The Vent-Axia NBR DMEVe is a range of continuous extract fans designed for kitchens, utility rooms, bathrooms, and toilets. Available in 100mm and 125mm sizes, these fans incorporate an airflow detection system that senses installation duct resistance and adjusts fan speed to maintain a preset extract flow rate. The fan's configuration can be customized by the installer using an integrated LED display.
Technical Specifications:
- Voltage: 220-240V~50Hz
- Protection: IPX5
- Insulation: Class II double insulated (must NOT be earthed)
- Cross-sectional area of supply cord: 0.75 - 1.5mm²
- Operating Temperature Range: -5°C to 40°C
- Max. Flow Rate (100mm models): 50.04 m³/h
- Max. Power Input (100mm models): 1.50 W
- LWA: Sound Power Level (100mm models): 39.52 dB
- Ref. Flow Rate (100mm models): 0.01 m³/s
- SPI (100mm models): 0.03 W/(m³/h)
- Annual Electricity Consumption (100mm models): 0.17 kWh/a (HT models), 0.36 kWh/a (standard models)
- Max. Flow Rate (125mm models): 135 m³/h
- Max. Power Input (125mm models): 10 W
- LWA: Sound Power Level (125mm models): 54.5 dB
- Ref. Flow Rate (125mm models): 0.026 m³/s
- SPI (125mm models): 0.03 W/(m³/h)
- Annual Electricity Consumption (125mm models): 0.17 kWh/a (HT models), 0.36 kWh/a (standard models)
- Control Factor: 0.65 (HT models), 0.95 (standard models)
- Control Typology: Local Demand Control (HT models), Clock Control (standard models)
Installation and Wiring:
Installation must comply with current I.E.E. Regulations or appropriate national standards and be performed by a qualified person. The fan is suitable for installation in Zones 1 & 2. A local isolator switch capable of disconnecting all poles with at least 3mm contact separation must be provided. Ensure the mains supply matches the rating label. The fan should only be used with appropriate Vent-Axia products and fixed wiring.
The fan can be mounted on a panel, ceiling, interior wall, or exterior wall. For panel/ceiling/interior wall mounting, a 107mm (100mm fans) or 130mm (125mm fans) diameter hole is required. For exterior wall mounting, a 117mm (100mm fans) or 140mm (125mm fans) diameter hole is needed, with the wall sleeve sloped slightly downwards away from the fan. A built-in spirit level bubble aids in marking screw centers for mounting.
Wiring diagrams are provided for continuous trickle (Fig. 1), continuous boost with no trickle (Fig. 2), and continuous trickle with boost (Fig. 3). All connections must be secure. The impeller should rotate freely after installation.
Usage Features:
The NBR DMEVe offers various configurable settings accessible via an LED display and control buttons (Up, Down, Mode/Set) located behind the inner grille. The fan must remain powered during configuration.
- Display Modes: Upon power-on, an initialization sequence runs. Pressing a button activates the menu system. If inactive for 30 seconds, a button press is needed to reactivate the menu. The initial button press to activate the menu does not change settings.
- Prism Mode: When activated, the display mirrors characters for correct viewing through the fan cover's prism. This mode runs for 15 minutes, cycling between displaying airflow rate, estimated duct pressure (if CV/F-2 mode enabled), and current RH% (HT models only).
- Standard Settings:
- Rotate display (r-Y/r-n): Toggles display orientation.
- Trickle speed adjustment (Erl): Sets continuous extract flow rate (6-8 l/s for 100mm, 9-10 l/s for 125mm). If "0" is selected, the fan operates in Intermittent mode.
- Boost speed adjustment (656): Sets higher extract flow rate (13-14 l/s for 100mm, 13-15 l/s for 125mm).
- Boost Overrun time (615): Adjustable from 0 to 30 minutes (0 disables overrun). Default is 15 minutes.
- Humidity level trigger (670): Sets the relative humidity threshold from 40% to 90% for boost activation. Default is 70% RH.
- Fan Control Mode (F-0/F-1/F-2):
- F-0: CV disabled, wall/window installation (factory preset speeds).
- F-1: CV disabled, ducted installation (factory preset speeds).
- F-2: CV Constant Volume enabled (fan automatically adjusts speed to maintain desired airflow after a 15-minute calibration period).
- Comfort mode (c-n/c-Y):
- c-n (normal LS overrun): Fan boosts immediately on Light Switch (LS) input and overruns for the set period after LS disconnects.
- c-Y (comfort mode): Fan remains off/in trickle for up to 20 minutes after LS input. After LS deactivation, the fan runs in boost mode for the duration LS was active (up to 20 minutes) plus the overrun time. No boost occurs if LS was active for less than 3 minutes.
- Advanced Settings:
- RH Ambient Response (A-Y/A-n): Enables/disables ambient humidity response. When enabled, the fan slowly increases speed between trickle and boost speeds as humidity rises between the trigger %rH and +10%. The trigger point adjusts if the temperature drops below 18°C to prevent nuisance triggering.
- RH Rapid Response enable (p-Y/p-n): Enables/disables rapid rise humidity detection. If a rapid rise in humidity is detected while ambient %rH is below the threshold, the fan increases speed proportionally between trickle and boost until humidity lowers.
Maintenance Features:
The fan has sealed-for-life bearings, requiring no lubrication. Regular inspection and cleaning are necessary to prevent dirt build-up. Inlets and the front face should be wiped with a damp cloth. Care must be taken not to push dirt into the airflow sensor.
Calibration:
The airflow sensor is factory-calibrated using UKAS accredited equipment. In some cases, calibration settings may need to be reset (e.g., if the fan was covered). To reset, configure the fan to wall or duct mode (F-0 or F-1), power cycle the product, then re-configure back to CV mode (F-2). The fan will recalibrate after 15 minutes.
Troubleshooting:
- Fan speeding up and down: Normal in windy conditions to maintain airflow. If continuous nuisance, change fan setting from F-2 to F-1 or F-0.
- Fan moving too much or too little air: Update speeds if set incorrectly. If due to windy conditions during initial power-on, reset the fan by updating F-2 to F-0, power cycling, then back to F-2. If reacting to external airflow measurement devices, the fan will revert to original speed after a few minutes.
- Fan displays ERR during calibration: Due to windy conditions during initial power-on. Power cycle the fan when external wind conditions improve, and the fan will retry. The fan will still function normally and attempt to match the target flow rate.
Safety Notes:
- Do NOT install in areas with excessive oil/grease, corrosive/flammable gases/liquids/vapours, or ambient temperatures outside -5°C to 40°C.
- Avoid obstructions that hinder access or removal of the fan.
- Do NOT use where liable to direct water spray for prolonged periods.
- When removing air from a room with a fuel-burning appliance, ensure adequate air replacement.
- For moisture-laden air, fit a condensation trap and slope horizontal ducts slightly downwards away from the fan.
- This appliance is not intended for use by persons (including children) with reduced physical, sensory or mental capabilities, or lack of experience/knowledge, unless supervised or instructed by a responsible person.
- Young children must be supervised to prevent them from playing with the appliance.
- Do NOT attempt to remove the circuit board cover, as it contains high voltage power supply.
- The fan and ancillary control equipment MUST be isolated from the power supply during installation or maintenance.
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