Dehumidifier?

alexey75 wrote:
Hello guys,

Snip..

We’re pretty big family, every morning all windows covered with moisture.

This specific model probably not big enough for 28 ft trailer…

I agree with the others, that small dehumidifier will not stop the issue, it is way too small. The larger compressors dehumidifier will help, there are few things I may be able to add that can help not yet mentioned. But need a little more info to make sure we all understand the problem right. And for the campers sake, you need to get the excess humidity issue under control if you plan to keep that camper a long time. I have seen first hand doing roof replacements what lack of moisture control can do inside a typical RV attic.

You are posting this question in June and not winter time, what are the outside temperatures at night when you have this problem?

How big is the family? (how many)

Where are you located that this occurs in June? or what months does it occur?

Do you have access or can you get a Hygrometer? (humidity gauge) One like this or similar that has the last 24 hours hi and low saved on it for both RH (relative humidity)and temp.
https://www.amazon.com/AcuRite-Humidity-Thermometer-Hygrometer-Indicator/dp/B0013BKDO8/ref=sr_1_1?dchild=1&keywords=AcuRite+00613&qid=1625284354&s=home-garden&sr=1-1

These kinds of issues are normally reported in the winter months when the heat is running inside the camper and it is cold outside.

If we know some more about the above questions, we may be able to help better and all learn something here with this issue in June. If in fact it is happening in June.

Thanks

John

smthbros wrote:

pianotuna wrote:
We need to get the surfaces below the dew point.

I am pretty sure you miss-typed. To inhibit condensate formation we need to maintain surface temperature above the dew point. Also, a computer search for 'psychrometric chart' will yield several that allow inputting temperature and relative humidity to determine dew point and grains per pound of moisture in the air.

Thanks for catching that.

I often run an electric heater and the roof air to reduce humidity. So long as I have access to 30 amps of power (for example two 15 amp circuits) that works quickly and well.

alexey75 wrote:
Thanks guys. We open the vents when we take a shower or cooking, but still, every morning all windows covered with water.
About dew point, does it mean the windows inside should be about 46-50F, right? Usually we keep the temperature inside about 70F.

I see in general the compressor dehumidifier are more louder than desiccant, no?

The dew point varies. It is related to the temperature and the amount of humidity in the air at that temperature.

As far as noise it is less than a small window air conditioner running on low.

pianotuna wrote:
We need to get the surfaces below the dew point.

I am pretty sure you miss-typed. To inhibit condensate formation we need to maintain surface temperature above the dew point. Also, a computer search for 'psychrometric chart' will yield several that allow inputting temperature and relative humidity to determine dew point and grains per pound of moisture in the air.

alexey75 wrote:

About dew point, does it mean the windows inside should be about 46-50F, right? Usually we keep the temperature inside about 70F.

I see in general the compressor dehumidifier are more louder than desiccant, no?

No. Dew point is the temperature at which water vapor will condense on a surface. Check with one of the many weather websites until you find one that lists dew point.

Desiccant is quiet, but without a fan.....and really they don't work well where I live.

alexey75 wrote:
Thanks guys. We open the vents when we take a shower or cooking, but still, every morning all windows covered with water.
About dew point, does it mean the windows inside should be about 46-50F, right? Usually we keep the temperature inside about 70F.

I see in general the compressor dehumidifier are more louder than desiccant, no?

For most practical purposes, keeping the windows at or below the dew point is not very practical. We like it cold at night for sleeping and no it does work.

About the only way to do it would be to add an interior layer to mimic dual pained windows (kind of an interior storm window). But even there the frames will still tend build up moisture.

Drying out the air is really the solution for cold weather camping.

Thanks guys. We open the vents when we take a shower or cooking, but still, every morning all windows covered with water.
About dew point, does it mean the windows inside should be about 46-50F, right? Usually we keep the temperature inside about 70F.

I see in general the compressor dehumidifier are more louder than desiccant, no?

Nothing beats a compressor dehumidifier. Having said that we run a small dehumidifier like the one you linked to. We use it in our 16 foot when stored. In this high temperature and humidity area it will fill in about 4 days. It is better than nothing and we have never been bothered by mold or mildew. With your load you will need a larger compressor style.

pianotuna wrote:
They rate dehumidifiers at 77 F. (25 c). When it is colder than that the collection of moisture is quite poor.

The reason for electric heat is to warm air coming into the rv from a window. We need to get the surfaces below the dew point.

Ours seems to do well even down to about 60F. below that it drops off pretty quick.

and yes, you want surfaces below the dew point, which in a trailer with single pane windows can be quite difficult!

They rate dehumidifiers at 77 F. (25 c). When it is colder than that the collection of moisture is quite poor.

The reason for electric heat is to warm air coming into the rv from a window. We need to get the surfaces (temperature on surface above) the dew point.

fixed a typo. Thanks for pointing it out.