result in
burning.
• Do not use gasoline, thinner, or other organic solvents.
This may cause discoloration or deformation.
4. Fix the air filter.
If the air filter is washed, remove water completely and
allow to dry for 20 to 30 minutes in the shade. When dried
completely, install the air filter back in place.
(Refer to figure 9)
NOTE
• Be sure to install the air filter after servicing.
(Missing air filter causes clogged heat exchange element.)
The air filter is an optional item and the replacement is avail-
able.
5. Install the maintenance cover.
Refer to the section (4-1, 1).
∗
Consult your dealer if you want to change the time set-
ting for when the filter sign goes on.
OFF
ON
ON
OFF
OFF
OFF
40
30
20
(time)
Following morning
22:00
24:00
(d)
(e)
Oper
ating state
T
emper
ature (˚C)
Nighttime free cooling operation
(a)
(b)
(c)
For remote controllers which display the filter sign,
turn on the power after maintenance, and press the
filter sign reset button.
3P034927-5_En.fm Page 7 Sunday, October 30, 2005 3:24 PM
