It’s easy enough to update a multi-dwelling unit (MDU
) with energy-saving automation if the devices require no new wires.
Now imagine if the devices required no batteries
either. The maintenance staff would never have to touch a sensor or hotel card reader again.
That’s what Leviton offers with its LevNet
line of wireless self-powered solutions.
Based on technology from Enocean
, the LevNet RF products require so little energy that they can be powered by the kinetic energy of a rocker switch a-rockin'
These little gems harvest energy from the mere press of button.
Even button-less LevNet products have ways of harnessing energy without the use of batteries.
Occupancy sensors, for example, are powered by the slightest changes in energy states, for example, the rise and fall of the temperature or ambient light.
And hotel key card holders save up energy every time a card is inserted or removed.
“Compared to other wireless protocols, these have a battery-free, kinetic-powered design,” says Ian Hendler, Leviton director of business development. “You don’t have to run any power.”
The magic is not just in the energy-harvesting technology but in the structure of the RF communications.
Very Lower Power Requirements
Two-way mesh-networking solutions such as Z-Wave (which Leviton supports in different lines) and ZigBee may be lightweight compared to WiFi, for example, but they require too much energy to operate without wires or batteries.
The same is true for standard security sensors which are always listening for activity on the network.
On the other hand, LevNet switches and other devices are not constantly at the ready, waiting for instructions from a sensor or controller.
Hendler offers a typical scenario for a hotel room, bathroom or other space:
When a user enters the room, he hits the light switch, generating the energy to power the radio transmitter. At the same time, the change in luminance energizes the in-room occupancy sensor. After a set amount of non-activity, the sensor signals a LevNet-enabled wired
RF light switch to turn off, and the cycle begins again.
This type of scenario is often combined with “bi-level switching” to maximize energy savings in commercial installs, according to Hendler.
With two lighting controls in a single-gang device, bi-level switches (shown above) "save additional energy by requiring a user to manually turn on an additional secondary load if required," he says. "The system automatically shuts off both loads when vacancy is detected."
In addition to the occupancy sensors, wireless light sensors are available, powering themselves with built-in solar cells that draw on available ambient light. They can operate for up to 48 hours in total darkness.
Other products in the LevNet line include thermostats, handheld controllers and the latest introduction: motorized shade controllers. A new adapter turns Somfy RTS-enabled wireless controllers into LevNet (Enocean)-compatible devices.
Perfect for MDUs
Hendler explains that the complete line is ideal for MDUs, including hotels and dorm rooms, where residents tend not to care about energy usage.
Most notably, the European-style card holders in the LevNet line make perfect sense for these venues. Typically, there is not an existing power source where these devices might be mounted. Furthermore, swapping out batteries in potentially hundreds of living units would be untenable for the maintenance crew.
Typical LevNet scenario: wireless, kinetic-powered hotel key card sets lights and temperature to comfortable settings when the room is occupied, and energy-saving levels when unoccupied.
Here's how Leviton describes its LevNet-enabled Hotel Key Card Holder (WSS0S-H0W):
The Wireless Self-Powered Hotel Key Card Holder is designed to create energy saving solutions for the hospitality industry. Energy is saved by ensuring that no devices are left ON when the room is not in use. Inserting a Key Card provides the energy to transmit an RF signal to LevNet RF Receivers that control lights or other devices in the room. When entering a room, a Key Card is inserted into the switch and an RF signal is sent to the Receivers that control the loads in the room. The individual Receivers then communicate with their corresponding loads to close the circuit. When the user exits the room and removes the Key Card from the switch, another RF signal is sent to the Receivers to open the circuits. Receivers then disconnect power to the devices.
Leviton's LevNet product line includes:
Wireless Occupancy Sensors (WSCXX-I0W)
Wireless Low Profile Occupancy Sensors (WSCXX-IRW)
LevNet RF Wall Switch Receivers (WSS10)
LevNet RF Remote Switches (WSS0S)
LevNet RF Line Voltage Relay Receivers (WSPXX and WSTXX)
LevNet RF Plug-In Receivers (WSG0S)
LevNet RF Low Voltage Receivers (WS0RC, WSPAS)
LevNet RF Thermostat (WS0TH)
LevNet RF Switch Leg Transmitters (WSSLT and WSTLT)
LevNet RF Dimmer Modules (WSDXX)
LevNet RF Light Sensor (WSCPC)
LevNet RF Accessories
Wireless Sensing Solutions
LevNet RF Single and Dual Rocker Switches
LevNet RF 3 x 3 Single and Dual Switches
LevNet RF Handheld 4-Button Remote
LevNet RF Hotel Key Card Switch
LevNet RF 3-Wire Relay Receiver (WSP05, WST05))
LevNet RF 5-Wire Relay Receiver (WSP12, WST12, WSP02, WST02)
LevNet RF Plug-In Receivers
LevNet RF Channel Room Controllers (WS0RC)
LevNet RF Shade Controllers (WS0RC)
LevNet RF 4-8 Channel Relay Receivers
LevNet RF Switch Leg Transmitter (WSSLT, WSTLT)
LevNet RF 0-10V Dimmer Module (WSD01)
LevNet RF LED Dimmer Module (WSD02)
LevNet RF Light Sensor (WSCPC)
LevNet RF RS-232 Serial Box Data Interface
LevNet RF Signal Strength Meter