A LOT of condensation on widows and sills

[clllclal]

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. 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. 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. I guess the humidity control doesn't work unless the a/c is running, correct? What the heck is going on? I'm really getting frustrated. Thanks for any help that can be offered.

Chad

[George2]

New homes tend to have high humidity due to the new materials,i.e., lumber and plaster or drywall. Your level of humidity is way too high. New homes are built to much tighter standards, installing a fresh air intake might work for you. I know that HVAC in the south must be an entirely different animal because of the high outdoor humidity.

[jazpek]

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[jpsmith1cm]

jazpek

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[energy_rater_La]

window choice has everything to do with it.

metal is an excellent conductor of heat/cold.
the window frames contribute to the condensation.
look at the window numbers..solar heat gain coefficients
and u-factors.

a double paned vinly with low e coating will have a .37 shgc & u-factor.
take that same insulated glass unit and put it into a metal frame
and these numbers jump to .57 shgc & ufactor.

as it gets cold outside, these temps transfer thru the metal.
even thermal break doesn't stop the transfer.
so when the cold of the outer frame reaches the warm of
the inner frame..they condensate.

granted new construction materials may contain higher moisture
content. this usually settles down to normal range in a full
heating cooling season.

adding supplimental dehumidification helps, but this is really
a poor window choice that has been made.
in the summer time condensation will be to exterior of
windows.

if hvac system is oversized, then in summer it will not run
long enough to dehumidify.
ideally 50% RH inside the home is what we try to achieve
in the south.

you may want to look into stand alone dehumidifiers.
if this works well then investing in a whole house
dehumdificiation sytem is a good choice.

best of luck.

[clllclal]

George2

What exactly is a fresh air intake? Also, what size dehumidifier would I need?(not the whole house type, just one you sit on the floor) The living area of the the home is 2200sf.

Thanks

Chad

[duckman06]

window choice has everything to do with it.

metal is an excellent conductor of heat/cold.
the window frames contribute to the condensation.
look at the window numbers..solar heat gain coefficients
and u-factors.

a double paned vinly with low e coating will have a .37 shgc & u-factor.
take that same insulated glass unit and put it into a metal frame
and these numbers jump to .57 shgc & ufactor.

as it gets cold outside, these temps transfer thru the metal.
even thermal break doesn't stop the transfer.
so when the cold of the outer frame reaches the warm of
the inner frame..they condensate.

granted new construction materials may contain higher moisture
content. this usually settles down to normal range in a full
heating cooling season.

adding supplimental dehumidification helps, but this is really
a poor window choice that has been made.
in the summer time condensation will be to exterior of
windows.

if hvac system is oversized, then in summer it will not run
long enough to dehumidify.
ideally 50% RH inside the home is what we try to achieve
in the south.

you may want to look into stand alone dehumidifiers.
if this works well then investing in a whole house
dehumdificiation sytem is a good choice.

best of luck.

This is a very good post. energyraterla is correct. The best double pane window with low e and thermal break still not hold a candle to good double pane vinyl window.

Over the years all the improvements to metal windows have really been non successful as one thing remains the metal frame which will conduct heat and cool. Think about it put a piece of metal and vinyl in the sun and wait just a few minutes which one gets hotter? The metal does plan and simple. While the low e and thermal break just address the glass not the metal frame.

It still amazes me that this day in time that buliders are still using metal windows? In the past when homes were not as tight people would not see the problems that you are due to the home having leakage. Over the past 20 years all the thought process of building a new home has gone to getting the House tigher and they have become so right in some cases that fresh air make up most be part of the heating and cooling systems so the home can breath.

Freash air makeup is when you introduce outside air into the home to allow it have healthy air changes per hour. While the humdity levels you are reporting are very high and need to looked at before any more damage is done to window sills, inside of the home etc... Depending on your home and how you run your system you would want in the winter for your home to be somewhere between 30-40% on average and during the summer 45-55% humdity levels. A good dehumditfer might be the answer to remove all the excess moisture in your home.

You say you have a Trane 16 seer heat pump. What are the model numbers of the system and how much aux. heat due you have? If the system is oversized during the summer your system will not run long enough to remove the humdity in the home and during the winter usually heat dries out the home but it is not designed to remove humidity like the a/c does. Dehumditfer again might be you best option to help with this. What does your builder and hvac installer have to say about the problem?

More then lickly in your home it is just really tight and the metal is conducting the opposite temp on the windows vs the indoor with the metal windows. I understand that this is not what you want to hear in a new home but this are things that you need to address before they get worse and while your home is still under warranty. Please keep us posted on the outcome!

[clllclal]

This is a very good post. energyraterla is correct. The best double pane window with low e and thermal break still not hold a candle to good double pane vinyl window.

Over the years all the improvements to metal windows have really been non successful as one thing remains the metal frame which will conduct heat and cool. Think about it put a piece of metal and vinyl in the sun and wait just a few minutes which one gets hotter? The metal does plan and simple. While the low e and thermal break just address the glass not the metal frame.

It still amazes me that this day in time that buliders are still using metal windows? In the past when homes were not as tight people would not see the problems that you are due to the home having leakage. Over the past 20 years all the thought process of building a new home has gone to getting the House tigher and they have become so right in some cases that fresh air make up most be part of the heating and cooling systems so the home can breath.

Freash air makeup is when you introduce outside air into the home to allow it have healthy air changes per hour. While the humdity levels you are reporting are very high and need to looked at before any more damage is done to window sills, inside of the home etc... Depending on your home and how you run your system you would want in the winter for your home to be somewhere between 30-40% on average and during the summer 45-55% humdity levels. A good dehumditfer might be the answer to remove all the excess moisture in your home.

You say you have a Trane 16 seer heat pump. What are the model numbers of the system and how much aux. heat due you have? If the system is oversized during the summer your system will not run long enough to remove the humdity in the home and during the winter usually heat dries out the home but it is not designed to remove humidity like the a/c does. Dehumditfer again might be you best option to help with this. What does your builder and hvac installer have to say about the problem?

More then lickly in your home it is just really tight and the metal is conducting the opposite temp on the windows vs the indoor with the metal windows. I understand that this is not what you want to hear in a new home but this are things that you need to address before they get worse and while your home is still under warranty. Please keep us posted on the outcome!

Which dehumidifier would you suggest that will not break the bank?

[energy_rater_La]

start with a stand alone dehumidifier.
if it works well, then upgrade to whole house dehumidifier.

I have a 15 SEER heat pump. air handler is variable speed.
this alone keeps RH in 55% range, in the summer.
for additional dehumidification I have Ultra aire 70H
this brings RH down to 45% in summer. and it is very
comfortable.

have you had a blower door test (& duct test) on your
home, or is the assumption that the house is tight due
to newness of build?

you should talk to Teddy Bear about whole house dehumidifiers.
he really knows his stuff.

ty duckman.

best of luck.

[teddy bear]

As general rule, reducing indoor %RH when the outdoor dew points are <55^F is most efficient done by increasing fresh air change. Do you have any fresh air ventilation? High indoor %RH during cool weather indicates a lack of fresh air change. Resulting in a buildup of moisture from the occupants and activities. Is there a crawlspace with uncovered earth or other sources of moisture?
Anyway, operate the bath fans 24/7 until humidity falls.
All occupied homes need a fresh air change in 4-5 hours when occupied. This is an important part of indoor air quality. During cold weather, the indoor dew point must be kept low enough to avoid condensation on any indoor surface. During the summer months allong with the fresh air change, keep the indoor moisture below 50%RH for comfort and to avoid mold and dust mites.
In your climate, a whole house ventilating dehumidifier is the most practical device to do all of this. Check out the Ultra-Aire 70H as minimal piece of equipment to do this. Check my past post for more info.
Regards TB

[energy_rater_La]

ahhh....there you are!

[clllclal]

As general rule, reducing indoor %RH when the outdoor dew points are <55^F is most efficient done by increasing fresh air change. Do you have any fresh air ventilation? High indoor %RH during cool weather indicates a lack of fresh air change. Resulting in a buildup of moisture from the occupants and activities. Is there a crawlspace with uncovered earth or other sources of moisture?
Anyway, operate the bath fans 24/7 until humidity falls.
All occupied homes need a fresh air change in 4-5 hours when occupied. This is an important part of indoor air quality. During cold weather, the indoor dew point must be kept low enough to avoid condensation on any indoor surface. During the summer months allong with the fresh air change, keep the indoor moisture below 50%RH for comfort and to avoid mold and dust mites.
In your climate, a whole house ventilating dehumidifier is the most practical device to do all of this. Check out the Ultra-Aire 70H as minimal piece of equipment to do this. Check my past post for more info.
Regards TB

Thanks for all the replies. As for the first question, I do not have any fresh air ventilation system. As for the second question, I am built on a slab, so no crawlspace or basement. Also, as I stated in my original post, it seems that when the heater kicks on, the humidity in the house shoots up all of a sudden. I just don't understand this. How much does the ultra-aire 70h cost and how much would it cost to have it installed? Thanks again, everyone.

Chad

[stvc]

Thanks for all the replies. As for the first question, I do not have any fresh air ventilation system. As for the second question, I am built on a slab, so no crawlspace or basement. Also, as I stated in my original post, it seems that when the heater kicks on, the humidity in the house shoots up all of a sudden. I just don't understand this. How much does the ultra-aire 70h cost and how much would it cost to have it installed? Thanks again, everyone.

Chad

Is there a humidifier installed in your system? I'm not that familiar with your climate but it seems to me that 70% is just too high to happen on it's own. I'm wondering if there is one it may not be properly wired or set and is running all the time. If not are there any other large sources of humidity like a hot tub?