VENTBOX 300

Apartments and family houses up to 200 m²

The VENTBOX 300 central heat recovery system is designed with an emphasis on modern technology, including a user-friendly solution for keeping the air in your home fresh and healthy. The unit achieves ideal parameters and is suitable for providing optimum performance and comfort in family houses up to 200 m². The unit is equipped with an advanced air purification system that effectively removes allergens and pollen from the air. It also ensures efficient exhaust air extraction with the possibility of dehumidifying the air from water vapour. The unit has low energy consumption. It also reduces the excessive presence of CO₂ in the room.

Optimum version
This is an innovative and powerful heat recovery unit designed to optimally achieve maximum performance while ensuring economic efficiency. The unit is equipped with all the necessary technical equipment to ensure efficient operation and optimization of all performance parameters.
Premium version
This is a more sophisticated version of the unit, which is equipped with unique EC motors with a constant flow function to compensate for pressure losses (e.g. when air filters become clogged). With these EC motors, the unit can operate more efficiently and economically; this has a positive effect on the overall dynamics as well as the economy when using the heat recovery system. The Premium version unit can automatically compensate for pressure loss in the system, e.g. when the air filters become clogged. At the same time, it ensures uniform ventilation and high heat recovery efficiency. The Premium unit is equipped with a front design cover.

Technical parameters Demand

Fresh air without allergens and pollen
Possibility of intensive extraction
Radon-free house

Recommended area	up to 200 m²
Energy class	A+
Installation option	Floor mounting, wall mounting/left or right variant
Dimensions (h × w × d)	750 × 790 × 625 mm
Weight [kg]	30.2 kg Optimum version; 32.5 kg Premium version
Voltage	230 V AC/50 Hz
Electric current without preheating [A]	0.7 A
Electric current including preheating [A]	4.6 A
Max. input power of the unit without preheating [W]	118 W
Max. preheating input power [W]	850 W
Total power input	968 W
IP coverage	30
Air flow [m³/h]	60–300 m³/h
Maximum airflow in BOOST setting [m³/h]	300 m³/h
Reference air flow [m³/h]	210 m³/h
Displacement pressure [Pa]	50–400 Pa
Acoustic energy L_WA [m³/h/Pa/dB]	210 m³/h/50 Pa/42.9 dB
Heat transfer efficiency/Flow rate	86 %/300 m³/h; 88 %/210 m³/h; 93 %/60 m³/h
Electrical input (without preheating)	88 W/300 m³/h; 31 W/210 m³/h; 16 W/60 m³/h
∅ of the connection necks [mm]	180 mm
Type of pipe for condensate drainage	HT DN 32 mm
Specific power consumption SPI* W/m³/h	0.29 W/at reference airflow 210 m³/h and disposition pressure of 50 Pa
Max. number of all sensors (CO₂/RH/RADON …)	9
Connector for fire sensor or EPS connection	Yes
Automatic frost protection	Yes
Bypass function (exchanger bypass)	Yes
Shock ventilation	Yes
Weekly time mode	Yes
Measuring energy consumption	Yes
Modbus TCP/IP communication	Yes
Modbus RTU communication	Yes
Analogue input	2
Digital input	1
EC motors with a constant flow function	Premium version
Filter clogging indicator based on time interval	Yes
Wire pre-filter	Yes
Filter clogging indicator based on filter pressure drop	Premium version
Filters supply/exhaust (% of particles captured in a given filter class) Optimum version	M5 ePM10 55 % (F7 pollen/odour optional)	M5 ePM10 55 % (F7 pollen optional)
Filters supply/exhaust (% of particles captured in a given filter class) Premium version	F7 pollen/odour ePM1 70 % (F7 odour optional)	F7 odour ePM1 70 %
By default, the unit is supplied with a counterflow heat exchanger (HRV)

Enthalpy counterflow heat exchanger (ERV)

The enthalpy counterflow heat exchanger is an optional part of the heat recovery system which, in addition to heat recovery, also allows moisture recovery, thus supporting the maintenance of optimal indoor air humidity and thus improving the user comfort of apartments and residential buildings. These systems bring many benefits, including energy efficiency, reduced heating costs, and improved indoor air quality.

Working principle of the counterflow exchanger

_{(right-hand connection option)}

Main features and benefits

• Heat exchange – an enthalpy heat exchanger allows heat energy to be transferred from warmer exhaust air to cooler outdoor air, thereby increasing the temperature of the air entering the building in winter. This helps to reduce heating costs because the fresh air is heated passively during the exchange.

• Moisture exchange – in addition to heat, the enthalpy heat exchanger allows moisture transfer. This is important for maintaining optimum humidity indoors. The moisture in the exhaust air is transferred to the supply air, which can be useful in areas with extreme climatic conditions.

• Reduction of losses and pollution – the enthalpy heat exchanger also serves to separate the supply and extract air, preventing the transfer of pollution, dirt and unwanted odours from the outside into the building. This improves the indoor air quality.

• Energy savings – operation without the need to preheat the incoming air down to -5 °C.

Specifications with enthalpy exchanger VENTBOX 300 Optimum version, Premium version
Weight of the entire unit	33.7 kg Optimum version 36.0 kg Premium version
Energy class	A
Heat transfer efficiency/Flow rate	76 %/300 m³/h 80 %/210 m³/h 90 %/60 m³/h
Moisture transfer efficiency/Flow rate	54 %/300 m³/h 58 %/210 m³/h 75 %/60 m³/h

The enthalpy heat exchanger can be ordered separately or later;
after a very simple installation, the entire unit is upgraded with advanced technology.
Ordering code: VENTBOX 300: P-018

VENTBOX COMPONENTS, FILTERS, CONTROL, BY-PASS

VENTBOX components

The VENTBOX 300 unit is are available in right or left-hand versions and can be installed on the wall or on thefloor. In the case of floor mounting, we recommend that the unit be fitted with floor mounting spacer stands due to the installation of a dry trap in the bottom.

Basic specifications

1unit body made of durable XPS material with thermal insulation properties and compact cladding
• the sides are fitted with painted aluminium sheet metal white
RAL 9010 for Optimum and Premium versions, grey-silver
• back side galvanized sheet metal
2 front wall design cover (Premium version)
3 front door made of painted Al sheet metal white RAL 9010
4side door – service fan covers
5 filter closing caps
6filters for air purification
7 bypass damper including actuator

8 filter bypass
9PTC cell for air preheating
10 plate counterflow heat exchanger
11 • Premium version – fans with economical EC motor and constant flow
• Optimum version – EC fans
12control electronics and power supply of the unit
13 fan cover
14 heat exchanger cover
15 preheating cover
16 bypass damper actuator cover
17 control electronics cover
18air duct connection necks (∅ 180 mm)
19 control and information panel with keypad and LED indication
20irect evaporator in conjunction with an outdoor heat pump unit only VENTBOX 400 Comfort version
21 external Wi-fi antenna
22 analog and digital inputs
23 hanging anchor rail

24 closing cover of pre-filters

25 pre-filters for air cleaning

26 external filter box

filter clogging indicator based on time interval
condensate drain outlet on the bottom of the unit with 5/4" connection thread
dry trap WHB1 – DN 32 mm
separate temperature sensor for monitoring the preheating function
temperature sensors for monitoring the air temperature
at the outlets and inlets of the ventilation unity
power cord 250 V AC/10 A
energy label, package leaflet, assembly and installation instructions

Basic software functions

• automatic frost protection
• display of the current preheating performance
• automatic by-pass function (exchanger by-pass)
• manual by-pass control (in summer mode)
• option of manual defrosting of the heat exchanger (in winter mode)
• option to connect a fire sensor or electric fire alarm system (EPS)
• control via web interface in local network
• weekly time mode
• Modbus RTU communication
• control of ventilation power also in the application interface
• leaving the premises/holiday function
• Modbus communication with a higher-level system (e.g. LOXONE)
• indicative information on current electricity consumption
• BOOST shock ventilation
• user configurable connected sensors (CO₂, relative humidity, total volatile concentration)
• language versions CZ, EN, DE, FR

Optional specification

• enthalpy counterflow heat exchanger
• continuous manual P.R.T. control with wall-mounted remote control
• CO₂ concentration sensor
• relative humidity (RH) sensor
• radon concentration sensors
• TVOC and HCHO (volatile substances and formaldehyde) sensor
• INPUT filters (Optimum) F7 (ePM1 70 %)*
• EXHAUST filters (Optimum) F7 (ePM1 70 %)*
• by-pass filters for Optimum F7 (ePM1 70%)*
• carbon odour filters INPUT F7 (ePM1 70%)*
• insulation box (must be used if the unit is operated in an area
where the ambient temperature reaches max. 5 °C)
• spacer stands for floor mounting

_{* údaj v (%) říká, kolik částic v dané filtrační třídě filtr „zachytí“}

FILTERS

• Filtration class M5 – inlet (Optimum version only) – 513 × 94 × 39 mm, ePM10 55 %

• Filtration class M5 – exhaust (Optimum version only) –

513 × 194 × 39 mm, ePM10 55 %
• Filtration class M5 – By-pass (Optimum version only) – 535 × 74 × 39 mm, ePM10 55 %
• Filtration class F7 inlet – 513 × 194 × 39 mm, ePM1 70 %
• Filtration class F7 exhaust – 513 × 194 × 39 mm, ePM1 70 %
• Filtration class F7 By-pass – 535 × 74 × 39 mm, ePM1 70 %

Pre-filter

• Pre-filter G2 – standard for all versions – 276 × 154 × 28 mm, galvanized, washable

• Carbon filter F7/AC supply – 513 × 194 × 39 mm, ePM1 70%

• Pre-filter M5 (only when using carbon filter F7) – 276 × 154 × 38 mm, ePM10 55%

• Filter for filter box G2 (only when using an external filter box)
208 × 208 × 28 mm, galvanized, washable

CONTROL

Unit control via web interface

The home screen is used to view information, control and set up the VENTBOX 300. The middle part displays the current power of the
unit; information and status icons are below, then the current values are measured by the room sensors used by the unit (provided that
the sensors are connected to the heat recovery unit). The lower part contains buttons for operating and setting the heat recovery unit.

Control and information panel

The VENTBOX 300 can normally be operated via the web interface, but all basic service operations can also be performed manually
(by pressing the appropriate button) on the control panel located on the front of the device:

R a short press of the button to perform a reboot, which preserves all user and service settings of the device.
D a longer press of the button (5 s) to enter the factory settings, where the ventilation unit runs permanently at reduced power. At the same time, all user settings will be lost, including weekly program settings and network connections if previously made. The settings for the type of exchanger (ERV/HRV) and fan corrections remain unchanged. The ventilation unit goes back to AP mode including the login password set by the manufacturer.
F press the button (2 s) to set the new filter change interval. Use this only for filter changes!

Information LED
• green – power – flashing – connected to power (Standby mode), lit – device in operation
• blue – filters – lit or flashing request for filter change
• red – error – must check “Error messages”

By-pass mode

Bypass mode is one of the key components of VENTBOX central heat recovery units. This mode is enabled by a bypass flap equipped with a servo drive. In case of manual or automatic activation and based on defined temperatures in the web interface, the bypass flap allows bypassing the heat exchanger. The air extracted from the interior is deflected by the bypass flap, so that it does not pass through the heat exchanger, after which it is directly discharged outside the building and does not transfer thermal energy to the outdoor air brought into the unit.

Bypass mode is commonly used during summer operation, especially at night when the outdoor air is naturally cooler. This allows the temperature of the interior spaces to be effectively reduced without the need for active cooling. The bypass thus provides an effective way to ensure optimal thermal comfort in the interior during the warm summer months.

By-pass mode description

1. The principle of the by-pass modeI
–In active mode, warm air from the interior is directly discharged outside without heat exchange. The heat exchanger is deactivated in this mode with the help of a bypass flap, which prevents unwanted heating of the fresh air being supplied. Fresh cool air is blown into the interior.

2. Activation conditions
– Bypass is activated automatically if the temperature in the interior rises above the desired value set in the web interface. Once the desired temperature in the interior is reached, the bypass mode is deactivated and the unit switches back to the standard recovery mode. The web interface can also define the lowest possible temperature of the air supplied to the interior.

3. Protection and filtration
– For the correct function and protection of the system, the bypass flap is supplemented with a bypass filter. This protects the heat exchanger and motor from dust with impurities that may be contained in the air diverted from the interior when there is no air flow through the standard exhaust filter. The bypass filter is necessary to ensure long-term reliability and efficiency of the recovery unit.

Advantages of the by-pass flap

• Energy savings – reduces the need for active interior cooling in the summer.
• Increased comfort – allows the use of naturally cooler outdoor air to improve the indoor climate.

User functions that you can control

• ventilation shutdown – Standby mode (unit is not disconnected from a power supply)
• switching between automatic and manual mode (A/M)
• one-time reduction of ventilation power when leaving the building (holiday)
• short-term increase of ventilation intensity (BOOST mode)
• manual bypass flap switching (summer only)
• user device settings

REQUIREMENTS FOR OTHER PROFESSIONS

Electrical requirements Mandatory preparation Fixed power cables 3×2.5 with circuit breaker 16 A char. B from the switchboard to the heat recovery unit • Terminate with a 230 V AC/50 Hz socket no further than 1.5 m from the power socket of the heat recovery unit (the power socket is located on the top side, at the front edge of the heat recovery unit between the air duct connection necks). • Marking of the circuit breaker with the label “heat recovery”. • Do not block – bulk remote control! Optional preparation UTP cable from the home Wi-fi router to the heat recovery unit • Terminate with RJ 45 socket at the location of the heat recovery unit. This is used only in case of a weak Wi-fi signal, for possible connection of a Wi-fi router, and for Wi-fi signal amplification (it is not used for physical connection of the heat recovery unit). Intensive exhaust buttons “WC, Bathroom, Kitchen” • Bring UTP cable or J-Y(ST)Y 2×2×0.8 to all rooms with exhaust requirement (WC, bathroom, kitchen and other optional rooms). • Connect all wires from the intensive exhaust buttons in parallel and connect them to the recovery unit. • Terminate with a free cable with a reserve of min. 2 m, not farther than 0.5 m from the data terminal of the heat recovery unit and mark “WC button, Bathroom, Kitchen”, etc. • In the rooms, install a push button with a return to the original CO₂ and HYG sensors and continuous control panel (P.R.T.) • Bring UTP cable or J-Y(ST)Y 2×2×0.8 for sensors and P.R.T. to the required rooms, the wires must be connected in series according to the requirements of the technical design of the RS 485 bus – sensors communicate using Modbus RTU! • Terminate the cable with a margin of min. 2 m, at the furthest 0.5 m from the data terminal of the heat recovery unit (data terminals are always located between the necks facing the interior
Recommendations
• The CO₂ sensor for bedrooms or living rooms should be placed at the height of the switches. • Humidity sensors for bathrooms should be placed on the wall 10 cm below the ceiling. • Always leave a margin of at least 0.3 m on the continuous cables that connect the individual sensors in series. Smoke detector and supply air overpressure control • Lead UTP or J-Y(ST)Y 2×2×0.8 cables to the required room with air excess pressure or smoke detection requirements (room with fireplace, boiler room, etc.)	• Terminate the cable with a reserve of min. 2 m, no further than 0.5 m from the terminal block of the heat recovery unit (terminal blocks are located on the top side at the front edge of the heatrecovery unit between the connection necks) and mark as “smoke detector(s), air pressure relief”. • When installing smoke detectors, follow strictly the smoke detector manufacturer’s recommendations. • When selecting the push button air pressure control, a push button with ON/OFF function must be fitted.

ELECTRICAL CONNECTION The electrical power connection of the VENTBOX 300 is by means of a 1.8 metre power cable. All connector connections are located on the Control Panel, which is located on the top side between the air duct necks. This is also where the main unit switch with fuse is located. 1 The unit’s main power switch with a socket for mains cable connection and FST 5× 20 10 A/250 V fuse 2 Modbus – connection of RH, CO₂, TVOC, Radon sensors, P.R.T. 3 P.R.T. – analogue input for connection of external controller 4 AI2 – analogue input 5 DI1 – digital input for intensive exhaust buttons (bathroom, kitchen, WC) 6 Antenna used for wireless communication (connection to Wi-fi network)

Requirements for water installation Mandatory preparation Drain pipes HT DN 32 mm, 5/4" thread • Lead the HT DN 32 mm waste pipe, fit it with a dry trap and terminate it near the condensate drain of the heat recovery unit (the condensate drain is located on the bottom side of the heat recovery unit). • It is necessary to ensure a free outflow with respect to the overall gradient of the waste water system (min. 3 %).	Requirements for construction Mandatory preparation • Supply optional air ducts ∅ 180 mm or ∅ 160 mm (when using reducer). • Make the necessary penetrations through walls, floors and ceilings. • Ensure sufficient handling space according to the chosen right/left variant and the connection (to the ceiling / under the ceiling)!

ASSEMBLY


Connection under the ceiling – left variant	Connection through the ceiling – left variant
	Connecting air ducts – left variant view from above


Connection under the ceiling – right variant	Connection through the ceiling – right variant
Connecting air ducts – right variant view from above
	Dimensions in mm. Technical changes reserved.

ORDERING CODES

Example of ordering code: VB2-0300-BC-OHR
Second generation VENTBOX 300 unit for central air distribution, with standard EC motors of the Optimum version, standard heat exchanger and right-hand connection.

VENTBOX	Generation		Volume flow		Design	Heat recovery unit type		Model / Type	Exchanger type	Connection option
V B	2	-	0300	-	B	C	-	O	H	R
					Box	Centralized		O – Optimum P – Premium	H – standard E – enthalpy	R – right L – left

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VENTBOX 300

Enthalpy counterflow heat exchanger (ERV)

Working principle of the counterflow exchanger

VENTBOX COMPONENTS, FILTERS, CONTROL, BY-PASS

VENTBOX components

Basic specifications

Basic software functions

Optional specification

FILTERS

Pre-filter

CONTROL

Unit control via web interface

Control and information panel

By-pass mode

By-pass mode description

Advantages of the by-pass flap

User functions that you can control

VENTILATION PERFORMANCE

VENTBOX 300

– available ventilation capacity

ACOUSTIC PARAMETERS

REQUIREMENTS FOR OTHER PROFESSIONS

Electrical requirements

ELECTRICAL CONNECTION

Requirements for water installation

Requirements for construction

ASSEMBLY

ORDERING CODES

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