Hotel room Energy Savings

There seems to be a lot of interest in saving energy in hotel rooms and timeshare resorts lately. After hearing what some of these places spend on electricity (hundreds of thousands of dollars per year) it's no wonder. I think there's a lot of energy to be saved there, given how often people leave the A/C running full blast even when they leave the room for the whole day.

Whether it's a standard window air conditioner like you'd pick up at Home Depot, or a PTAC (packaged terminal air conditioner, I think) unit, they use a lot of power. When running, they're probably 2 kW at a minimum, and if you're out of the hotel room most of the day, that's a lot of kWh. I understand that in Europe, a lot of hotels have occupancy (presence or absence) sensors in the rooms or "key card switches" at the entry of the rooms to enable the power in the room. It seems that there aren't any cost-effective technologies to detect the presence of a non-moving person in a room, so when people go to sleep at night an occupancy detector isn't an ideal solution.

The key card switch seems to be pretty popular, however. When you enter your hotel room, using a magnetic stripe key, there is a slot near the entry door to "store" the card. When you insert the card into the slot, a switch is activated to enable the power and A/C in the room. In a new hotel, it's pretty easy to wire for this, though the extra wiring may be expensive. In a retrofit, however, a wireless device like the illumra key card switch is really slick - just sitck it on the wall, and it sends radio messages to the receiver installed in the PTAC (at a minimum) and on the lights and television, too.

I've intentionally stayed away from discussing specific illumra products in this blog, rather focusing on energy savings, green solutions, and other general topics. I'll generally keep to this policy, only occasionally linking to illumra.com, because the energy problems we face are much bigger than any product or company can hope to fix on their own. (See the "full disclosure" in my first post - I work for a company making energy saving products, so I'm at least a little biased.) Everyone has something to contribute to the solution, and I expect to cover a lot of them. Even within the battery free wireless space there are a lot of players, and if you want to see some of them, take a look at the EnOcean Alliance for more information. There are a lot of very cool products out there, but a little due diligence is important before installing any new technology. Analysis, even a quick back-of-the-envelope calculation or even a very rough "guestimate" should be used to justify any energy saving measure.

As an example of this, one of the features some people have requested for hotel key card switch control is the use of a window sensor to disable the A/C when the window is open. This is nothing new, it's used in a few places in Europe I know of. However, the incremental cost of adding the window sensor may (or may not) result in a significant return on investment compared to just using the hotel key switch alone. After all, if only one or two windows are opened regularly in a 1000-room hotel, even if the A/C is running, the cost savings of having the A/C turn off automatically (when the window opens) may be pretty small. On the other hand, if you're in a tropical area near the beach and people open windows regularly, the cost of the extra sensor may be paid off very quickly.

In the end, a lot of little changes will add up to a big change over time. I've been more careful to shut down my computers or put them to sleep when not in use, and noticed a few dollars difference in my last electric bill. Not much, I admit, but maybe I can find a few more places in the house to use compact fluorescents. Once the dimmable ones aren't prohibitively expensive, I may be able to try them in a few more fixtures, too. I'm glad I live in a dry climate, as my evaporative air conditioner ("swamp cooler") is a lot less expensive to operate than central air would be.