If you’ve ever stayed at a hotel where a motion sensor controlled the thermostat, you know the unpleasant feeling of walking into a hot room when all you want to do is sit down and relax after a long day. If you’re like me, you’d think the reason for these devices besides making our lives miserable is to save the hotel money. If they don’t have to run the air conditioning unit to cool the room all day, that reduces the electric cost and increases the profit for the hotel.
Not so, says a blog post by Lodging Technology. Motion-sensing thermostats actually increase the room’s comfort by controlling humidity levels, so turning off the AC during the day is a good thing. Coming as no surprise to me, Lodging Technology is a company that manufacturers the thermostats, along with other technology products for hotels, so reading their spin about why these products are beneficial was eye-opening.
I actually came across this “blog post” when researching why some hotel rooms feel so humid. I found the beginning of the article informative when it came to explaining how humidity gets into hotel rooms and the damage having moisture buildup in rooms can have, such as mold issues and damp furniture.
The “dew point” is the temperature at which air can no longer hold all the moisture it contains in suspension. Some water vapor must come out of suspension and condense in the form of water droplets.
When guest room walls are allowed to chill below the dew point all day (when guests are out), moisture from inside and outside sources will condense on both sides of the wall covering, thus damaging dry-wall and encouraging the growth of mold and mildew. It also condenses and is absorbed by cool furniture and bedding surfaces and causes the room to feel cold and clammy, rather than cool and dry.
I was getting convinced by the science. Maybe these devices do help the rooms stay more comfortable.
Guest room occupancy sensing systems have a positive effect on humidity control.
A properly designed occupancy sensing system does not turn off the heat-ing/cooling unit in unoccupied rooms. It maintains the room at a slightly warmer, management-selected, energy-conserving temperature. The system prevents chilling of the room during the hot and humid midday when guests are typically out, thus reducing water vapor pressure, migration of moisture into the room and condensation.
Warmer air “holds” more moisture, re-moving water from furniture, fixtures and equipment (FF&E). Remember that air at 90°F holds twice the volume of water as air at 70°F does. Energy management systems (EMS) assist in the reduction of humidity problems. The key is to install a sensing system that includes a temperature setback feature and operates the air conditioner periodically to lower room temperature and remove large amounts of moisture from the warmer air. The room is again allowed to warm up and “pull” more moisture from furnishings. This cycle is repeated while guests are out of the room 60 percent of the day.
I’m not a fan of the idea of having the thermostat of my room set to a “slightly warmer, management selected, energy-conserving temperature” during the “60 percent of the day” I’m not in my room. How do they know when I’ll be returning to the room? What if I come back in the middle of the afternoon for a short nap right in the middle of one of these warming “cycles?” How long will it take for the room to cool off to a slightly cooler, guest-selected, energy-wasting temperature?
At least at home, I can set the thermostat to change temperature based on our lifestyle. I don’t have to cool the house to a setting for sleepytime until around 1 AM because we’re typically up until then.
At the end of the post, the writer dropped the charade, left the science behind, and just made the sales pitch. Hotels don’t care about comfortable rooms; they care about more money in their pockets.
Occupancy sensing systems will increase profits by reducing room HVAC energy consumption by 35 to 45 percent, while improving guest comfort and preserving guest room FF&E. Hoteliers will clear the air of unwanted moisture while taking profits to the bank.
Final Thoughts
There is actual science behind how water moisture can condense in hotel rooms, which makes the whole place feel damp. Most of those cases are from improperly designed or poorly-maintained systems. I can see the desire to find a solution to keep the room climate adequately balanced to prevent the buildup of mold and the drywall’s breakdown.
However, we’ve been shown what hotels will do once they have access to control your thermostat. Many of them set them to outright lie about the temperature and forbid you to set the room to a comfortable setting. If that’s the case, there are ways around that. It’s not so much the technology behind these devices that I have a problem with. It’s what hotels will do with that tech once these devices are installed.
These new systems have infrared scanners to sense body heat, so there’s no fooling it with things that give a sense of motion, like a balloon. The ability to centrally monitor a room’s occupancy status and adjust the temperature however they see fit seems like something hotels could totally take advantage of. What’s a reasonable temperature to set a room during a summer afternoon in Orlando? 80 degrees? 82? If so, don’t leave any chocolate out on the counter or even a medicine meant to be kept at “room temperature” because you have no idea what the hotel will set your room to while you’re gone.
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5 comments
Colder rooms are more humid? Sure, if you just recirculate the air through a cooler (or worse, through a swamp cooler that forces air over cold water to both cool and humidify it). AC-cooled rooms tend to be less, not more, humid than uncooled ones.
Within an AC, the air – including water vapor – passes over a REALLY cold evaporator, usually dropping below the dew point; the condensate drains or is pumped away, meaning what comes out has less water vapor than what came in. The typical “warmer=drier” scenario is when a room is actively being warmed, as the air is being recirculated without the addition of water.
A room cycling between warm and cold is actually worse than one at constant temperature, as solids take longer to change temperature than gases, so part of the time, you have cold objects surrounded by warm air (which at the same relative humidity as cold air has a lot more water). The air flowing over the cold surfaces cools, dropping below the dew point, and forming condensation on them.
TL;DR – temperature cycling is bad.
So we know the real reason is to save money and pseudoscience was used to hide that fact.
The biggest problem with most of these systems are at night. The systems usually have a night mode that is suppose to override the motion sensor and keep them from kicking off and making the room warm when it cannot sense your sleeping body movement (think Tom Cruise in the first Mission Impossible movie). Problem is that the hotel, company that installs them or the management either doesn’t know how to set this feature up properly or intentionally has it set to turn off. That’s why you wake up at 2am in a sweat in Miami to check the thermostat only to have it come on and cool it down for a few minutes only to have you wake at 4am with the same problem.
I agree. Many times I’ve woken in the middle of the night and had to wave my arms in the air to activate the motion sensor. It’s really irritating.
These smart thermostats are at the end of very dumb wiring. It’s comically easy to harmlessly bypass the thermostat. Basic HVAC wire colors can be verified by pulling that cover off the heating unit. Jump the wires or even install your own thermostat for the night. It’s what I do. Nothing sucks as much as setting the hotel thermostat and learning, about an hour after you lie down, that’s it’s lying to you.