Go Back   DIY Chatroom Home Improvement Forum > DIY Repair > General DIY Discussions

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 12-12-2011, 06:54 PM   #1
Member
 
Join Date: Jun 2011
Location: Plattsburgh, NY
Posts: 243
Rewards Points: 154
Default

Moisture in Unheated Room


I have a sunroom on the side of my house that's designed for year-round use. It has an electric baseboard heater and new vinyl double-hung windows. The former owners used it as an office and play area for their kids. It's off the living room through sliding glass doors. I don't have any use for it, so I left the heat off and shut the windows. I noticed there's no insulation above the plywood ceiling and electric heat is expensive.

On the cold mornings now, the room is covered in moisture. The ceiling is dripping with water and there's enough condensation pooling in the windows that it freezes into a little ice. The only way I seem to be able to stop this is turning on the heater (which heats it up to about 70 even on the lowest setting) or leaving the glass doors open.

I hate to waste money on heating a space I'm not using, but I don't want the moisture to wreck anything. Any ideas?

matt151617 is offline   Reply With Quote
Old 12-12-2011, 09:07 PM   #2
Member
 
jburd964's Avatar
 
Join Date: May 2009
Location: Louisiana
Posts: 218
Rewards Points: 150
Default

Moisture in Unheated Room


Open are crack one of the outside windows and leave it, the cold outside air should remove the moisture from your room. I would suggest you inspect the connecting walls, windows and attic looking for heat loss into sunroom. If its that cold where your at, a non heated room should be a lot drier. Heat contacting cold extracts moisture.

I'm not a professional., But I did stay at Holiday Inn Express last night.

__________________
Gun control isn't about guns, IT'S ABOUT CONTROL.
jburd964 is offline   Reply With Quote
Old 12-12-2011, 09:36 PM   #3
Retired from the grind
 
gregzoll's Avatar
 
Join Date: Dec 2006
Location: Midwest - Central Illinois
Posts: 14,340
Rewards Points: 2,342
Default

Moisture in Unheated Room


Place a dehumidifier in the space. If you are getting that much moisture in the space, no telling what it is like behind the wall covering. How warm is this space, and you really need to find out why it is behaving like it is, which it shouldn't if unheated. It should be just like a garage that is insulated, but not heated in the Winter. It should not have any condensation in it.

Get a humidistat to find out how much humidity is in the air vs. ambient air temp.
__________________
Ren: Now listen, Cadet. I've got a job for you. See this button? Ren: Don't touch it! It's the History Eraser button, you fool! Stimpy: So what'll happen? Ren: That's just it. We don't know. Maybe something bad, maybe something good. I guess we'll never know, 'cause you're going to guard it. You won't touch it, will you?
gregzoll is offline   Reply With Quote
Old 12-12-2011, 09:41 PM   #4
Member
 
Join Date: Dec 2008
Location: Fairbanks, AK
Posts: 1,847
Rewards Points: 1,000
Default

Moisture in Unheated Room


Quote:
Originally Posted by jburd964 View Post
Heat contacting cold extracts moisture.
MOISTURE, I am sure you meant, contacting cold results in condensation.
OP: Is there any way to better insulate and air seal between the heated and non-heated room? That would sure help, if at all possible. Then you could leave a window wide open and PROBABLY be OK. (That depends on how much air and moisture are leaking out there, of course.)
jklingel is offline   Reply With Quote
Old 12-12-2011, 09:52 PM   #5
Newbie
 
Join Date: Dec 2011
Posts: 4
Rewards Points: 10
Default

Moisture in Unheated Room


You need to make sure you have a vapor barrier material installed, especially under the floor. Vapor barrier paint is available as well. Also put down r21 or greater insulation under the floor and r49 or greater in the ceiling. Not sure if you said the walls were already insulated. The warmer moist air of that room is condensing when it hits the cold walls.
Blacek is offline   Reply With Quote
Old 12-12-2011, 10:59 PM   #6
Member
 
Join Date: Jun 2011
Location: Plattsburgh, NY
Posts: 243
Rewards Points: 154
Default

Moisture in Unheated Room


I am in the process of adding insulation above the ceiling. There's no foundation underneath the room so it would be almost impossible to insulate from below.

I have a dehumidifier in the basement that doesn't really need to run in the winter, but I was under the assumption a dehumidifier doesn't work properly when the temperature gets under 40 degrees.

There's no way to insulate between rooms better without sealing up the glass doors. By leaving the door open a little and letting some of the house's heat out there, it keeps it pretty dry except a little condensation on the windows.

Inspected the walls and everything appears in order. Only difference I noticed is the sunroom has plywood ceilings with no insulation as opposed to drywall ceilings with insulation in the rest of the house.
matt151617 is offline   Reply With Quote
Old 12-12-2011, 11:27 PM   #7
Newbie
 
Join Date: Dec 2011
Posts: 4
Rewards Points: 10
Default

Moisture in Unheated Room


If possible, try to at least insulate the ceiling, r49 or better. That would probably help a bit. Maybe you could have some insulation foam sprayed under the floor? Dont know too much about that stuff, so do a little research first about what it is made of and any possible safety issues (is it flammable, etc). If the foam seems ok, maybe it will double as a vapor barrier too.
Blacek is offline   Reply With Quote
Old 12-13-2011, 12:03 AM   #8
Registered User
 
Join Date: Mar 2009
Posts: 9,967
Rewards Points: 2,000
Default

Moisture in Unheated Room


You need heat after the sun goes down. As you said open the sliding door and live with the results. Or, insulating night-time shutters (R-5-10) on the cold glazing (R-2-5)- my second choice, or, install some thermal mass; http://www.buildgreen.ca/2008/09/an-...-thermal-mass/
Water barrels would work well, let me know further...

Gary
__________________
If any ads are present in my answer above, I do not condone/support/use the product or services listed, they are there against my permission.
Gary in WA is offline   Reply With Quote
Old 12-13-2011, 03:30 AM   #9
Member
 
Join Date: Sep 2011
Posts: 166
Rewards Points: 150
Default

Moisture in Unheated Room


I see the problem resulting from two things. One is, the room not being used at all and not heated means the walls and ceilings are extremely cold. Secondly any moist air that enters the room by someone opening the glass doors if only for an instant, will result in condensation.

Would you believe up to a pint of water condenses from mosit air every hour for a medium size space. Just breating in a cold room will produce droplets on cold ceilings over a period (like if someone sleeps in the room overnight).
  1. To address these two conditions, are you able to insulate the walls and ceiling to stop loss of heat and so you can maintain their surface temperature.
  2. Are you able to seal the room from moist air?
If the answer is no, you need to allow the space to reach room temperature as for the rest of the house. Can you use a different form of heater to an electric radiator system? Surely in such a cold climate, there was provision for house heating, like a fireplace in each room, slow combustion heater or possibly gas. People also install oil heaters, hot water radiators and such like. There is always a source of heat, or people simply woudn't live there.

Even eskimos are snug in their igloos (ice is a good insulator) and light a central fire.

If you have no other choice but electricity, your best option is a reverse cycle A/C unit. with split diffuser. These units use 2.5 kW (watts) of electricity to produce approximately 3-1/2 times the heat out put that is around 8 kW.
That's like running 8 bar radiators for the price of 2.

The larger your house, the bigger the unit required. An 8 kW unit will just do 18-20 squares. It will also give you 7.5 kW of cooling on a hot day. Most importantly, it will remove 3 pints of water from the air every hour its on.

Today's units have inverters which ramp up or down depending on conditions. When your house is warm, the units work very little and consume little electricity. This depends how quickly your house loses heat, or simply how well its insulated.

Hope you understood the simple physics at play here.
Cheers from Joe in Oz
JoJo-Arch is offline   Reply With Quote
Old 12-13-2011, 03:36 AM   #10
Member
 
Join Date: Sep 2011
Posts: 166
Rewards Points: 150
Default

Moisture in Unheated Room


I see the problem resulting from two things. One is, the room not being used at all and not heated means the walls and ceilings are extremely cold. Secondly any moist air that enters the room by someone opening the glass doors if only for an instant, will result in condensation.

Would you believe up to a pint of water condenses from mosit air every hour for a medium size space. Just breating in a cold room will produce droplets on cold ceilings over a period (like if someone sleeps in the room overnight).
  1. To address these two conditions, are you able to insulate the walls and ceiling to stop loss of heat and so you can maintain their surface temperature.
  2. Are you able to seal the room from moist air?
If the answer is no, you need to allow the space to reach room temperature as for the rest of the house. Can you use a different form of heater to an electric radiator system? Surely in such a cold climate, there was provision for house heating, like a fireplace in each room, slow combustion heater or possibly gas. People also install oil heaters, hot water radiators and such like. There is always a source of heat, or people simply woudn't live there.

Even eskimos are snug in their igloos (ice is a good insulator) and light a central fire.

If you have no other choice but electricity, your best option is a reverse cycle A/C unit. with split diffuser. These units use 2.5 kW (watts) of electricity to produce approximately 3-1/2 times the heat out put that is around 8 kW.
That's like running 8 bar radiators for the price of 2.

The larger your house, the bigger the unit required. An 8 kW unit will just do 18-20 squares. It will also give you 7.5 kW of cooling on a hot day. Most importantly, it will remove 3 pints of water from the air every hour its on.

Today's units have inverters which ramp up or down depending on conditions. When your house is warm, the units work very little and consume little electricity. This depends how quickly your house loses heat, or simply how well its insulated.

Hope you understood the simple physics at play here.
Cheers from Joe in Oz
JoJo-Arch is offline   Reply With Quote
Old 12-13-2011, 06:28 AM   #11
Member
 
Join Date: Nov 2011
Location: Hartfield VA
Posts: 27,518
Rewards Points: 4,152
Default

Moisture in Unheated Room


I think Jo Jo is talking about a mini split unit.
And he's right it works great and cost very little to run. I live in a tiny one bedroom house and I went from gas heat that was costing over $150.00 a month to a small mini split and my total electric bill is about $40.00 in the winter and summer and I have not bought gas in 2, years since I put it in.
(I use gas for my cooking stove.)
The lowest temp. I can set mine is 58 deg.
joecaption is offline   Reply With Quote
Old 12-13-2011, 10:22 AM   #12
Member
 
Join Date: Jun 2011
Location: Plattsburgh, NY
Posts: 243
Rewards Points: 154
Default

Moisture in Unheated Room


Thanks for the info. I've been in the process of putting R-30 above it, it's just very difficult to get to. The rest of the house is also under-insulated. The sunroom was an addition at some point; the wiring is all new and there's no foundation under it. The rest of the house is heated with oil hot water so there's no hot water radiator out there.

Here's the humidity readings I got:

Inside the house, 62 degrees, 56% RH
Outside the house, 30 degrees, 68% RH
Inside the sunroom, 46 degrees, 88% RH

It sounds like I'll just leave the glass doors open and get the insulation down asap. The house air seems to provide enough warm air to limit the condensation to only the windows and not enough to cause any pooling of water.
matt151617 is offline   Reply With Quote
Old 12-13-2011, 11:52 AM   #13
Member
 
ccarlisle's Avatar
 
Join Date: Jul 2008
Location: Montreal, Quebec, Canada
Posts: 1,889
Rewards Points: 1,000
Default

Moisture in Unheated Room


I'm interested: what do you mean exactly by the room "has no foundation"? Do you mean it is sitting directly on the ground?

I am sure that, by now, it has occurred to you that surpressing the source of heat in that room isn't really a viable option as it is the heat that controls - or keeps in check - the moisture level. So, where is that excess moisture coming from?

It seems that the room was built as a three-season room insulation-wise - but was forced into being a four-season room with the addition of the electric heater...as in trying tp get the best of both worlds. In our climate, that's almost impossible. You either build the room to be a four-season room with the proper level of insulation etc - OR you must be prepared to heat an under-insulated structure. By adding insulation on the roof part, you're about to lower your heating costs by a bit - but you'll still need to heat it. And unless you fix the moisture issue, you'll also still need to heat it, no matter what insulation level you have in there now - or later...

The heat will warm the interior elements and keep the ice-formation from happening; it will reduce the RH too at the same time. But you're stuck, IMO, with either having to heat it or dehumidify it one or the other.
__________________
“The average American woman is about 25 pounds heavier than she was in 1960...Recognizing obesity as a disease will help change the way the medical community tackles this complex issue that affects approximately 1 in 3 Americans,”
ccarlisle is offline   Reply With Quote
Old 12-13-2011, 12:22 PM   #14
Member
 
Join Date: Jun 2011
Location: Plattsburgh, NY
Posts: 243
Rewards Points: 154
Default

Moisture in Unheated Room


Yes, as in there's no basement under that part where there is in the rest of the house. I'll try and see if the walls are insulated, but it probably doesn't matter much, since most of the room is windows.

I noticed on my electric bill history the former owners were using 4 times the electricity I use now... probably due to the fact they were heating an uninsulated room...

Last edited by matt151617; 12-13-2011 at 12:24 PM.
matt151617 is offline   Reply With Quote
Old 12-13-2011, 12:57 PM   #15
Member
 
ccarlisle's Avatar
 
Join Date: Jul 2008
Location: Montreal, Quebec, Canada
Posts: 1,889
Rewards Points: 1,000
Default

Moisture in Unheated Room


Ah-ha, I see; ideally, there would have been a vapour barrier right on the ground (underneath the room) and ventilation at a minimum. But you may have neither...hence the source of humidity.

I don't think there's much point in checking for insulation on the walls; it would make little sense if there was, and probably there isn't. Either way, the moisture is coming from under there - and that's your #1 issue at this point.

Yes, moisture could be coming from the inside every time you crack the doors, but my money is on the constant, cold-temperature-driven release of moisture from the ground up. There is pleanty of advice on crawl space insulation around, but most of it assumes you have access to the area underneath...if you don't have that access, I'm afraid your choices will be limited to keeping on a minimal amount of heat and ventilation to keep the condensation at bay.

__________________
“The average American woman is about 25 pounds heavier than she was in 1960...Recognizing obesity as a disease will help change the way the medical community tackles this complex issue that affects approximately 1 in 3 Americans,”
ccarlisle is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Insulating a cold/well room? Lynch Building & Construction 23 07-25-2014 03:49 PM
Cleaning brush StevenH Painting 19 02-06-2011 12:13 AM
Basement Moisture, what's this? bergerdude Building & Construction 1 06-11-2010 02:27 PM
Vents from boiler room RammsteinNicCage HVAC 3 03-11-2009 08:28 PM
Moisture in Concrete LBlack Flooring 9 10-31-2008 08:24 PM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.