Idle Curiosity About Measuring indoor humidity
January 10, 2011 10:31 AM Subscribe
I use this humidifier in my office. The office is approx. 8' x 10'. I have used four different hygrometers (humidity measure-ers) over the past 6 weeks or so, placed within 4-5 feet of the humidifier. Despite always having the humidifier on the highest setting, the hygrometers never measure higher than 16-19% relative humidity, which is quite low. Why don't the relative-humidity readings go up as the humidifier puts out moisture?
Other datapoints: Two of the hygrometers are digital, and two are analog. One of the digitals is this Western Digital one, which is very highly regarded for accuracy. All hygrometers have been calibrated with both the salt test and a Boveda 1-Step calibration kit. The humidifier puts out about 3/4 gallon of water during my 8-hour workday and sits about 2.5' from me on a desk. It does not leak, and the desk beneath it doesn't get wet or collect condensation. The water is definitely going in the air. So why won't this show on the hygrometer readings?
The relative humidity generally reads the same when I leave at night (16-19%) after a full day of using the humidifier, as it did when I first arrived that morning after the humidifier was off all night. I work in a research facility, so the building's indoor climate is diligently kept constant for the sake of the equipment. I'm mostly just asking out of curiousity: the humidifier does help keep me from getting itchy skin and nosebleeds (the reasons I brought it in), so I'm just befuddled why it doesn't seem to affect relative humidity readings.
Other datapoints: Two of the hygrometers are digital, and two are analog. One of the digitals is this Western Digital one, which is very highly regarded for accuracy. All hygrometers have been calibrated with both the salt test and a Boveda 1-Step calibration kit. The humidifier puts out about 3/4 gallon of water during my 8-hour workday and sits about 2.5' from me on a desk. It does not leak, and the desk beneath it doesn't get wet or collect condensation. The water is definitely going in the air. So why won't this show on the hygrometer readings?
The relative humidity generally reads the same when I leave at night (16-19%) after a full day of using the humidifier, as it did when I first arrived that morning after the humidifier was off all night. I work in a research facility, so the building's indoor climate is diligently kept constant for the sake of the equipment. I'm mostly just asking out of curiousity: the humidifier does help keep me from getting itchy skin and nosebleeds (the reasons I brought it in), so I'm just befuddled why it doesn't seem to affect relative humidity readings.
In a facility such as yours, the air is probably turned over quite frequently, making it tough to actually change the humidity significantly. If you have an air return in your office, you could try blocking it for a short time to see if it changes the humidity, but the facilities people are likely to be upset, so I wouldn't recommend it.
posted by JMOZ at 10:46 AM on January 10, 2011 [4 favorites]
posted by JMOZ at 10:46 AM on January 10, 2011 [4 favorites]
Yeah, assuming you've got a typical hvac system, the output of your little humidifier is being spread throughout the whole building. In that context, 3/4 gallon is probably next to nothing.
posted by jon1270 at 10:56 AM on January 10, 2011 [1 favorite]
posted by jon1270 at 10:56 AM on January 10, 2011 [1 favorite]
Because those hygrometers are designed for cigar humidors. My humidor is about .5 cu ft, which I'm guessing is a lot smaller than your office. You are using the wrong tool for the job.
posted by fixedgear at 11:03 AM on January 10, 2011
posted by fixedgear at 11:03 AM on January 10, 2011
Here's a good humidity sensor thats meant for measuring in a room.
posted by Confess, Fletch at 11:12 AM on January 10, 2011 [1 favorite]
posted by Confess, Fletch at 11:12 AM on January 10, 2011 [1 favorite]
Hygrometers measure the RH of the air that comes into contact with their sensors, whether they're mounted in a humidor or a stadium. The electronics in the cigar humidor may be optimized for humidity levels considered ideal for cigar storage, but the size of the room doesn't matter a bit.
posted by jon1270 at 11:27 AM on January 10, 2011 [1 favorite]
posted by jon1270 at 11:27 AM on January 10, 2011 [1 favorite]
Response by poster: @ fixedgear: Maybe I wasn't very clear in the op. I have FOUR hygrometers, all different brands, 2 digital, 2 analog, located in different parts of the office. All read the same thing. Only the Western Digital one is a compact/humidor hygrometer. I was aware it's used for humidors when I bought it... that is irrelevant. My other 3 hygrometers were built for measuring room humidity. Besides, that shouldn't even matter as jon1270 pointed out; all hygrometers do the same thing.
posted by cuddles.mcsnuggy at 11:54 AM on January 10, 2011
posted by cuddles.mcsnuggy at 11:54 AM on January 10, 2011
I'm pretty sure jon1270 and JMOZ have the correct answer.
posted by Juffo-Wup at 11:55 AM on January 10, 2011
posted by Juffo-Wup at 11:55 AM on January 10, 2011
If you want to do some troubleshooting, put your humidifier and all your hygrometers into a closet or other such small room. Turn on the humidifier, then come back and check everything in a few hours.
If the hygrometers all read higher - as I suspect they will - then the problem is your office itself, as jon1270 and JMOZ point out.
posted by ErikaB at 2:47 PM on January 10, 2011
If the hygrometers all read higher - as I suspect they will - then the problem is your office itself, as jon1270 and JMOZ point out.
posted by ErikaB at 2:47 PM on January 10, 2011
I agree that your building's HVAC system is overpowering your humidifier's efforts. In order to humidify your office enough to see a difference in your hygrometers' readings, you'd need to close off all the air supply and return vents, then close the door and any windows, effectively making your office a closed box.
posted by exphysicist345 at 5:21 PM on January 10, 2011
posted by exphysicist345 at 5:21 PM on January 10, 2011
Response by poster: Good points. Thanks everyone!
posted by cuddles.mcsnuggy at 6:24 AM on January 11, 2011
posted by cuddles.mcsnuggy at 6:24 AM on January 11, 2011
This thread is closed to new comments.
posted by cuddles.mcsnuggy at 10:33 AM on January 10, 2011