Questions for people who use dehumidifiers (allergy, cold, skin, sores)

[movingvanmorrison]

I have allergies to dust and dust mites and finally had to buy a dehumidifier because my house was so humid and dust mites were causing me to have sores on my chest, shoulders and neck.

So I bought one. I have read that keeping the humidity below 50% is key but it's hard to do. I have to move it from one room to another. I bought one for an area much larger than was needed for my small house but it just doesn't work except for one room at a time.

I especially want to hear from people who have dust mite allergy, but anyone is welcome to comment, especially if you use a dehumidifier for health purposes.

So I have a few questions about dehumidifying and mites, if you can answer at least one please do:

1) do you have to run it 24/7 to keep dust mites from reproducing? Or can you run it at under 50% humidity for 2-3 hours then stop it for awhile, then run it again? My idea - to save electricity and save the motor - is to run it in the bedroom til it reaches 47% or so, leave it there for 2-3 hours, then move it to the living room/kitchen til that reaches at least 50% for a couple hours, then turn it off for most of the day, turning it back on in the evening in the bedroom to get it down to 47% or so before bed then sleep, then turn it back on...
Or do I really need to run it in the bedroom while I sleep?

2) I understand that when you reach under 50% it kills the dust mites. So how long does it take for more to be born and become bothersome again? 2 hours? 8 hours? (Where the heck to these things COME FROM anyway, and how long does it take them to be born and start eating your dead skin etc again?

3) The Dehumidifier instructions says to keep the windows closed. But would it be okay to open the windows when it's not "that humid" outside in the living room while the bedroom (where the dehumidifier is) is closed up? Or does one really have to keep all windows in the house closed all day long?

I do not have air conditioning so it gets quite hot without opening windows at all. I realize that opening the windows does let in some humidity but I then do close the windows and run the dehumidifiier in there later when it cools off.

NOTE:
1) I use a mite prevention mattress cover on one twin bed but have a 2nd twin bed in the bedroom without one. That bed is not currently being slept in.
2) I have a HEPA type air filter with UV and negative ions as part of it and I run that in the bedroom and living room about half time each room.
3) I wash and dry my bedclothes in hot water and hot air once a week or so.

The dehumidifier seems to be working well, I have had no skin issues since getting it. However I am STILL getting allergies and asthma but that could be from the exposure to dust and pollens I get OUTSIDE...


Just as a point of reference, my dehumidier is removing between 5-7 quarts of water per day.

[RamenAddict]

I lived in a beach area condo. The AC did fairly well at dehumidifying on hot days, but in spring/fall, the house could easily get to 70% humidity. The dehumidifier was running all day in fall/spring. I had it in a hall area outside my bedroom, as the intake for my AC was a few feet away. Even with that, I had to keep closet doors open during the day because clothing on the side of the building near the walls would mildew. I ended up getting the damp rid in those places.

I’m not actually sure how long it takes them to grow. I know when I was leaving the house to go to work, it would sometimes fill and be above 50%, but I did not have extremely significant symptoms. I did have more symptoms in my last apartment, but they had construction going on all the time and I just ended up with insane construction dust blowing in from outside and the hallway.

FWIW, now it is not humid/dry here but I still have some symptoms due to pollen. Spring for me is the really itchy skin time.

[terracore]

Dehumidifiers and air conditioners are basically the exact same technology: a heat pump. The only difference is that an air conditioner blows the hot, humid air outside, and cold, dry air inside. Dehumidifiers blow both temps into the room it's running in, but warm will always win because of inherent inefficiencies in the technology. The water gets condensed into a tank instead of dripping out of the hot side of your A/C. Running either one with windows open is a waste of money because the humidity will come in through the window. It's like leaving your refrigerator door open and wondering why your food isn't cold (refrigerators are also basically the same heat pump technology).

It sounds like you need to run a dehumidifier when it's cold and an A/C when its warm. They do make A/Cs with a "dehumidifier" setting but don't be fooled, they are still going to cool the house somewhat, and won't dehumidify at the same efficiency as the A/C setting.

Unless your electricity is really cheap, you probably want to avoid using a "portable" A/C unit that uses hoses to push the hot air outside. They are horribly inefficient. A window unit has the "hot" part of the appliance outside the house and the heat is easily vented while the cold, dry air is blown inside. In a portable unit the hot part of the unit is inside the room with you, and the device spends a great deal of it's electricity trying to overcome the fact that the hot part is supposed to be outside.

TL;DR: Air conditioners and dehumidifiers are the same thing, the difference being where the air is vented.

[movingvanmorrison]

Originally Posted by RamenAddict

I lived in a beach area condo. The AC did fairly well at dehumidifying on hot days, but in spring/fall, the house could easily get to 70% humidity. The dehumidifier was running all day in fall/spring. I had it in a hall area outside my bedroom, as the intake for my AC was a few feet away. Even with that, I had to keep closet doors open during the day because clothing on the side of the building near the walls would mildew. I ended up getting the damp rid in those places.

I’m not actually sure how long it takes them to grow. I know when I was leaving the house to go to work, it would sometimes fill and be above 50%, but I did not have extremely significant symptoms. I did have more symptoms in my last apartment, but they had construction going on all the time and I just ended up with insane construction dust blowing in from outside and the hallway.

FWIW, now it is not humid/dry here but I still have some symptoms due to pollen. Spring for me is the really itchy skin time.

Thanks for your feedback.
I have always had allergy to dust (and dust mites) but I lived in a dry climate so it wasn't too bad.
When i moved to a very humid climate without a.c. (I was comfortable enough with just a couple fans, though many would not have been) I began to have asthma and allergies worse than in the previous 20 years. (Oh, I'm also allergic to mold, which we get here too, wouldn't you know it?)

So while I had always had asthma and allergies from dust, this was the first time I had the mites so bad in my bedroom apparently, that I developed sores on my chest, neck and shoulders from them. Took a while to even diagnose what it was. But the dehumidifier so far is helping.

I'm just trying to understand the optimal way to use it, whether or not I need to use it ALL the time or if I can turn it on and off to give it a rest, give myself a rest from the noise, and save electricity.

I'm experimenting now with turning it off at last a few hours a day and then running it in the evening when it tends to be more humid and all night while I sleep.

[movingvanmorrison]

Originally Posted by terracore

Dehumidifiers and air conditioners are basically the exact same technology: a heat pump. The only difference is that an air conditioner blows the hot, humid air outside, and cold, dry air inside. Dehumidifiers blow both temps into the room it's running in, but warm will always win because of inherent inefficiencies in the technology. The water gets condensed into a tank instead of dripping out of the hot side of your A/C. Running either one with windows open is a waste of money because the humidity will come in through the window. It's like leaving your refrigerator door open and wondering why your food isn't cold (refrigerators are also basically the same heat pump technology).

It sounds like you need to run a dehumidifier when it's cold and an A/C when its warm. They do make A/Cs with a "dehumidifier" setting but don't be fooled, they are still going to cool the house somewhat, and won't dehumidify at the same efficiency as the A/C setting.

Unless your electricity is really cheap, you probably want to avoid using a "portable" A/C unit that uses hoses to push the hot air outside. They are horribly inefficient. A window unit has the "hot" part of the appliance outside the house and the heat is easily vented while the cold, dry air is blown inside. In a portable unit the hot part of the unit is inside the room with you, and the device spends a great deal of it's electricity trying to overcome the fact that the hot part is supposed to be outside.

TL;DR: Air conditioners and dehumidifiers are the same thing, the difference being where the air is vented.

Thanks very much for your info. I knew that a.c.'s did take some water out but never considered getting one to do that because I figured it would not be efficient enough at that to solve my problem.

Now, had I bought an a.c., according to your post, I realize it would not have been a good thing because I don't have a window to put it in. All my windows are very large. I'd have to cut a hole in the wall just right and put one in there, run a 220 line to it etc - more than I am willing to spend to do. I would have had to buy a portable one which you say would not work well.

So for now I'll stick with the dehumidifier which I just bought.
As to opening windows what I have been doing is opening the windows in the living room/kitchen while keeping the door closed in the bedroom with the dehumidifier running. Also it is not super humid out, maybe around 60%. So it seems to be working for me that way. I get fresh air in the living room/kitchen while dehumidifying the bedroom which has both the dehumidifier and an air filter (hepa/ions/uv).
So far this strategy seems to work pretty well. I also move the air filter back and forth from the bedroom to the living room /kitchen.


In the evening I run the dehumidifier for awhile in the living room with the windows mostly closed, just a couple slightly open to let some fresh cooler air in, and a fan when needed.

Am I wrong to think that getting fresh air into the house is important even if it includes some humidity, dust and pollen? Or should I really keep my house closed up most of the time with the dehumidifier on? I would almost prefer to keep the windows mostly closed because I don't want pollen and dust to enter. BUT at the same time is there no real value to "fresh air"? Not sure.

[Parnassia]

Originally Posted by movingvanmorrison

Thanks very much for your info. I knew that a.c.'s did take some water out but never considered getting one to do that because I figured it would not be efficient enough at that to solve my problem.

Now, had I bought an a.c., according to your post, I realize it would not have been a good thing because I don't have a window to put it in. All my windows are very large. I'd have to cut a hole in the wall just right and put one in there, run a 220 line to it etc - more than I am willing to spend to do. I would have had to buy a portable one which you say would not work well.

So for now I'll stick with the dehumidifier which I just bought.
As to opening windows what I have been doing is opening the windows in the living room/kitchen while keeping the door closed in the bedroom with the dehumidifier running. Also it is not super humid out, maybe around 60%. So it seems to be working for me that way. I get fresh air in the living room/kitchen while dehumidifying the bedroom which has both the dehumidifier and an air filter (hepa/ions/uv).
So far this strategy seems to work pretty well. I also move the air filter back and forth from the bedroom to the living room /kitchen.


In the evening I run the dehumidifier for awhile in the living room with the windows mostly closed, just a couple slightly open to let some fresh cooler air in, and a fan when needed.

Am I wrong to think that getting fresh air into the house is important even if it includes some humidity, dust and pollen? Or should I really keep my house closed up most of the time with the dehumidifier on? I would almost prefer to keep the windows mostly closed because I don't want pollen and dust to enter. BUT at the same time is there no real value to "fresh air"? Not sure.

Well, "fresh" is relative. Closed up, your house does add its own ingredients to the air: offgassing and particulates from all the contents and surfaces, from all the chemicals you use, byproducts from heating, from cooking, to everything the inhabitants exhale including carbon dioxide. If you have lots of live houseplants they contribute oxygen. More modern houses tend to be sealed better and studies have shown that indoor air quality can actually be worse because of that, plus all the residues from materials we finish surfaces with and import into those spaces. There's less "leakage" from outdoors to indoors and vice versa. Your house isn't hermetically sealed after all and you wouldn't want it to be. You do come and go periodically right? Allowing "fresh" air in will allow exchange between what's outside and what's inside. It will inject whatever's floating around in it...pollens, dust and particulates from other sources, moisture, etc. As they say, dilution is the solution to pollution. The definition of "pollution" varies.

[movingvanmorrison]

Originally Posted by Parnassia

Well, "fresh" is relative. Closed up, your house does add its own ingredients to the air: offgassing and particulates from all the contents and surfaces, from all the chemicals you use, byproducts from heating, from cooking, to everything the inhabitants exhale including carbon dioxide. If you have lots of live houseplants they contribute oxygen. More modern houses tend to be sealed better and studies have shown that indoor air quality can actually be worse because of that, plus all the residues from materials we finish surfaces with and import into those spaces. There's less "leakage" from outdoors to indoors and vice versa. Your house isn't hermetically sealed after all and you wouldn't want it to be. You do come and go periodically right? Allowing "fresh" air in will allow exchange between what's outside and what's inside. It will inject whatever's floating around in it...pollens, dust and particulates from other sources, moisture, etc. As they say, dilution is the solution to pollution. The definition of "pollution" varies.

Thanks for the info.
I don't use any chemicals at all in my house unless you would count shampoo, soap, (both "natural" brands). I do use a tiny bit of Lysol in the garbage pail after I remove the plastic bag to take it for pickup, but I take it outside to spray it and let it sit for awhile usually before bringing it in.

So probably off-gassing isn't a big issue. I have ceramic floors, wooden chairs, a sofa that I've had for years... I do use a gas stove and gas dryer but do open the windows a bit when I use those.

Right now I am figuring that if I open a couple windows for a little while each day that should be enough.
The air filter I have is a HEPA type and also gives out healthy negative ions and has a UV light to kill mold etc. and I move that back and forth with the Dehumidifier.

So if what you say is true, and it seems reasonable to me that it is, then probably I'll be alright leaving my house "mostly" closed up. I sure do enjoy the drier air and hardly any smell of mold/mildew.

[ocpaul20]

How do you know the problem is dust mites?

Folks who are allergic to things like house dust mite and hay fever, pollen, and things like that are often allergic to a cocktail of stuff. Docs seem to test for the common ones with a needle prick test, so that may be the way you were tested too. I notice you have an old sofa probably with masses and masses of dust in it too. What about carpets?

Have you tried changing your diet? Like cutting out all diary and cheese, milk for a week and noticing any differences? Do you get asthma too (I do). I did quite well when I cut back to eating each day within a 4 or 8 hour period in 24 and only drinking water/black coffee during the day.

Just a point about dehumidifiers - we had a clothes shop (not in the USA) with a outhouse where we kept the stock, clothes, extra sizes, etc. In that, we had no heating but a dehumidier going all the time to make sure there was no damp. However, it pulled all the moisture out of the walls and the plaster covered with paint bubbled up as the water was pulled out from the wall.

[movingvanmorrison]

Originally Posted by ocpaul20

How do you know the problem is dust mites?

Folks who are allergic to things like house dust mite and hay fever, pollen, and things like that are often allergic to a cocktail of stuff. Docs seem to test for the common ones with a needle prick test, so that may be the way you were tested too. I notice you have an old sofa probably with masses and masses of dust in it too. What about carpets?

Have you tried changing your diet? Like cutting out all diary and cheese, milk for a week and noticing any differences? Do you get asthma too (I do). I did quite well when I cut back to eating each day within a 4 or 8 hour period in 24 and only drinking water/black coffee during the day.

Just a point about dehumidifiers - we had a clothes shop (not in the USA) with a outhouse where we kept the stock, clothes, extra sizes, etc. In that, we had no heating but a dehumidier going all the time to make sure there was no damp. However, it pulled all the moisture out of the walls and the plaster covered with paint bubbled up as the water was pulled out from the wall.

I've had allergies most of my life. I had tests done that showed I was allergic to dander, dust and mold and pollen many years ago.
I have found that my meds just don't always do the trick when something I'm allergic to is present in a great quantity.
Yes, asthma too and it is much better in dryness as opposed to moistness.
I bought the dehumidier because I developed sores on my skin and the dermatologist couldn't figure out what they were caused from but eventually a MD and I came to the conclusion it was dustmites.
AND I then found that by washing the bedclothes in hot water once a week, using a anti-mite mattress cover
and using a skin cream where the allergy to the mites were, it went away.

But there is a ton of humidity here and the only way to get rid of the mites is to keep the humidity under 50%, or so I've read.

I still haven't figured out how long the air has to be under 50%, to kill them; and how long it can be over 50% for more to come back...

But these steps I have taken are working pretty well. No more sores, but still itchy skin on my shoulders where the sores were (also were on my chest and neck).

The thing is, I knew most of my life that the mites would cause runny nose and asthma, but never knew they could cause sores. But it was super humid in my bedroom and had been for months, so I guess the mites got worse and thus this new symptom appeared.

For those of you who may have this problem, the dehumidier is a god send. However, it does make the bedroom hotter and at times too hot. But I deal with it because I'd rather be hot(ter) and dry than to be less-hot and humid.

Thanks to you folks for weighing in. I'm still looking for the answer re how long it takes mites to die and how long it takes them to populate again and at what humidity level. It's probably on the net somewhere IF anyone even knows the answer; but so far I haven't found it. So I'm just trying to keep the humidty in the bedroom below 50% most of the time.

[ocpaul20]

You can also try air filters, and vacuuming beds, sofas, carpets, and in fact plain boards are probably better than floor coverings since boards can be mopped and do not harbour or re-circulate the dust, etc. Particularly in bedrooms where you sleep.

I notice you did not answer the questions about diet, because it is a biggie and important. Our bodies should be able to handle within reason anything we throw at it - as long it has a strong immune system. Thats where diet comes in, because unless you are eating the right stuff your immune system will be weak. Loads of sugar, fizzy drinks, dairy, extra weight, etc all puts extra pressure on the systems of the body which are supposed to keep us ticking along.

I know it is not a popular thing to say, but our health is our responsibility and as we get older, it is more likely to suffer and not be able to overcome the crapola we shove into our body. It is easy to pop a pill and continue on, but more difficult to start to take control of our life and sort out our health problems. Good luck.