My apartment is very humid, and so are my outdoor surroundings, so I’m going to buy a dehumidifier to stop the mold.
The choice is between a small dehumidifier that can remove 13 ounces of water a day from the air, and a medium one that can remove 25 ounces of water per day from the air. There is about a $30 difference between the two devices, the smaller being cheaper.
My question is, just how much moisture is there in the air of an 800-square foot apartment? If the small dehumidifier did its job and removed thirteen ounces of water a day, would that be enough to make a meaningful, noticeable difference in the humidity?
Or does the medium, remove-25-ounces-a-day device have to be purchased instead?
Ok. Assuming it’s about 76 Farenheit in your apartment, and 90% relative humidity, https://www.ready.noaa.gov/READYmoistcal.php, there are 19 grams of water per cubic meter.
8 feet is the standard residential ceiling height, and you said 800 square feet. 800 * 8 = 6400 cubic feet, or 181 cubic meters. So, there are 19*181 = 3439 grams of water potentially in the air.
That’s 121 ounces. Well.
Realistically, these numbers aren’t good enough to make a decision from. You asked “how much moisture *can *the air inside a 1-bedroom apartment contain.”
What you actually need to know is (1) What relative humidity is inside the apartment now, (2) what relative humidity is enough for mold growth. Normally, it’s 70% or more. (3) What the humidity is outside. See, air exchange is about once an hour or more. So there’s little point in dehumidifying if the outside air contains enough moisture for mold growth, because you’ll never dry the air enough before wet outside air replaces it. In most climates, the outside air *isn’t *wet enough for mold growth, so the actual reason you’re getting mold in your apartment is something is adding moisture to the air faster than it gets removed. (for instance, leaking plumbing, leaking roofs and walls, etc creating perpetually wet areas)
The tool that measures this is a humidistat. A wet-bulb thermometer also acts to give you this information.
Then, you can use that calculator I linked and determine how much moisture needs to be removed.
One final comment. This is springtime verging on summer. I was just researching air conditioners yesterday, and read several comments about the disaster you get if your AC condensate drains are plugged. Are you sure your A/C is doing it’s job and the condensate is leaving the apartment?
For that matter, you do know what a dehumidifier usually is. It’s just an A/C unit where the outside and inside parts (evaporator/compressor/condenser) are packaged into one box. It costs just as much money to run as an A/C unit, it just doesn’t cool anything down (it acts like a heater instead). Generally you’d be better off just running your A/C more, because lowering the inside temperature also reduces the absolute humidity.
Which is why you use the A/C to demist your car windscreen in the morning, even when it’s cold outside.
And you really wouldn’t like it if you did extract **all **the moisture from the air in your rooms.
First of all, are you sure you have your units correct? 13 ounces is something like 350ml and that’s the volume of a soda can. A dehumidifier that extracts a soda can worth of water in a day is hardly dehumidifying.
Second, the amount of moisture can’t be calculated without knowing the room temperature and relative humidity, not to mention the cubic volume of the room instead of the area.
Third, calculating the amount of water vapour in a room is hardly a factor in helping to decide what size dehumidifier you need. Depending on how humid your room is now and how low you want to decrease it to, you’ll probably going to need a machine that can extract anywhere from six to 12 liters in a 24hr period, considerably more than the 13 or 25 ounce machine you’re currently looking at.
Never mind.
The numbers have to be off. A dehumidifier can remove gallons of water a day from an apartment that size. Each person in that apartment can easily sweat and exhale 1 ounce of water per hour.
I can believe this is true for heating systems that have to bring in fresh combustion air, but that’s only during heating season. To my knowledge, air conditioning systems don’t exchange indoor air with outdoor air at all; the only exchange would happen when you open outside doors/windows, or whatever air happens to come through the myriad gaps and leaks in the construction of the building, but I’m pretty sure that’s all small compared to what a furnace does for you in the wintertime.
This dehumidifier removes 40 pints of water a day. You’ve got to be wrong on that 13 ounce number. Are you looking at some kind of container of hygroscopic chemicals? Because those are crap.
You exhale somewhere around a liter of water in your breath every eight hours – so if that thing is really 25 ounces, it won’t even remove the water vapor you exhale while you’re sleeping.
Thanks for the advice everyone, I ended up buying a 30-pint dehumidifier and I think it removed a gallon in just six hours.