RDZ UC 500-MHE Technical document

Air Handling Units
TECHNICAL / INSTALLATION MANUAL
Residential Dehumidifier with VMC System
Unit Comfort UC 500-MHE
FAG0CA031BZ.00
07/2019
bit.ly/rdzwebsite

DUCTABLE AIR HANDLING UNIT FOR FRESH AIR VENTILATION AND
HEAT RECOVERY mod. UC 500-MHE
SUMMARY
TRANSPORT AND STORAGE 2
DESCRIPTION OF THE MACHINE AND USE 2
DESCRIPTION OF OPERATIONS 3
DIMENSIONS 5
INSTALLATION 6
CONNECTIONS 8
START-UP AND COMMISSIONING 11
ROUTINE MAINTENANCE 15
EXTRAORDINARY MAINTENANCE 15
WARNINGS FOR THE CORRECT DISPOSAL OF THE PRODUCT 15

2
CONTENTS OF THE PACKAGING
The UC 500-MHE unit is packed onto a wooden pallet, and protected by a cardboard box. The
packaging contains:
1 UC 500-MHE unit;
1 use and maintenance manual.
Size of the packaging: 98x137x 53(h) cm;
Gross weight 115 kg
TRANSPORT AND STORAGE
IMPORTANT: The box must be transported on a pallet and handled using mechanical means;
on-site handling and transport must be carried out by suitable means, taking into consideration
the weight and dimensions of the packaging, so as to prevent the machine from being damaged
or from falling. A fall of even just a few centimetres may damage the contents. The box must
never be placed upside-down or overturned. If this happens, it must be put back in the correct
horizontal conditions for at least three hours before installation.
Store the boxes in horizontal position and not upside down; up to 3 boxes can be stacked on
top of one another. Acceptable environmental conditions: temperature -10°C ÷ 50°C, relative
humidity less than 90%.
SAFETY WARNINGS
- The machine contains pressurized refrigeration gas. The room or area must be aired in
the case of gas leakage from one or more machines.
- The gas in the machine may develop toxic components in the event of fire.
- Contact with the fan outlet may cause injury.
- Electrical connections must be carried out by qualified and skilled technicians as per the
laws in force.
- Defects regarding pipework, hydraulic connections and shut-off valves may lead to
dripping or splashing of water, with consequent damage to objects, as well as dangerous
situations in the presence of electricity.
- Suitable lifting systems and Personal Protective Equipment (i.e. gloves, hard hats) must
be used while handling the machinery during installation.
DESCRIPTION OF THE MACHINE AND USE
In combination with surface cooling system, the UC 500-MHE unit is able to perform air
handling according to the different seasonal requirements and environmental well-being.
Functions may be:
- fresh air ventilation, both during summer and winter, with high efficiency heat recovery;
- fresh air ventilation without heat recovery (free-cooling);
- air dehumidification during summer with temperature control over the air supplied into the
room;
- summer cooling with or without dehumidification (using water from the radiant system);
- winter heating using hot water from the radiant system.
The galvanized sheet metal frame of the machine houses the finned coils for air handling, the
refrigeration circuit for dehumidification, the extract air filter, the drain pan, the supply fan and
the electrical control panel.

UC 500-MHE – INSTALLATION, USE AND MAINTENANCE MANUAL
3
DESCRIPTION OF OPERATIONS
The following figure shows the machine layout, the main components and the air flows.
The air flow-rate can be set from the control panel. The fans are automatically set to the speed
necessary to overcome the pressure drop in the ductwork.
The machine can work with two air flows: the one for the fresh air ventilation with heat recovery,
involving the air to air counter-current heat exchanger (1), and the one for room air recirculation.
The renewal and recirculation flows can be combined or not, as per the flow rate and type of
treatment to be carried out on the incoming air.
There is also a duct which is controlled by a motorized damper and allows the intake of the
outdoor air without passing through the heat exchanger. In this way, free cooling can take place.
The bypass opens automatically when the appropriate input occurs and when the outdoor
temperature is below the set limit.
1 – Air to air heat exchanger
2 - Cooling compressor;
3 - Water finned coil;
4 - Cooling evaporator;
5 - Freon/air condenser;
6 - Freon/air discharge condenser;
7 – Air supply fan;
8 - Air exhaust fan;
9 - Electrical switchboard
10 - Room air recirculation damper;
11 - Fresh air intake damper;
12 - Stale air extract damper;
13 - Auxiliary air intake damper;
14 – Recovery bypass damper.
INDOOR
OUTDOOR

4
The following types of air handling can be carried out:
- fresh air ventilation with high efficiency heat recovery, with possible winter heating or
summer cooling;
- fresh air ventilation with free-cooling, that is without heat recovery, both in summer and in
winter;
- air recirculation in winter, with possible heating;
- air recirculation in summer, with cooling, dehumidification or cooling + dehumidification;
- air recirculation with partial fresh air ventilation, together with all treatments provided for
during recirculation.
Air flow rate can be set as follows:
- air supply flow rate from 300 m³/h to 500 m³/h;
- fresh air ventilation flow rate from 160 to 300 m³/h.
- free-cooling flow rate from 160 to 300 m³/h.
OPERATION OF COOLING CIRCUIT
COOLING
The finned coil (3), which is connected to the radiant system, enables summer cooling and
winter heating.
The temperature control over the outgoing air is carried out by the machine by means of the
mixing valve in the water circuit.
1 Cooling evaporator;
2 Cooling compressor;
3 Water finned coil;
4 Excess heat discharge condenser;
5 Freon/air condenser;
6 Air exhaust fan;
7 Air supply fan;
PCB Printed Circuit Board;
E1
-
2
Electronic expansion valve.
outgoing
AIR
incoming
AIR

UC 500-MHE – INSTALLATION, USE AND MAINTENANCE MANUAL
5
DEHUMIDIFICATION AND COOLING
The finned coil (3) supplied with the water coming from the radiant system, cools down the air,
while the cooling evaporator (4) performs further cooling and dehumidification.
The refrigeration circuit is made up of two condensers connected in parallel: in addition to the
an air-cooled condenser (5) a second condenser is cooled by the outgoing air flow (6), thus
releasing the condensation heat outwards. In carrying out this process the machine uses both
exhaust stale air and an additional air flow coming from outside.
The two electronic expansion valves (E) allow to distribute the condensation heat between in
the incoming and outgoing air in the desired proportion; this enables to have outgoing air at the
desired temperature between maximum cold and neutrality.
The levels of outgoing air temperature that can be set are:
- neutral summer temperature;
- summer cooling temperature;
- neutral winter temperature;
- winter heating temperature.
PLEASE NOTE: the cooling system cannot be started up during winter or in fresh air ventilation
mode only.
DIMENSIONS

6
INSTALLATION
SAFETY WARNINGS
Installation and maintenance must be carried out only by qualified personnel.
The machine must be protected from frost.
Hydraulic and electrical systems, along with the installation position, must comply with the
safety rules and regulations in force in the country where the unit has been installed. Read the
instructions in this manual carefully before working on the machine.
The sizing of the fixing system is the sole responsibility of the installer.
The machine contains pressurized refrigeration gas. The room or area must be aired in case of
gas leakage from one or more machines. The gas in the machine may develop toxic
components in the event of fire.
Do not remove the protection and safety devices.
This appliance is not suitable for the use in explosive or potentially explosive environments.
Defects regarding pipework, hydraulic connections and shut-off valves may lead to dripping or
splashing of water, with consequent damage to objects, as well as dangerous situations in the
presence of electricity.
Requirements prior to installation
The following conditions must be in place before installing the machine:
-inflow and return pipework for the water from the radiant circuit shall be equipped with
two shut-off valves for the disconnection of the line;
-drainage for condensed water; two separate siphons, each for its own drain, shall be
installed to avoid the suction of air in the discharge pipe;
-the installer shall provide electric cables for the power supply, PE protective conductor
(earthing conductor) and operating consent signals.
CONNECTIONS CHARACTERISTICS CONDITIONS
Refrigerated water Temperature 15°C;
Pressure 1.5 m w.g. T min. 12°C, max. 18°C;
Power supply 10 A 230V – 50Hz - 1ph
Condensate drainage Capacity 15 l / h,
minimum gradient 3% 3 connections required
Aeraulic ductwork Minimum diameter as
per the air sockets of
the machine
The pressure drops of the ducts, summing
the inflow and extract flows, must not
exceed the available pressure of the unit

UC 500-MHE – INSTALLATION, USE AND MAINTENANCE MANUAL
7
Positioning
Minimum distances for installation
WHILE ESTABLISHING THE CORRECT AREA FOR INSTALLATION YOU SHALLTAKE INTO
ACCOUNT THAT DURING ITS WORKING LIFE THE APPLIACE MAYREQUIRE:
-ROUTINE MAINTENANCE;
-REPLACEMENT OF COMPONENTS;
-REPLACEMENT OF THE WHOLE UNIT
For correct maintenance or repair
operations, there must be a free area
around the machine according to the
measurements shown in the figure below.
These areas, including the space
occupied by the machine, must be freely
accessible for maintenance.
The machine must be installed inside
buildings, positioned horizontally.
Operation in an inclined position of
more than 1% may cause water
leakage or may damage internal
devices.
UP
DOWN

8
CONNECTIONS
KEY TO SYMBOLS
1 - cold/hot water input;
2 - cold/hot water output;
3 - electrical input connections;
4 - hydraulic circuit vent;
5 - dehumidifier condensate drain;
6 - winter condensate drain;
7 - summer condensate drain;
8 - stale air exhaust;
9 - outdoor air intake;
10 - stale air extract;
11 - air recirculation intake;
12 – air supply to the rooms;
Water circuit pipework connection
Shut-off valves must be inserted in the refrigerated water pipes in order to disconnect the
system from the machine.
After connection to the system, a water tightness check must be carried out on both the
connections and the machine in order to avoid any damage for the area below the machine.
Condensate discharge
There are three condensate drains: two drains are for the summer and winter recuperator
condensate, one for the summer condensation of the dehumidifying section.
The condensate drains must not be connected directly tothe sewer system since there could be
unpleasant odours during the period when the machine is not used.
≥9%
8 cm
Discharge NOT
in ascent!
OK OK
Winter
drain
Summer
drain
Dehumidier
drain

UC 500-MHE – INSTALLATION, USE AND MAINTENANCE MANUAL
9
Aeraulic connections
The machine is equipped with metal spigots, which protrude about 4cm and which make it
possible the connection with flexible or rigid ducts, provided that they are equipped with gaskets
to avoid air leaks and unpleasant noise. Spigot diameters are as follows:
supply and recirculation Ø 200
fresh air intake and air exhaust Ø 200
stale air from bathroom/kitchen Ø 150
PLEASE NOTE: the real diameter of the air spigots is approximately 1-2 mm less than the
nominal diameter.
ELECTRICAL CONNECTIONS
CONDUCTOR SECTION
The electric power supply line and the isolating devices must be decided by qualified staff
responsible for the electrical design. In any case, the cable must have a minimum cross-section
of 3x1.5 mm², F + N + PE.
The following diagram shows the terminals which are available for connections:
-the machine must be connected to an electric power supply;
-a 4-wire connection provides the control panel with both the 24VDC power supply and
the serial communication. This connection cable must have a minimum cross-section of 0.5
mm² and must be shielded.
On-board electronic control panel
230V
p
ower su
pp
l
y
Connection to the control
Red led means tensio
n
Green le
d
ADDRESS CONFIGURATION
Unit 1 Unit 2
MODBUS

10
TECHNICAL DATA
Power supply V/Ph/Hz 230 - 1 - 50
Weight kg 105
Total dehumidification capacity
(Outdoor temperature 35°C, 50% R.H.) l/24h 74.1
W 2090
Useful dehumidification capacity (referring to
recirculation, room temperature at 26°C, 55% R.H.) l/24h 31.2
W 880
Useful cooling capacity (referred to recirculation,
room temperature at 26°C, 55% R.H.) W 2580
Maximum electrical power use of compressor W 780
Required water flow l/hr 500
Water circuit load loss kPa 11
Maximum cooling capacity required by water circuit
(outdoor air at 35°, 50% R.H., max flow-rate in only
Ventilation and Ventilation+Recirculation mode) W 2050
Power consumption for the air supply fan
(min - max) W 20 - 160
Flow rate of the air supply fan (min - max) m³/h 160 - 500
Available pressure of the air supply fan Pa 260
Power consumption for the air exhaust fan
(min - max) W 20 - 160
Flow rate of the air exhaust fan (min - max) m³/h 160 - 500
Available pressure of the air exhaust fan Pa 260
Energy efficiency during winter operation (20°C -
50% R.H. indoor, -5°C - 80% R.H. outdoor) flow rate 160 m³/h 91.70%
flow rate 300 m³/h 87.50%
Energy efficiency in summer operation (26°C -
65% R.H. indoor, 35°C - 50% R.H. outdoor) flow rate 160 m³/h 86.70%
flow rate 300 m³/h 80.40%
Sound pressure level
(Open field, distance of 1m) dB(A) 48

UC 500-MHE – INSTALLATION, USE AND MAINTENANCE MANUAL
11
START-UP AND COMMISSIONING
All hydraulic, aeraulic and electrical connections must be carried out before starting up the
machine. Check the availability of refrigerated water and the absence of water leakage from the
connections and from the machine.
The electronic control panel has a red LED and a green LED, which show the general status of
the unit.
Functions that can be activated via digital inputs are:
- current season;
- fresh air ventilation with heat recovery (yes, no, automatic with time slots);
- summer dehumidification;
- summer cooling;
- winter heating;
- free-cooling;
- flow-rate attenuation compared to normal setting.
Settings that can be carried out on the keyboard are:
- activation of functions (as an alternative to digital input);
- current time;
- current season (as an alternative to digital input);
- flow rate for air supply in Ventilation and Ventilation+Recirculation mode;
- standard air supply temperature and air temperature for heating and cooling;
- automatic time slots for fresh air ventilation (max. 4);
- time slots for flow-rate attenuation (max. 4);
Machines equipped with a Control Panel can also read the levels of the temperature sensors
which the machine is equipped with. These values can be useful in the testing phase or while
verifying the correct operation.
Further details can be found in the manual: “UC 500-MHE Control Panel”.
When the machine is powered up, the green
LED lights up, remaining lit for about 90
seconds. During this period the control panel
carries out some checks. Later, the red LED
lights up, indicating the presence of voltage;
the machine is therefore ready to receive input
from the control panel and to perform the
required functions.
PLEASE NOTE: After the start-up time of 90
seconds, the green LED is to be considered as
input sent to the cooling compressor. If it is
continuously lit, the compressor is functioning,
if it is flashing, there is a request for operation
but the compressor is not activated because it
is waiting for the start timer or because there is
some fault.

12
SUMMER OPERATING MODE
FRESH AIR VENTILATION
AIR DEHUMIDIFICATION
FRESH AIR VENTILATION + DEHUMIDIFICATION
FRESH AIR VENTILATION + SENSIBLE COOLING
Both fans are running and
carrying out fresh air
ventilation: the outdoor air is
cooled down by the heat
exchanger by using the
exhaust air first, and then by
the refrigerated water
circulating in the finned coil.
The compressor and the
supply fan are running; the
room air is dehumidified and
supplied into the room at the
set temperature. If excess
heat must be removed, the
exhaust fan intakes and
expels an external air flow,
which is warmed by the
discharge coil.
The compressor and both
fans are running. The inflow
air is treated by the whole
group of coils. The air flow
rate can be set from 300 to
500 m³/h, while the flow rate
for the fresh air ventilation
can be set from 160 to 300
m³/h.
INDOOR
INDOOR
INDOOR
OUTDOOR
OUTDOOR
OUTDOOR

UC 500-MHE – INSTALLATION, USE AND MAINTENANCE MANUAL
13
HEAT RECOVERY BYPASS
WINTER OPERATING MODE
FRESH AIR VENTILATION
AIR RECIRCULATION
Both fans are running and
carrying out the fresh air
ventilation; the outdoor air is
warmed up by the heat
exchanger first, by using the
exhaust air, and then by the
hot water circulating in the
finned coil.
The supply fan is running; the
room air extracted and
supplied to the room again at
the set temperature. The
outgoing temperature is
regulated by modulating the
flow rate of the hot water
circulating in the finned coil.
The flow rate for the supply
air can be set from 300 to 500
m³/h
Both fans are running, the
intake air damper is closed and
the bypass damper is open.
The inflow air is warmed up by
the water coil.
The air flow rate can be set
from 160 to 300 m³/h.
INDOOR
INDOOR
INDOOR
OUTDOOR
OUTDOOR
OUTDOOR

14
FRESH AIR VENTILATION + AIR RECIRCULATION
WINTER FREE-COOLING
The fans are both running.
The supply air is warmed up
by the water coil. The intake
air is pre-heated by the heat
exchanger by using the
exhaust air. The supply air
flow rate can be set from
300 to 500 m³/h, while the
flow rate for fresh air
ventilation can be set from
160 to 300 m³/h.
The fans are both running,
the intake air damper is
closed and the bypass
damper is open. The water
circuit of the finned coil is
closed. The air flow rate can
be set from 160 to 300 m³/h.

UC 500-MHE – INSTALLATION, USE AND MAINTENANCE MANUAL
15
ROUTINE MAINTENANCE
Routine maintenance involves the cleaning of the air filters.
The filters should be checked every 90 days.
To remove and clean the filters:
- unscrew the knobs that fix the filter cover, near the air spigots;
- remove the cover carefully;
- the filters can now be removed and cleaned using soap and water or by blowing with
compressed air:
Please note: the filters are G4 class; if finer filtration is needed, or in case of very dusty air, the
supplied filters could be inadequate. The system can be set up with air filters which shall be
installed out of the machine, depending on the needs of the system.
Removal of air filters
EXTRAORDINARY MAINTENANCE
Extraordinary maintenance involves the cleaning of the heat exchanger.
The exchanger should be checked every two years.
For removal and cleaning:
- Remove the air filter (see previous instructions)
- Open the panel downwards by using the 4 side hooks
- Remove the heat exchanger carefully:
- Cleaning can now be carried out using soap and water or by blowing with compressed air.

16
WARNINGS FOR THE CORRECT DISPOSAL OF THE PRODUCT
According to the provisions of the following European directives 2011/65/EU, 2012/19/EU,
and 2003/108/CE, concerning the restriction of the use of certain hazardous substances
in electrical and electronic equipment, as well as waste disposal.
The crossed out wheelie bins symbol on the equipment indicates that, at the end of its useful
life, the product must be collected separately from general waste.
The refrigerating gas contained within it must be recovered separately by specialised personnel
and sent to collection centres; the lubrication oil for the compressors must also be recovered
and sent to collection centres; The structure and the various components, if they can no longer
be used, must be demolished and divided up according to the type of product: this is particularly
important for the copper and aluminium components, which are included in the machine in
moderate quantities. Therefore, at the end of its useful life, the user must take the equipment to
a designated electrical and electronic waste collection point , or return it to the dealer that,
against the purchase of an equivalent appliance, it is obliged to collect the product for disposal
free of charge.
Appropriate differentiated waste collection for subsequent recycling, treatment and
environment-friendly disposal of the discarded equipment helps preventing possible negative
environmental and health effects and encourages recycling of the component materials of the
equipment.
Illegal disposal of the product by the user entails the application of sanctions provided by the
regulations in force.

Air Handling Units
TECHNICAL / INSTALLATION MANUAL
Residential Dehumidifier with VMC System
Unit Comfort UC 500-MHE
FAG0CA031BZ.01
09/2019
bit.ly/rdzwebsite