Founten provides its hotel customers with the unique capability of capturing the actual energy savings being achieved in hotel rooms using the Founten Energy Management System. For the first time, the estimated savings that were used to justify the initial purchase and installation of an energy management system can be verified with detailed reporting. This savings information can be easily accessed and evaluated directly through the Usage Graphs provided in the Founten Site Manager. The following graph is from an actual hotel installation site:
The top graph shows the actual cost of energy consumed in the hotel on a day by day basis for one month. The colors allow viewing by floor. The user can also narrow the selection to individual rooms or groups of rooms. The bottom graph shows the savings being achieved for each of these locations.
How Savings are Measured
The Founten Site Manager keeps detailed records of all aspects of climate management within each hotel room. A key feature of the Founten system is the ability to automatically switch the climate settings of a hotel room to a low energy “Economy Setting” when guests check out. Therefore savings are the difference between the energy that would have been consumed had the thermostat been left at the setting the guest had been using and the energy consumed at the economy setting:
Savings = (GuestRateOfConsumption – EconomyRateOfConsumption) * RoomVacanyTime
The Room Vacancy Time is tracked by the Founten Site Manager using real-time information coming directly from the on-site Property Management System. The Economy Rate of Consumption is captured in real-time directly from the actual statistics being collected in each room. The Guest Rate of Consumption is derived as described in the following section.
Measuring Guest Rate of Consumption
Guest Rate of Consumption is the energy that would have been consumed had the thermostat been left at the guest setting. The Founten Site Manager automatically captures the thermostat setting at the time each guest checks out of their room. The following graph shows an actual hotel room for which savings were determined:
Across the top of the graph, a label shows when the room was vacant. The dark blue line shows the actual temperature of the room throughout the day. The horizontal blue line shows the cool setting and the horizontal red line shows the heat setting. The light blue vertical bars show the times when the HVAC unit was cooling the room to maintain the thermostat setting. As can be seen in the graph, the guest who occupied the room had the thermostat set to 68 degrees during their stay and checked out of the hotel at 12:42PM. The Founten Site Manager turned the HVAC unit off during the vacant time. Then at 9:51PM a guest checked into the room. The Founten Site Manager immediately set the thermostat to maintain Cool of 72 degrees and Heat of 68 degrees.
In this example the savings are based on what would have happened had the thermostat been left at the 68 degree setting during the 9 hours and 9 minutes of vacant time.
Fortunately we have accurate, real time information to determine this data. Because this hotel has several hundred rooms which are all the same size and have exactly the same square footage, even though the room shown above did not operate its HVAC unit, there were many other rooms in the hotel which were occupied and using HVAC during this rooms vacancy time. To measure the usage, the Founten system searches its database to find all of the other rooms in the hotel which had their thermostats set to 68 degrees during the vacancy time. It then finds the average energy consumption of all of these rooms during the vacancy time to establish a benchmark. Since there are a few differences in operations between rooms due to the actual performance level of each HVAC unit, its window exposure, and differences in room insulation, the system also calculates a “Performance Rating” for each room. Finally, the Performance Rating of the vacant room is compared with the benchmark rooms and the average energy consumption is adjusted to provide a room specific energy savings result. In the example above, $3.41 of energy was consumed during the times the room was occupied and $1.89 was saved by not using the HVAC during the vacant hours. This resulted in a 35% energy savings on a day when the only savings was during the daytime between guests.
Conclusion
Founten provides customers with a powerful reporting tool that shows energy savings being achieved by the Founten Energy Management System. This capability allows customers to maximize energy savings without impacting guest satisfaction. It also allows customers to confirm that the Founten System is delivering both the Return On Investment and ongoing savings that were envisioned when the system was installed.