E.M.S. Energy Management System) – Definitely one of those buzz words everyone now a days is talking about; the entire evaluation process certainly can be daunting once a building owner decides to start researching the technology. As I recently found out while researching for EcoGreenHotel, this is not an easy task! PIRs, Infrared, Wired/Wireless Systems, open protocol communication, closed protocol, upgradability, expandability, server based network vs. online cloud access – the list of comparable features goes on and on…
The snippet of the matrix I created to compare and rank features elucidates this point quite nicely! So with that in mindif you read no further, please take away that such variety and complexity means everyone’s physical building configuration and personal financial situation will dictate what EMS is right for you!
There are tens, if not hundreds of Energy Management Systems (EMS) out on the market today. Some market specifically to the hospitality sector; others present themselves as being able to deliver in any setting. Each manufacturer has its own “unique feature” to be sure – reading each firm’s brochures certainly can leave the typical property owner’s head spinning. With each claiming their ‘wheel is more round,’ ‘their method more accurate,’ and ‘their customers the most satisfied,’ the only definitive conclusion one can draw is either “they are all full of it”, or “I cannot believe how far behind the curve I am, given all these companies operating out here in this sector!”
The truth, as it always seems, falls somewhere in between. While certainly some manufacturers all offer slightly different system configurations, there is in my opinion pretty much an established EMS construction that is followed:
- An intelligent HVAC interface communicator – This essentially is the EMS’ brain where all the processing is performed in order to determine when to turn the user’s HVAC setting on and off.
- In-Room Sensors – These peripheral devices usually are installed thorough an area the HVAC system in question being controlled. These sensors can vary in function, but their essential function always remains the same – To determine if the HVAC should be running or not. Occupancy Sensors, Door Switches, CO2 Sensors, and/or Window Switches all can play a role with the room’s thermostat!
- Digital Wall Thermostat – Some system may require their own digital thermostat to act as the room’s HVAC controller, bypassing any on-unit controls or replacing the existing T-stat.
EMS 1.0 – First Gen Headaches
Many early adopters recall many headaches, late nights, and comp’d rooms from guest complaints. Chiefly, the issue was distilled down to guests complaining that the HVAC system simply did not behave the way they wanted it to… Equipment turning off in the middle of the night, set temperature fluctuations, and poor occupant detection – the primary source of these issues was the in-room motion sensor was not picking up the guest’s presence, thereby placing the room into an energy savings state.
Enter the door sensor. The addition of this component has dramatically reversed these issues by assisting the EMS system in finer-tuned occupant detection. With the DS component included in each room, the EMS can now more accurately determine when to “check for guest” and when to “stay out of the way.” Today’s SOP – upon a door event, the EMS wakes up and ping the PIR to begin scanning the room for a set amount of time. Once it detects an occupant, it disables the energy savings HVAC settings and allows the HVAC to behave as if the EMS has not been installed. Should the door open, the system repeats the process.
This programmed behavior is the gold standard balancing energy savings and guest comfort.
Effective EMS = Realistic Programming
Beyond the hardware and technical mumbo-jumbo, a quick diversion into what makes an effective EMS function is simply smart programing! Careful forethought into what the space’s needs are, typical occupant behavior, and the space’s physical location concerning sunlight, and building envelope penetrations all should be taken into account ahead of any EMS installation. Extremely aggressive temperature setbacks during unoccupied periods can lead to guest complaints. Telkonet is one manufacturer who touts its ability to “recover” a room from an unoccupied to occupied temperature setting last selected in the room prior to being vacated. This manufacturer places emphasis on this ‘remembering feature,’ which a lot of other competitors simply do not offer. Instead, upon reentering, the guest must reinitiate the space conditioning at the thermostat and even re-set the desired temperature.
Other manufacturers tout “invisibility to the guest” – translation: less aggressive, more simplistic temperature setbacks and more basic system configurations. It is important to note that simplistic systems do not necessarily mean poorer EMS performance. Again, the system’s configuration settings will be the driving factor dictating user comfort vs. energy savings. In fact, “simpler” system architecture can have its own set of benefits; flexibility and compatibility are the primary benefits. Have a system with multiple HVAC equipment manufacturers and configurations, some with T-stats, and some with on-board controls? A system like Lodging Technologies’ GEM system has a leg up on the competition when it comes to interfacing with the multitudes of HVAC equipment properly. LT’s GEM only “exposes” the guest to seeing its PIR and door sensors; there is no proprietary thermostat available, relying on your existing temperature control interface. GEM is stand-alone, meaning it is non-networked and does not require, nor is it able to communicate into a back-of-house terminal to show a room’s occupancy or equipment status.
The other extreme to a flexible system like GEM is Amana’s proprietary DigiSmart system. Compatible only with Amana PTACs, DigiSmart is analogous to Apple’s product ecosystem where only certain devices “play nice” with one another. Amana’s DigiSmart is simply another “accessory” one might add-on to an HVAC equipment order, creating a simple ordering process. The downside is this accessory will only work with the Amana equipment you have purchased. If you decide down the road to switch HVAC manufacturers, this $200 accessory suddenly becomes a $200 paperweight! Additionally, DigiSmart does not come with a installer; it is up to the site to either install it on their own or locate a suitable installer. Personally, despite these downfalls we have seen very positive results from the DigiSmart system and installation is not too difficult if you have a staff member that is familiar with electronics and PTAC equipment. Amana’s cloud-based architecture allows the EMS to be networked and report in to an internet site where one can simply log-in and view the EMS status and estimated savings.
Dollars and Cents
A discussion about Energy Management Systems cannot be completewithout touching upon the rebates and incentives that are available to the hospitality industry. Many local utilities and state energy efficiency programs have recognized energy management systems in hotel guest rooms as a specific energy savings measure eligible for some assistance to implement. It is important to check with your local utility and state’s department of energy or environmental protection to see what rebates you may be eligible for. Based on our experience assisting clients, we have seen new construction in Michigan receive $25/room for a prescriptive (pre-determined) incentive for an EMS controlling electric heat HVAC equipment to $0.05/kWh saved in Pennsylvania for a custom incentive. This quick example shows the variability among different programs. Navigating a rebate programs’ applications and technical analyses requirements can certainly be frustratingly difficult and convolutedly complex, but definitely ARE WORTH YOUR TIME! Making friends with a specific rebate administrator program representative is the easiest path to incentive award dollars; and as always, you can engage EcoGreenHotel to spearhead this rebate administration process.
Don’t know where to start? … Visit EcoGreenHotel’s Rebates & Incentives page to find a clearly spelled out list.
To Infinity And Beyond!…
The sky is certainly the limit when it comes to features offered by some EMS systems. Most EMS systems that are not “stand-alone,” or non-networked, offer the capability to interface with a hotel’s Property Management System (PMS) at the front desk in order to sync rented and unrented rooms. This exchange allows the EMS, if setup the way EcoGreenHotel advises, to know which rooms should be taken off more aggressive temperature setbacks and immediately placed into a less obtrusive temperature delta scheme.
From scheduling spa services to lighting level control, if there is a feature desired for a guest’s in-room control there is an Energy Management System out there that can do it! For example, Honeywell’s InnCom system can interface with Housekeeping to be notified when a guest would like maid service; likewise, notification of valet and room service tray pickup are also feasible. Want all this on an iPad® app for your guests to use? With InnCom, there’s an app for that! Evolve’s Networked system offers premium features a table top controller capable of scheduling golf course tee-times, the guest room’s curtain position, TV, and of course the heating & air-conditioning.
For more information on energy efficient technologies or if you are looking for support in your sustainability efforts please contact me at firstname.lastname@example.org or 888.229.0213.
About the Author
Geoffrey Grochmal graduated from George Washington University with a BA in Economics and since early 2011 has developed energy solutions, specializing in Energy Star benchmarking and Energy Modeling. Previously, Geoff had conducted an extensive array of quantitative research, focusing on California “green” legislation, AB 939 Integrated Waste Management Act: findings showcased a fundamental link between an area’s wealth and its ability to meet the state’s “green goals., “Today, Geoff brings proven sustainability technologies to EcoGreenHotel’s clients pairing solutions with ROI’s to meet the ever changing economic landscapes of our clients.