Environmental Graph Interpretation


Are there any one the list that would care to take a look at some graphs of
temperature, relative humidity and dew point that I have for two locations.
In one of the two locations, I'm having a problem with the floor getting wet
(condensation?). At the other everything is just fine.

I need to understand what these graphs are telling me about the problem and
if a simple dehumidifier would solve my moisture problem.

Any takers?

Oh, the environmental monitor I installed in each location is the IT
Watchdog from Geist Global. I bought the POE version. Installed like a
charm and was $229 plus shipping.

I do wonder if this question is off topic, but then I can hear myself saying
"Hey, I'm Operating a Network, here! In North America!" And then I think,
"Yep, on topic!"



Lorell Hathcock

SolStar Network, LLC



FTTH - Commercial - Residential

Burglar - Access Control

956-478-5955 (cell) - 956-316-4090 (main)

<mailto:lorell@SolStarNetwork.com> lorell@SolStarNetwork.com

<http://www.solstarnetwork.com/> www.SolStarNetwork.com

TX License #B19998

Is your moisture problem on a ground floor? Note that even well-cured concrete
is like 30% water, and can allow moisture to slowly migrate through and
weep. Usual cure is application of a proper sealant over the concrete.

It is on the ground floor, but it is in a hut that has a wood floor that is
raised off the ground. There is a gap between the bottom of the floor and
the ground.

My guess is that your floor is not insulated. The air temperature in
the room is higher than a temperature of the floor, hence, the floor
starts sweating. Where are your temperature sensors installed? Do you
have one of them measuring the air temperature in the room and the
other located on the floor? What readings they show? I'd use a temp.
gun to measure the floor temp (if you have only one sensor installed).
and see if you have a considerable temp. difference between those two

I'd say you won't have this problem if you insulate the floor (if
possible). Another option is A/C - it will help to control the temp
and decrease humidity. A dehumidifier should help too but it wouldn't
be my choice...

If there are heat producing devices in the room, it sounds implausible
for condensation to occur in significant amounts unless the climate is
very, very humid.

RH sensors are often very inaccurate, but you can get the indoor dew
point from the RH and the temperature[1], and if the floor is warmer
than the dew point there can be no condensation. If it is below the dew
point, there will be condensation - but the outside air cannot be colder
than its own dewpoint, so in this case something must be adding water
vapor to increase the absolute humidity in the room, or the floor must
be cooled by something other than outside air. (Or the temperature [and
dew point] of the outside air must be constantly falling while the indoor
air is lagging behind. This can only be a transient situation, and the
reverse should happen at some point, drying the floor again)

1: http://andrew.rsmas.miami.edu/bmcnoldy/Humidity.html