Project data
Authors Matthew Urquhart
Status Verified
Verified by Queen's University Green IT Group
Uses saving energy
Instance of Green IT
Download Open Know How Manifest
Page data
Part of MECH425 Engineering for Sustainable Development
Mech425 GreenIT Project
Queens Green IT ECMs
Type Project
Keywords energy saving, Energy conservation measures, Energy audit, Energy efficiency, Finance, vending machine, motion sensors, Engineering
SDG Sustainable Development Goals SDG07 Affordable and clean energy
Authors Matthew Urquhart
Published 2010
License CC-BY-SA-4.0
Affiliations Queen's University
Impact Number of views to this page. Views by admins and bots are not counted. Multiple views during the same session are counted as one. 712
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Vending machines are an everpresent novelty in many establishments and a simple example of how energy saving techniques can be applied with significant impact to energy costs and annual CO2 output. Here we explore the economic and environmental viability of using a motion sensor unit to control the operation of a vending machine such that it remains on stand-by mode while not in use. When motion is sensed (that is, a potential customer approaches the vending machine), the controller turns on the machine's light and compressor to be ready for a sale. The lights and compressor (optional) are then then turned off after a predefined period of inactivity, typically 15 minutes. Quality of vendable goods it maintained by a microcontroller in the system that powers up the machine every 2 hours to to maintain standard operating temperatures. This calculator tool allows you to input your particular operating conditions and explore the affect this type of system would have on your organization.

ECM Inputs[edit | edit source]

The following inputs are used in this calculator. For some, default values are provided that can be considered appropriate for many scenarios. The remaining inputs are more specific to the particular instance. For more information, consult the particular calculator and its Assumptions & References section.

  • Number of vending machines
  • Cost of electricity and maintenance labour
  • Usage terms such as power consumption and "up-time" of the machine
  • Sensor cost and effectiveness.

ECM Assumptions[edit | edit source]

Several of the default values for the input factors have been taken or estimated from data in the Assumptions & References section. Please consult the individual assumptions for more information.

Download this calculator[edit | edit source]

The most recent version of this calculator, as confirmed by the Queen's Green IT Group (original constructors of the document), is available here:

See also[edit | edit source]

For more information, check the Queen's Green IT ECM homepage.

References[edit | edit source]