A LOT of condensation on widows and sills

[teddy bear]

Actually this home was completely gutted about a year ago due to having Chinese drywall. Since I was basically the contractor and sub contracted everything out, I just don't know what to think. Obviously we never had this problem the first time we built this home. The house has a constant musty smell in between cooling and heating seasons, so I take it that this is where the high humidity is coming into play.

Keeping a home cooled below outside dew points can also cause condensation of moisture in the insulation while outside dew points are high. Best to not overcool homes while outside dew points are +70^F. Should dryout during cold weather and heating.
Attaching data from a SW FL home with a/c-dehumidification-fresh air ventilation for 2 weeks, followed by cool dry weather without a/c or dehumidification. Observe the lower inside dew point while the outside dew points are high. During not dehu or a/c, the inside dew point follows the outside dew point. Additional fresh dry air ventilation reduces the humidification effect from the occupants. Fresh air ventilation and dehumidification are important for air tight well insulated homes.
Regards TB
Attaching PDF file. Click on the pdf to veiw.
Cape Coral FL Home Jan 2013.pdf

[energy_rater_La]

what is exterior cladding of the home?
what type of underlayment was used between brick
and insulation in stud bays?
was a vapor barrier used behind sheetrock to interior?

knowing that this is a retrofit rather than a new construction home
raises more questions.

determining where the moisture is comming from, internal gain..or something else
is what you need to know.

best of luck.

[stvc]

This is the part that is still raising my eyebrow, the OP states "when the heater kicks on, the humidity in the house shoots up all of a sudden"

Since he didn't provide the numbers I'll just guess and say he's going from 65F/60% RH to 70F. A quick look at the psyometric chart tells me the RH should drop to about 50%. Something just isn't right here.

If the op could post some pictures that may help.

[tedkidd]

Hello all! I live in south Alabama and the past few nights the temp. has gotten around 35-39 degrees. I have a brand new Trane 16 seer variable speed heat pump with a thermostat that has humidity control. I keep my set temp. at 70 degrees when i go to bed. The next morning, I have pools of water on my window sills and the windows have droplets of water all over them and are also fogged over.

70F, 70RH, DEW POINT IS 60F. I SUSPECT THERE IS WATER ON SURFACE OTHER THAN WINDOWS AND SILLS.

I have also noticed when the heat is running, it is putting my humidity level between 64 and 70. To me that doesn't sound normal.

BUT NOT SURPRISING IF THAT'S WHAT YOU ARE ASKING FOR. (what rh does the stat call for?!)

Does the high humidity level have something to do with this? Also, the house is a new home with upgraded insulation. The windows are double paned, but are metal, not vinyl, which I don't think the winows have anything to do with what's going on.

SINCE THE WINDOWS ARE THE CONDENSING SURFACE, THEY CERTAINLY HAVE SOMETHING TO DO WITH WHAT IS GOING ON. BUT DISTINCTION BETWEEN PARTICIPANT AND CULPRIT WILL AVOID WILD GOOSE CHASES.

I guess the humidity control doesn't work unless the a/c is running, correct?

INCORRECT

What the heck is going on? I'm really getting frustrated. Thanks for any help that can be offered.

Chad

Chad, is there a reason you haven't answered stvc's question repeated numerous times?

If you have a humidifier, and it's not properly set to deliver humidity only when it gets dry, that may explain everything.

[clllclal]

what is exterior cladding of the home?
what type of underlayment was used between brick
and insulation in stud bays?
was a vapor barrier used behind sheetrock to interior?

knowing that this is a retrofit rather than a new construction home
raises more questions.

determining where the moisture is comming from, internal gain..or something else
is what you need to know.

best of luck.

The exterior is brick. Under the brick is plywood wrapped in tyvek. No vapor barrier in between sheetrock and insulation. I didn't think a vapor barrier was needed in that situation.

[clllclal]

Chad, is there a reason you haven't answered stvc's question repeated numerous times?

If you have a humidifier, and it's not properly set to deliver humidity only when it gets dry, that may explain everything.

Let me explain something. I am not an HVAC expert. As I've stated quite a few times, I really appreciate all of the feedback being given. And no, I didn't realize that I wasn't answering a question that was being asked by stvc. If I am correct, you can only set the humidity level to what you would like it to reach in the cooling stage, but that doesn't mean that I have a dehumidifier built in with the system. Also, with the heat running, the humidity level and the heater do not work together in heat mode that I am aware. Maybe I am way off base here, but this is how I understand it. This is not my actual tstat, but it is identical to it. I pulled this one off of the internet.

[tedkidd]

Can you post a few pictures of your air handler? We'll be able to tell you if you have a humidifier installed.

Communicating equipment manages HUMIDIFICATION as well as dehumidification.

[clllclal]

Can you post a few pictures of your air handler? We'll be able to tell you if you have a humidifier installed.

Communicating equipment manages HUMIDIFICATION as well as dehumidification.

This is the air handler that is located in the attic. There is nothing there that tells me I have a dehumidifier as well. At least I know I didn't pay for anything like that.

[energy_rater_La]

Chad, we know you aren't a hvac expert.
just as you know that we are toubleshooting via internet.
there are limits to both.

I asked about wall construction thinking about moisture driven thru brick exterior.
this article (that you'd have to download) explains it well.

http://www.buildingscience.com/docum...ure+brick+wall

we would be remiss in only addressing the RH without exploring why it is so high.
as different folks chime in, and more information is posted..more questions are asked.

are you game for a few more questions?
you have cellulose insulation in walls and on attic floor..correct?
was the insulation in the walls wet blown when installed?

[tedkidd]

That's a pretty nice looking installation EXCEPT the emergency drain pan looks like its got water in it. Hard to tell from the picture, but the bottom looks reflective and the wood looks wet.

That drain pan should always be dry.

So where is that water coming from? I suspect there is a humidifier somewhere. (The dehumidifier is the AC Coil - in summer it gets cold and becomes a condensing surface. Water drains out those little white pipes.)

More pictures please?

[clllclal]

Chad, we know you aren't a hvac expert.
just as you know that we are toubleshooting via internet.
there are limits to both.

I asked about wall construction thinking about moisture driven thru brick exterior.
this article (that you'd have to download) explains it well.

http://www.buildingscience.com/docum...ure+brick+wall

we would be remiss in only addressing the RH without exploring why it is so high.
as different folks chime in, and more information is posted..more questions are asked.

are you game for a few more questions?
you have cellulose insulation in walls and on attic floor..correct?
was the insulation in the walls wet blown when installed?

Yes, I am game for a few more questions. The cellulose in the walls was wet blown. That was well over a year ago.

[clllclal]

That's a pretty nice looking installation EXCEPT the emergency drain pan looks like its got water in it. Hard to tell from the picture, but the bottom looks reflective and the wood looks wet.

That drain pan should always be dry.

So where is that water coming from? I suspect there is a humidifier somewhere. (The dehumidifier is the AC Coil - in summer it gets cold and becomes a condensing surface. Water drains out those little white pipes.)

More pictures please?

That picture is over 8 months old. The water that you see has been alleviated. The emergency drain pain has not been wet since. I do understand about the AC coil being a dehumidifier during the summer months when it is cooling. The way you made it sound earlier was as if I had a dehumidifier along with the AC unit. Exactly which angle pictures would you like?

[stvc]

That picture is over 8 months old. The water that you see has been alleviated. The emergency drain pain has not been wet since. I do understand about the AC coil being a dehumidifier during the summer months when it is cooling. The way you made it sound earlier was as if I had a dehumidifier along with the AC unit. Exactly which angle pictures would you like?

So where did the water come from the first time and what was done to correct it? Again, have you discussed this with your HVAC contractor?

A humidifier is another question that I think you said you did not believe you had, typically mounted on the supply duct but could also be on the return. Very common here, probably not so much there though. The more pictures the better we will be able to assess the situation without being there. I also was asking about inside/outside temp and humidity set points. Do you still use AC during the daytime?