Sealing up a Leaky Room

Reply

  #1  
Old 11-02-20, 10:08 AM
P
Member
Thread Starter
Join Date: Feb 2019
Location: United States
Posts: 149
Received 3 Votes on 3 Posts
Sealing up a Leaky Room

The previous owners of my house added a single room 300 sqft extension off of the side. Its on slab and its conditioned by ac and a hydroair system that is beyond overkill for the small space. Now, entering my third winter in this house (and being home more often), I am ready to tackle the leaky air that keeps the room so cold.

Some of the facts:
  • The blower is in an unconditioned utility closet that shares a wall with the room and is accessible from the outside. I have sealed up every crack of that closet and ensured the duct work that is exposed in the closet is insulated fully. The duct work goes up into the ceiling, which I cannot access.
  • A master bath was installed above this extension room, it is also pretty chilly in the winter.
  • On the coldest days, will need to cycle every hour to keep temperature (with a 3 degree delta set on the stat)
  • three 3x12" supplies in the ceiling, one larger return in wall near ceiling (maybe 10x20")
  • The room is currently 62F. Outside is currently 45F. I borrowed a FLIR gun and found several spots that are 50F along the baseboards, in corners, and around the sliding door. The registers and return all read about 60F.
Based on the FLIR readings, it doesn't seem like cold air is leaking in (maybe I need to remeasure on a colder day) from the HVAC ducts..?? Do the 50F spots along the baseboard maybe explain it? If so, any suggestions on sealing them up?
 
  #2  
Old 11-02-20, 12:23 PM
P
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 24,457
Received 752 Votes on 691 Posts
How is the room insulated? It sounds like you've been good about tackling air leaks but at some point it comes down to what's in the walls. Top plates, sill plates, studs & headers will always show cold (in winter) because wood is a poor insulator. Any areas where a lot of framing comes together like corners also tends to show cold because there is a lot of wood and not much space for insulation.
 
  #3  
Old 11-03-20, 08:00 AM
P
Member
Thread Starter
Join Date: Feb 2019
Location: United States
Posts: 149
Received 3 Votes on 3 Posts
Thanks, PD. Without ripping open some sheetrock to check the rating, all I can say is it does have vapor barrier and fiber glass insulation.

I definitely see leaks along the baseboards, the seems of the sliding door, and in corners (at those wood-wood junctions you mentioned). Currently my baseboards are flat four inch plank with trim on top. I am thinking of calking between the plank and the hardware floor and, if the calk shows, to add a piece of quarter round trim along the bottom. Short of ripping up and redoing the baseboard, I don't have any other ideas?

Wall surfaces and recessed lighting all look pretty good on the FLIR. I am wondering tho, are there subtle thinks I should look for with the FLIR image? Is a cold leak obvious or could it be a bit more subtly and still be a problem?
 
  #4  
Old 11-03-20, 08:35 AM
P
Member
Thread Starter
Join Date: Feb 2019
Location: United States
Posts: 149
Received 3 Votes on 3 Posts
here are some FLIR shots. The room is currently 64 degrees. Outside is 47F, so not too cold and little to no wind outside. Leaks aren't awful but I still think they are something to fix?


 
  #5  
Old 11-03-20, 11:28 AM
B
Member
Join Date: Oct 2008
Location: New England
Posts: 10,524
Received 37 Votes on 34 Posts
Your approximate location so we will know your climate.

Use all exhaust fans to enhance air leakage and convert all leakage to infiltration.

Without the fan some leaks act as exhaust which is difficult to see with IR. Mid zone leaks are neutral so neither exhaust or intake, thus no indication on IR.

Type of FLIR camera?

Bud
 
  #6  
Old 11-03-20, 11:40 AM
B
Member
Join Date: Oct 2008
Location: New England
Posts: 10,524
Received 37 Votes on 34 Posts
Busy so above post was just notes as I read the thread.
Being on a slab the exterior edge of that slab will be like an ice cube when really cold outside and that cold conducts inward 3 or 4 feet making for very cold floors. Those cold edges can be protected with rigid foam board but probably better for next spring.

Using exhaust air as mentioned above will give you totally different pictures and current temps are just fine. That camera can detect very small temp differences.

With the exhaust fans going (kitchen, bath,dryer,, or window fans you will see a lot of infiltration. Hope you still gave the camera.

Bud
 
  #7  
Old 11-03-20, 12:57 PM
P
Member
Thread Starter
Join Date: Feb 2019
Location: United States
Posts: 149
Received 3 Votes on 3 Posts
Thanks, Bud. I still have the camera. Its on "borrow" until someone at work yells at me. lol The model number in the settings menu reads "E5 1.2L" but the model number printed on the side of the camera is "FLIR-E63900". There aren't many settings that can be adjusted on the camera but let me know if I should do so; its my first time using one.

Good thinking with the exhaust fans. I will turn on the two bathroom exhaust fans upstairs and the kitchen exhaust fan. I will give that a try later tonight when I get free and when it cools down a bit outside.

I am located along the shoreline in Connecticut.
 
  #8  
Old 11-03-20, 01:31 PM
B
Member
Join Date: Oct 2008
Location: New England
Posts: 10,524
Received 37 Votes on 34 Posts
Nice camera. Those 3 fans should be sufficient to take the whole house negative. I use a blower door fan and turn it down so I don't freeze everyone out. You will see cavities getting cold and colder with time.

Recessed ceiling lights, attic access, and baseboards are key places as they all provide direct paths to outside temps. Which ones you can fix becomes another problem.

Also note the floor temperatures around the perimeter to see if the cold is conducting inward. And go outside to look at the edge of that slab.

I can also reverse the direction of my fan so I can go outside and see hot spots where warm air is coming out. You would need a couple of window fans if they are strong enough.

Bud
 
  #9  
Old 11-04-20, 09:10 AM
P
Member
Thread Starter
Join Date: Feb 2019
Location: United States
Posts: 149
Received 3 Votes on 3 Posts
Thanks for feedback. I didn't get a chance to check last night but will probably get to it this weekend. I will report back then!
 
Bud9051 voted this post useful.
  #10  
Old 11-11-20, 09:43 AM
P
Member
Thread Starter
Join Date: Feb 2019
Location: United States
Posts: 149
Received 3 Votes on 3 Posts
well its still 70F here. I am waiting for the indoor/outdoor differential to get a bit larger before imaging again.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: