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Mike Natal Posted: Sep 24, 2008 08:10 AM	Moisture,Mold and High Electric Bills. Please Help! Moisture.Mold and High Electic bills. Please Help! -------------------------------------------------------------------------------- 1)I have exquast fans in all bathrooms venting outside. 2)My cook top hood is vented directly outside. My moisture.humidity/mold problems do not exist in my home living space that is air conditioned.That relative humidity is aroud 45 to 50% which is inside the normal range. Keep in mind I live in Louisiana where the outside air is humid as heck. I also live on the water where theres a brisk wind most of the time. My problem lies in my attic! Thats where the moisture and mold is. The humidity is on averge 75 to 82% in my attic at any given time. My air conditioned space is about 3000SF. I have two three ton heat pumps, one for the bedroom areas and the other for the living and kitchen areas. My main question is, what different items should my AC man have done to the inside air handlers since I enclosed my rafters and walls with open cell spray foam vs normal batt insulation?? He did down size mt units by the way. I told my brother I need a thicker per inch average and the attic needs to be completely enclosed are the air seeping in will cause all metal items to draw the moisture to them and sweating will occur all over. I did a negative air test which verified what I just said. My avg. thickness of .5lb closed cell in the rafters is about 2-1/2" thick. My walls are sprayed with 2" of closed cell. What is the main solutin to the air thats in the attic? I was told no to fresh air or make up air being brought in from outside. I was told no to air conditioning my attic. What is the correct thing to do different to the air handlers in the attic with the rafters haveing the foam? Final problem, My electric bill Is $890.00 this past month. Where my neighbors house which is just like mine is $550.00 Please Help! Thanks, Mike N
Jim Coler Posted: Sep 24, 2008 09:00 AM	Check my reply on the other post from your brother - It also sounds like your HVAC system is too large and is short cycling. This will drive electric bill up and not run long enough to control the RH.
Lane Hogstad Posted: Sep 24, 2008 09:25 AM	What temp is your attic during the day?
Mike Natal Posted: Sep 24, 2008 09:32 AM	Between 72 and 76 degrees.
Jim Coler Posted: Sep 24, 2008 11:02 PM	Based on 76 degrees air temp and 82% RH, you may see condensation on surfaces which are 72 degrees or below. Where is the moisture coming from? What is the RH and Temp outside - dayand night - highs and lows? It seems you just have too much moisture in the air and you need to figure out where it's coming from. Also if you can let us know what it's condensing on, it might help.
William Gibson Posted: Sep 25, 2008 07:21 AM	Mike - What is the current state in your basement. Is it a dry area or damp. What is there for flooring, insulation, etc.
William Gibson Posted: Sep 25, 2008 07:21 AM	Mike - What is the current state in your basement. Is it a dry area or damp. What is there for flooring, insulation, etc.
Mike Natal Posted: Sep 25, 2008 08:31 AM	This is not a basement, its my attic space under the roof.We dont have basements in louisiana. No, my roof rafters are wood 2x8 not metal. The sweating is occuring on all the metal duct boxs, air handlers, pvc pipes. I think once I respray the attic with 2" more of .5 lb open cell and seal up all the small areas that are allowing outside air in I will be fine and the moisture and mold problems will go away. What do ya'll think?
Mike Natal Posted: Sep 25, 2008 08:39 AM	I only run one unit at a time. At night i run the 3 ton for all the bedrooms and put the other unit on 79 degrees. During the day, I only have the living and kitchen 3 ton on and have my bed room set at 79 degrees. Does this help you figure it out?
Jim Coler Posted: Sep 25, 2008 05:12 PM	He was asking about the basement to try and figure out where the excess moisture is coming from. Basements and/or crawlspaces are the primary source of excessive moisture in a home. Is this built on a crawlspace or slab? What do you have for a vapor barrier between the grouond and the floor? What are the exterior temperatures (highs and lows) and RH when you see the condensation issues?
SprayFoamSupply.com Posted: Sep 27, 2008 06:13 PM	Mike, You said, "My avg. thickness of .5lb closed cell in the rafters is about 2-1/2" thick. My walls are sprayed with 2" of closed cell." .5lb foam foam is not closed cell, it is open cell. If you only have 2 1/2" of open cell in your rafters, that is the problem. It is not enough insulation for any climate. Please clarify if you have open or closed cell foam. George
Mike Natal Posted: Sep 28, 2008 07:30 PM	Its open cell, My bad. It ranges from 1/2" thick to 5" thick. Shouldnt it be at least a min. of 5" thick? Which would give me 15 or 16 R-value. My spray contracter is coming this week to spray it correctly. Do u then think it will correct the moisture problems?
Jim Coler Posted: Sep 28, 2008 10:54 PM	Mike, There are still a lot of questions in this thread which have not been answered by you and they can play a significant role in whether this will correct your problem or not. The crawlspace/slab vapor barrier, exterior temps (highs/lows), and where the condensation is occuring is all important and needed to help further the diagnosis.
Greg Pruitt Posted: Nov 01, 2008 04:47 PM	The answer seems simple, you said the roof deck was not sprayed properly as the contractor was having to come back out to spray areas he missed. I would recommend that when you look up you see nothing but foam. the top plate must be srayed, and biscuits or some other method used to where that the soffit is not open. You are doing a closed cell attic assembly....It must be closed! Outside moisture laden air cannot come into this system. Next you need to retink your aircondintioning. Contractors say they are downsizing, and they do, but many of them think they are right when they down size 10-20 %. ON a three thousand sq foot house in east Texas, most contractor would use 6 tons for fiberglass. We would reccommend 3.5 tons....and it works! everytime. If you really think you need more toannage, go to a 2 stage compressor, and a variable speed fan, and maybe a zone. YOu will not need the extra tonnage, but you will have a better more energy efficient system. this problem can be fixed. If your foam contractor and HVAC guy can't fix it, e-mail me. gregpruitt55@hughes.net. The sky is not falling, but some attention needs to be paid to the processof considering the home as a system. YOu can't just do one thing to it and expect results. Foam and A/C go hand in hand. I hope this helped.

Author

Comments

Mike Natal

Posted: Sep 24, 2008 08:10 AM

Moisture,Mold and High Electric Bills. Please Help!

Moisture.Mold and High Electic bills. Please Help!
--------------------------------------------------------------------------------
1)I have exquast fans in all bathrooms venting outside.
2)My cook top hood is vented directly outside.
My moisture.humidity/mold problems do not exist in my home living space that is air conditioned.That relative humidity is aroud 45 to 50% which is inside the normal range. Keep in mind I live in Louisiana where the outside air is humid as heck. I also live on the water where theres a brisk wind most of the time.
My problem lies in my attic! Thats where the moisture and mold is. The humidity is on averge 75 to 82% in my attic at any given time. My air conditioned space is about 3000SF. I have two three ton heat pumps, one for the bedroom areas and the other for the living and kitchen areas. My main question is, what different items should my AC man have done to the inside air handlers since I enclosed my rafters and walls with open cell spray foam vs normal batt insulation?? He did down size mt units by the way. I told my brother I need a thicker per inch average and the attic needs to be completely enclosed are the air seeping in will cause all metal items to draw the moisture to them and sweating will occur all over. I did a negative air test which verified what I just said.

My avg. thickness of .5lb closed cell in the rafters is about 2-1/2" thick. My walls are sprayed with 2" of closed cell.

What is the main solutin to the air thats in the attic? I was told no to fresh air or make up air being brought in from outside. I was told no to air conditioning my attic. What is the correct thing to do different to the air handlers in the attic with the rafters haveing the foam?
Final problem, My electric bill Is $890.00 this past month. Where my neighbors house which is just like mine is $550.00
Please Help!

Thanks,
Mike N

Jim Coler

Posted: Sep 24, 2008 09:00 AM

Check my reply on the other post from your brother - It also sounds like your HVAC system is too large and is short cycling. This will drive electric bill up and not run long enough to control the RH.

Lane Hogstad

Posted: Sep 24, 2008 09:25 AM

What temp is your attic during the day?

Mike Natal

Posted: Sep 24, 2008 09:32 AM

Between 72 and 76 degrees.

Jim Coler

Posted: Sep 24, 2008 11:02 PM

Based on 76 degrees air temp and 82% RH, you may see condensation on surfaces which are 72 degrees or below.

Where is the moisture coming from? What is the RH and Temp outside - dayand night - highs and lows?

It seems you just have too much moisture in the air and you need to figure out where it's coming from. Also if you can let us know what it's condensing on, it might help.

William Gibson

Posted: Sep 25, 2008 07:21 AM

Mike -
What is the current state in your basement. Is it a dry area or damp. What is there for flooring, insulation, etc.

William Gibson

Posted: Sep 25, 2008 07:21 AM

Mike -
What is the current state in your basement. Is it a dry area or damp. What is there for flooring, insulation, etc.

Mike Natal

Posted: Sep 25, 2008 08:31 AM

This is not a basement, its my attic space under the roof.We dont have basements in louisiana.

No, my roof rafters are wood 2x8 not metal. The sweating is occuring on all the metal duct boxs, air handlers, pvc pipes.

I think once I respray the attic with 2" more of .5 lb open cell and seal up all the small areas that are allowing outside air in I will be fine and the moisture and mold problems will go away. What do ya'll think?

Mike Natal

Posted: Sep 25, 2008 08:39 AM

I only run one unit at a time.

At night i run the 3 ton for all the bedrooms and put the other unit on 79 degrees.
During the day, I only have the living and kitchen 3 ton on and have my bed room set at 79 degrees. Does this help you figure it out?

Jim Coler

Posted: Sep 25, 2008 05:12 PM

He was asking about the basement to try and figure out where the excess moisture is coming from. Basements and/or crawlspaces are the primary source of excessive moisture in a home. Is this built on a crawlspace or slab? What do you have for a vapor barrier between the grouond and the floor?

What are the exterior temperatures (highs and lows) and RH when you see the condensation issues?

SprayFoamSupply.com

Posted: Sep 27, 2008 06:13 PM

Mike,

You said, "My avg. thickness of .5lb closed cell in the rafters is about 2-1/2" thick. My walls are sprayed with 2" of closed cell."

.5lb foam foam is not closed cell, it is open cell. If you only have 2 1/2" of open cell in your rafters, that is the problem. It is not enough insulation for any climate. Please clarify if you have open or closed cell foam.

George

Mike Natal

Posted: Sep 28, 2008 07:30 PM

Its open cell, My bad. It ranges from 1/2" thick to 5" thick. Shouldnt it be at least a min. of 5" thick? Which would give me 15 or 16 R-value.
My spray contracter is coming this week to spray it correctly. Do u then think it will correct the moisture problems?

Jim Coler

Posted: Sep 28, 2008 10:54 PM

Mike,
There are still a lot of questions in this thread which have not been answered by you and they can play a significant role in whether this will correct your problem or not. The crawlspace/slab vapor barrier, exterior temps (highs/lows), and where the condensation is occuring is all important and needed to help further the diagnosis.

Greg Pruitt

Posted: Nov 01, 2008 04:47 PM

The answer seems simple, you said the roof deck was not sprayed properly as the contractor was having to come back out to spray areas he missed. I would recommend that when you look up you see nothing but foam. the top plate must be srayed, and biscuits or some other method used to where that the soffit is not open. You are doing a closed cell attic assembly....It must be closed! Outside moisture laden air cannot come into this system. Next you need to retink your aircondintioning. Contractors say they are downsizing, and they do, but many of them think they are right when they down size 10-20 %. ON a three thousand sq foot house in east Texas, most contractor would use 6 tons for fiberglass. We would reccommend 3.5 tons....and it works! everytime. If you really think you need more toannage, go to a 2 stage compressor, and a variable speed fan, and maybe a zone. YOu will not need the extra tonnage, but you will have a better more energy efficient system. this problem can be fixed. If your foam contractor and HVAC guy can't fix it, e-mail me. gregpruitt55@hughes.net. The sky is not falling, but some attention needs to be paid to the processof considering the home as a system. YOu can't just do one thing to it and expect results. Foam and A/C go hand in hand. I hope this helped.

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