Message Board Thread - "Heat Loss - Feedback Appreciated"

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Heat Loss - Feedback Appreciated Lex 12/15/2007
Hello all,

I would appreciate some feedback on the attached image as to the potential causes of the heat profile.

The image was taken at night (approx 23:00) with an ambient temperature of approximately 2degC and an internal temperature of approx 22degC. There was no wind and there had been no rain for over 24 hours (although fairly heavy rain experienced for a number of days previously).

The area in question is located at the South West corner of the building and there are a number of other buildings in close vicinity, with the same brick built structure.

The building is a ward in a hospital. The 2nd and 3rd storey windows are visible in this thermogram (I have another image showing the ground floor and will attach this later). The 3rd storey window is open.

I want to build up my 'building survey' experience and certainly do not proclaim to be an expert in this field but would like to put some initial thoughts to the mercy of this forum:

1) Could this purely be a result of air leakage from the open window (unlikely since the only open window is on the 3rd floor).
2) Could this be water penetration from a potential guttering issue at roof level (The way the warm area spreads out as you move down the building gives this indication).
3) Is this some sort of 'corner effect' since the area is well protected from the elements by adjacent buildings.

Feedback would be much appreciated.
Re:Heat Loss - Feedback Appreciated Lex 12/15/2007
Ground floor image...
Re:Heat Loss - Feedback Appreciated Doctir bob 12/17/2007
Corner effects are a reality and I believe part of the pattern is due to this. A gradient exists toward higher level indicating a larger sky view factor, hence larger cooling. But, if the interior temperatures are the same on each side of the corner, one would expect a more uniform pattern from side to side at the same level. Here, you have one side warmer than the other. Also, the brick surface is warmer than the closed lower window, a surprising condition.

You need to get more information as it looks suspicious. Why is the horizontal pipe a bit warmer than the vertical? What is the purpose of the horizontal pipe? Could there be a leak in the pipe? Your #2 is a strong possibility as well.
Re:Heat Loss - Feedback Appreciated Top Gun 12/17/2007
Doctir Bob provided great insights. I'd like to add that the geometry of this viewpoint with respect to the building suggests reflections. Considering the top image, the harsh gradient especially on the right-hand wall and an analogous feature on the opposite wall support this deduction. Also, near the top of the building, the thermal gradient is much sharper than that near the bottom of the image. One must consider the viewpoint incident angle to the surface is narrower at the top of the building than it is at the lower part of the building in the image. A somewhat "shiny" surface will be more reflective from a shallower viewpoint angle than at a steeper viewpoint angle. The true thermal gradient should be similar and nearly homogenous from top to bottom of this image (top).

The thermographer should have moved to his left to a position much closer to the left-hand wall and shot the right-hand wall to show the difference. That action would eliminate the possibility of reflection. It is also possible that the right-hand wall has a newer surface and "shinier" than the potentially older and dirtier left-hand wall which has a less significant reflection. Or the absence of warm windows on the right-hand wall presents less "heat" to reflect off the left-hand wall.

There is no mention of the nature of the brick surfaces in the images, and I've seen buildings with enamel or other glossy coatings on their brick which would appear "shiny".

Happy Holidays everyone!
Re:Heat Loss - Feedback Appreciated Inspectorpete 12/17/2007
Does anyone do heat loss surveys that do not include a blower door ETC?
Re:Heat Loss - Feedback Appreciated glassman 1/5/2008
There are more factors than pure visual that need to looked at. What is the construction of the wall (through section)?
What is being done on the other side of the wall?
as far as the pipe at the top is concerned and looking at the format of the pipe work it looks like sanitary outlets and there is a possibility that if it is a hospital the top outlet could be a hot water discharge which need to be identified.
Or this could be a simple case of heat retention on an outside skin where thet outer sections have cooled and the inner corner being well protected has not cooled at the same rate. Tere are many points that need to be addressed before a any anylasis is made. The picture is only the start.
Re:Heat Loss - Feedback Appreciated glassman 1/5/2008
Inspectorpete wrote:
yone do heat loss surveys that do not include a blower door ETC?
Just a quick reply to inspector pete
Yes I always start with a none pressured inspection as it can give a trurer picture.
Re:Heat Loss - Feedback Appreciated munster-ti 1/17/2008
Lex wrote:
floor image...
The left pipe seems to be a rain gutter(cold water),the right pipe is a drain for waste water (warm).when water is present it is warmer and emits heat into the building fabric.Inside the building you most likely have hot water and heating pipes along or in the wall servicing probably bathrooms(check plans).You might be looking at a combination of two or more heat sources.

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