VENTBOX 800 Public

Public buildings and schools

The decentralized heat recovery unit VENTBOX 800 Public is designed for installation in enclosed spaces of school buildings and other public spaces. It meets strict hygienic limits for acoustic emissions and air filtration. Ventilation performance, low acoustic emissions, compact dimensions and efficient heat recovery allow installation even in buildings, where extensive air ducts cannot be built.

The VENTBOX 800 Public ventilation unit has its own solution for connecting exterior air inlets, for example through a window infill. The termination of air ducts on the outside of the building is always done with a requirement for aesthetic appearance and functionality. The ventilation unit is equipped with an efficient heat exchanger and reduces heat losses that occur during conventional ventilation ‘only by opening windows’ or other economically and technically unsuitable methods of ventilation. It ensures a permanent reduction in CO₂ concentration and maximum elimination of outdoor odors using carbon filters and brings the comfort of fresh clean air. The installation of a unit with an enthalpy exchanger does not require connection to a waste pipe for condensate drainage.

Technical parameters Demand

Efficient exhaust air removal
Fresh air without allergens and pollen
Radon-free house

Recommended area	up to 600 m²
Energy class	A+
Installation option	Floor mounting
Dimensions (h × w × d)	2 050 × 1 005 × 740 mm
Weight [kg]	152 kg
Voltage	230 V AC/50 Hz
Electric current without preheating [A]	1.5 A
Electric current including preheating [A]	12 A
Max. input power of the unit without preheating [W]	318 W
Max. preheating input power [W]	2 550 W
IP coverage	30
Air flow [m³/h]	120–800 m³/h
Maximum airflow in BOOST setting [m³/h]	800 m³/h
Reference air flow [m³/h]	560 m³/h
Displacement pressure [Pa]	50–100 Pa
Acoustic energy L_WA [m³/h/Pa/dB]	560 m³/h/50 Pa/39 dB
Heat transfer efficiency / Flow rate	82 %/800 m³/h; 82 %/560 m³/h; 81 %/120 m³/h
Electrical input (without preheating)	263 W/800 m³/h; 105 W/560 m³/h; 20 W/120 m³/h
∅ of the connection necks [mm]	250 mm
Type of pipe for condensate drainage	HT DN 32 mm
Specific power consumption SPI	0,19 W/m³/h
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	Yes
Filter clogging indicator based on time interval	Yes
Wire pre-filter	Yes
Filter clogging indicator based on filter pressure drop	Yes
Filters supply/exhaust (% of particles captured in a given filter class)	F7 pollen/odour ePM1 70 % (F7 AC optional)

Enthalpy Counterflow Heat Exchanger (ERV)

Enthalpy counter-flow plate heat exchanger (ERV) 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

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 800 Public: P-029

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 800 Public
Energy class enthalpy heat exchanger	A
Weight of the entire unit	146,5 kg
Heat transfer efficiency / Flow rate	76 %/800 m³/h 78 %/560 m³/h
Moisture transfer efficiency / Flow rate	56 %/800 m³/h 63 %/560 m³/h

VENTBOX COMPONENTS, FILTERS, CONTROL, BY-PASS

VENTBOX components

Basic Specifications

1 compact casing
2 front service door with handles and locks
3 fan service door
4 acoustic panels
5 fans with efficient EC motors
6 fan covers
7 noise dampener
8 plate counterflow heat exchanger HRV
9 heat exchanger cover
10 external Wi-Fi antenna
11 cable route cover
12 air duct sockets
13 control and information panel
14 fuse case with fuse
15 control panel – analogue and digital inputs
16 external Wi-Fi antenna terminal
17 directional nozzle for air exhaust with coarse debris screen
18 air purification filters
19 filter closing caps

20 dry rap – condensate drain outlet at the bottom of the unit with 5/4" connection thread
21 adjustable travel
22 exterior connection fittings
23 fixing anchors
bypass damper including actuator
air preheating (3 PTC cells)
filter clogging indicator based on time interval
filter clogging indicator based on filter pressure drop
separate temperature sensor for monitoring the preheating function
temperature sensors for monitoring the air temperature at the outlets and inlets of the ventilation unit
connector for connecting fire sensor or electrical fire alarm system (EFS)
air exhaust with a screen to prevent foreign objects from entering
power cord 230 V AC / 16 A
package leaflet, assembly and installation instructions

Basic Software Functions

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

Optional Specification

• enthalpy counter-flow plate heat exchanger ERV
• vontinuous manual P.R.T. control with wall-mounted remote controller
• CO₂ concentration sensor
• relative humidity (RH) sensor
• radon concentration sensor
• combined TVOC and HCHO (volatile substances and formaldehyde) sensor
• carbon odour filters INPUT F7 AC (ePM1 70 %)- the figure in (%) tells how many particles in a given filter class the filter „captures“
• sheet metal air duct inserts
•adjustable travel

FILTERS

• Collapsible filter – F7 (ePM1 70%) – inlet 450 × 253 × 50 mm)
• Carbon filter, collapsible – F7 AC (ePM1 70%) – inlet 450 × 253 × 50 mm
• Collapsible filter – F7 (ePM1 70%) – exhaust / by-pass 642 × 254 × 28 mm

předfiltry 400

CONTROLS AND FUNCTIONS

Unit control via web interface

The home screen is used to view information, control and set up the VENTBOX 800. 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 800 Public 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 R to perform a reboot, which preserves all user and service settings of the device.

D a longer press of the button (5 s) D 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) F 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 bypass 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)
• user device settings
• manual by-pass flap switching (summer only)

REQUIREMENTS FOR OTHER PROFESSIONS

Electrical Requirements Mandatory preparation Fixed power cables 3×2.5 with a 16 A circuit breaker class B from the switchboard to the heat recovery unit • Terminate with a 230 V AC / 50 Hz socket not farther than 1.5 m from the power supply module of the heat recovery unit (the power supply module is located on the top of the unit, between the air duct sockets). • Mark the circuit breaker with a “heat recovery” label. • Do not block – bulk remote control! Optional preparation UTP cable from the local network Wi-fi router to the heat recovery unit • Terminate with a RJ45 socket at the location of the heat recovery unit. This is only used 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). Buttons for intensive extraction (BOOST) to the desired rooms • Lead a UTP or J-Y(ST)Y 2×2×0.8 cable to all rooms with exhaust requirement (bathroom, WC, kitchen, storage room, reception, server room 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 peripheral heat recovery unit and mark the button “Storage”, “WC”, “Bathroom”, etc. • In the rooms, install a push button with return to original position. CO₂ and RH sensors and continuous control panel (P.R.T.) • Lead a UTP or J-Y(ST)Y 2×2×0.8 cable 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 RS485 bus – sensors communicate using Modbus RTU. • Terminate the cable with a margin of min. 2 m, not farther than 0.5 m from the data terminal of the heat recovery unit (peripheral data terminals are always located between the sockets facing the interior). Recommendations • The CO₂ sensor (for places with a higher concentration of people) 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 a UTP or J-Y(ST)Y 2×2×0.8 cable to the required room with air pressure or smoke detection requirements (room with fireplace, boiler room, etc.). • Terminate the cable with a reserve of min. 2 m, not farther than 0.5 m from the terminal block of the heat recovery unit 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 800 Public is via a 2.5 metre power cable. All connector connections are located on the Control Panel, which can be found under the service door on the front of the unit. The power supply fuse and the main power supply module are also located here. 1 front service door used to protect the control panel 2 fuse box with fuse FST 6.3×32 16 A / ~ 230 V 3 control panel with analogue and digital inputs 4 Modbus – connection of RH, CO₂, TVOC, Radon, P.R.T. sensors 5 P.R.T. – analogue input for connection of external ventilation output controller P.R.T. 6 AI2 – analogue input 7 DI1 – digital input for intensive extraction buttons (to the required rooms) 8 sMA connector for external Wi-Fi antenna connection 9 antenna used for wireless communication (connection to Wi-Fi network)	Control Panel with Connection for Connectors

Requirements for Water Installation Mandatory preparation HT waste pipe – DN 32 mm, or 5/4" thread • Lead the HT DN 32 mm waste pipe, fit it with WHB1-32 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). • Keep in mind the required “inspection opening” and the possibility to disconnect the recovery unit from the waste. • 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 Air ducts ∅ 250 mm • Lead air ducts according to the selected configuration of the heat recovery unit and the corresponding positioning of air duct connections. • Keep in mind the overall location of the heat recovery unit in the building (wall / drop ceiling / floor mounting). • Ensure sufficient handling space for installation and servicing with regard to the location of the heat recovery unit according to the selected variant and connection. Anchor holes • With regard to the chosen mounting variant and weight. General Requirements Other requirements are governed by the project documentation.

ASSEMBLY

Floor Mounting – connection under the ceiling beam

Floor Mounting – connection through the ceiling beam

View from above
Installation in the corner of the room with a direct elbow connection

picti info * The distance of the anchoring element required for safe placement is 110 mm.
This must be taken into account during installation.

View from above
Free installation in the space with a flexible supply

The unit must always be placed on a flat surface with sufficient load capacity,
ensure its correct orientation with respect to the air ducts and the overall resulting
gradient of the waste removal system (min. 3°).

ORDERING CODES

Example of ordering code: VB1-0800-PD-PHL
VENTBOX 800 Public, a first-generation unit for decentralized air distribution, EC constant flow motors Premium version, with standard counterflow plate heat exchanger and left-hand side connection.

VENTBOX	Generation		Volume flow		Design	Heat recovery unit type		Model / Type	Exchanger type	Connection option
V B	1	-	0800	-	P	D	-	P	H	L
					Public	Decentralized		P - Premium	H - standard E - enthalpy	L - left

Back to list

Contact us

For more information, do not hesitate to contact us