HVAC Shutoff
for Open Doors/Windows


  • Description
  • Features
  • Licensing
  • PTAC
  • Central A/C
  • RF Option
  • Wiring
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  • HVAC Smart Relay Switch

    Energy-saving device for heating & AC

    Automatically shut off air conditioning or heating when a monitored door or window remains open!
    * offer ends 5/31/16

      Buy today and your order will include two door/window sensors.

     Plus, use promo code FREE-SHIP05 and get free shipping (continental U.S. only).

    Click here for more information about this limited-time offer.

    * offer ends 5/31/16
    Click here

    HVAC Smart Relay Switch
    (Sensor shown above is included when purchasing the wireless combo system. Otherwise, a standard wired sensor is provided.)

    Reduce energy consumption in schools, hospitals, hotel rooms,
    apartments, condominiums, rental properties, and more!


    In an era of high fuel costs, the HVAC Smart Relay Switch (HSRS) lowers energy bills by eliminating wasted power consumption. The HSRS eliminates waste by monitoring open doors and windows. Accepting wired and/or wireless sensor inputs, the HSRS automatically interrupts the HVAC system in the event of a violation such as a door or window that has remained open for a period of time or a room that has been vacant. The HSRS is a fully configurable device that provides energy efficient control for heating and cooling systems. In addition, the HSRS can be used as a general purpose controller for devices including dampers, fans, etc. The HSRS accepts one or more contact switch closures as control inputs. Compatible with door/window reed switches, motion sensors, toggles, pushbuttons, etc., the HSRS can accept any switch or sensor device having normally open or normally closed contacts. The HSRS is fully configurable using onboard DIP switches, allowing you to establish specific operational parameters. For instance, configure the device to temporarily disable the air conditioning or heating system when any door or window has remained open for 10 minutes and then re-enable when the door has closed. Onboard DIP switches allow you to configure operational mode and delay parameters. 

    The HSRS provides connections for as many as 4 wired inputs or zones. Each input can accept a single switch sensor or multiple sensors if wired in a zone configuration (sensors are wired in series or parallel). Typical switch sensors include reed switches, pushbuttons, toggle switches, or other devices. (Note that the HSRS can be configured to accept either normally-open or normally-closed switches.) Wired inputs are also compatible with TTL signals. (Note: Wired sensor cabling should be limited to 100 ft. max. at each input. Twisted-pair shielded cables recommended.) 

    And, with an optional RF receiver, the HSRS also accepts input from compatible wireless door/window sensors, motion detectors, and key fob transmitters. The wireless option provides inputs for up to 8 additional devices. Even deploy a combination of both wired and wireless sensors.

    The HSRS is the ideal energy management solution, reducing power consumption and energy costs. Simply install door / window sensors and configure the controller with easy DIP switch settings. 

    is ideal for a number of venues including:

    • Hotels (also see hotel energy management solutions)
    • Hospitals
    • Condominiums
    • Office buildings
    • Industrial complexes
    • Apartments
    • Rental properties
    • Schools & Universities
    • and more!

     HVAC Smart Relay Switch
    The HSRS is also available with wired sensors!


    Shuts off air conditioning or heating when a violation is detected
    Compatible with existing central air conditioning & heat pump systems
    Works with existing HVAC equipment; requires no thermostat modifications
    Can also be used with PTACs, window fans, dampers, etc. (see note below)
    Fully programmable via DIP switch settings
    Configurable parameters including trigger polarity, LED mode, buzzer enable, etc.
    Optional shutoff delay ranging from 1 sec. to 10 hours
    Five status LEDs:  system status plus switch sensor indicators
    Onboard relay: 10A @ 250VAC,  5A @ 100VDC
    Accepts wired inputs for monitoring up to 4 wired zones
    Optional RF receiver add-on for 8 wireless zones
    Configurable re-activate (relay on) and de-activate (relay off) delay periods
    Optional wireless RF receiver for 8 wireless sensors, motion sensors, or fobs
    Available modes for occupancy / vacancy detection (requires motion sensors)
    DB9 interface for wireless RF receiver (for use with optional wireless sensors)
    DIP switches for mode selection & configuring operational parameters
    Selectable re-activate / de-activate time delays
    Terminal block connector for user wiring
    Powered by external 12VDC adapter (optional 24VAC adapter also available)
    Optional external power converter module accepts 24VAC for use with HVAC systems
    Can be customized to suit your specific requirements


    Note: PTACs, window units, and mini-split systems do not typically provide a means for external control by third party devices such as the HSRS. Please consult your HVAC contractor or technician to determine if external control is possible for your particular system. 

    Have Questions?

    We've got answers - visit our Frequently Asked Questions page!

    - Decals -

    Do you own or manage guest lodging such as a hotel or vacation rental? Need to remind patrons to conserve energy? Measuring approximately 3" x 4", these adhesive-backed gems make great reminders. If you would like to have them included with your order, just let us know. We'll be happy to provide them free of charge.
    Get yours today while they last!
    (Limit 2 per order. Larger quantities available upon request and may incur a fee.)

    Design Licensing

    This item is available for licensing to OEMs. This design is available for OEM licensing. Licensing allows your company to manufacture this item and gives you royalty-free sales and distribution rights.  Click here for additional details.

    Application #1:  General Purpose (A/C, heater, damper, etc.)

    PTAC application

    Application #2:  Central A/C System (complete shutoff)
    (click here to enlarge)

    Central A/C

    Wireless RF Option

    For installations where traditional wire runs are not possible or may be inconvenient, we offer a wireless option that consists of sensor devices and RF receiver.
    Other compatible peripherals include motion detectors, key fob remote transmitters, etc. Door/window sensors are shown below: 
    Wireless door/window sensor
    Wireless door/window sensor
    Wireless door/window sensors

    The RF receiver includes antenna and compatible connector interface for direct connection to the HSRS controller. There are two available receiver models, shown below:  

    RF Receiver

    Antenna w/           
    coax cable            

    Type-A receiver is the first generation model. Type-B is an upgrade that features LED indicator and enhanced reception. Both models receive signals from compatible door/window sensors. The image below shows the items included in the wireless combo package.

    1. HSRS controller
    2. Receiver power cable
    3. Wireless receiver
    4. Door/window transmitter
    5. 110 VAC converter
    6. Whip antenna
    7. Receiver interface cable
    8. 24 VAC converter
    9. Antenna cable
    HSRS controller Notes:
    1. The power converter provides proper voltage to the HSRS controller. Only one of the two converters shown in the picture above will be needed in any given application.
    2. There are two possible receiver models as previously described. Type-B is shown in the picture.
    3. The receiver interface cable connects the wireless receiver to the HSRS controller. This cable is required for the type-B receiver but is optional for type-A. (The type-A receiver can be plugged directly into the HSRS controller.)

    HSRS Wiring Installation

    The HSRS is ideally suited for use with split (central) systems. We recommend mounting the HSRS controller near the air handler and routing a length of low-voltage wire into the unit for direct access to the 24vac transformer. (Most any low voltage wire will suffice such as telephone, intercom, or alarm wire - two- or four-conductors preferred.) This wire is needed for two primary purposes: 1) for powering the HSRS controller and 2) for interrupting the HVAC's 24vac supply when a door/window violation occurs.

    The following instructions demonstrate a typical wiring installation. (The following items will be needed: screwdriver, wire cutter / stripper, splicing connectors and several feet or more of low-voltage wiring.)

    Caution: Although HSRS wiring is not complicated, only a qualified HVAC contractor, technician or electrician should attempt the procedure. These instructions are provided for demonstration purposes only. The installer assumes full responsibility for a proper install and to verify all wiring modifications. While these instructions are believed to be accurate, we accept no liability or responsibility for possible errors or omissions. Should you encounter any issues during an install, contact us for free on-site phone support.

    • Shut off power to the a/c system.
    • Detach HSRS enclosure lid by removing retaining screws.
    • Remove front cover from the HVAC air handler unit.
    • Locate low voltage (24v) wires from transformer.
    • Cut and strip two wire segments of desired length.
    • Using splicing connectors, join each segment in parallel with existing 24v output wires from the transformer.
    • Connect remaining ends of the spliced wire segments into HSRS power converter terminals (white terminal block).
    • Cut one of the existing 24v transformer wires, creating two loose wire ends. (Note: Be sure to cut the wire downstream of (past) the spliced connection you made in the previous step.  Cutting the wire upstream of the connection will inadvertently shut off the HSRS controller along with the a/c system when a door/window violation occurs.)
    • Strip the two loose wire ends. (If desired extend the loose ends using additional wire segments and splicing connectors.)
    • Connect one wire end to HSRS terminal 12.
    • Connect the remaining wire end to terminal 13.
    • Replace air handler front cover.
    • Replace HSRS cover.
    • Restore a/c system power.

    A convenient termainal block is provided for wiring purposes. The table below lists the terminal connections:

    Terminal Description
    1 Input power (+12VDC)
    2 Ground
    No connection
    4 Wired sensor #1
    5 Wired sensor #2
    6 Wired sensor #3
    7 Wired sensor #4
    8 Sensor return
    9 Sensor return
    10 Sensor return
    11 Sensor return
    12 Relay - COM
    13 Relay - N/C
    14 Relay - N/O


    HSRS Brochure
    (free PDF download)


    Comments / Feedback

    As property manager of ocean-front vacation condominiums, we have had ongoing problems with guests who leave patio doors open so they can enjoy the view. This has resulted in enormous electric bills, especially in summer months when the air conditioning has run continually. We purchased and installed the HSRS in June, 2011 and were pleased to discover an immediate savings in our electric bills. The system has been extremely reliable with no false detections. In fact, one day a guest called to report that his air conditioning had stopped working.  When asked if any exterior doors were currently open, he replied, "yes". After closing the door, the HSRS re-activated the a/c and resumed normal operation. I'd recommend the system to anyone looking to save money on their heating and cooling costs.
    Sam M., Hatteras, North Carolina

    For more comments, click here.

    FAQ / Contacts

    Got Questions? We've got answers.
    Use one of our convenient methods below for more information:
    Frequently Asked Questions
    ph: 321-757-9280


    The HSRS is our flagship HVAC shutoff system and is available in both wired and wireless varieties.

    HSRS Pricing

    $399 Buy Now

    An economical alternative to the HSRS is our general purpose Quad Relay Delay Switch (QRDS-1000). The QRDS-1000 is a general-purpose relay device that can be used in any number of applications. Though less robust than the HSRS, the QRDS-1000 is also easily suited for HVAC shutoff control. (We offer a free DIY tutorial in PDF format describing how to use the QRDS-1000 for HVAC shutoff.) For additional details, click here:

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