Showing posts with label concrete wall. Show all posts
Showing posts with label concrete wall. Show all posts

16 August 2016

Where does the heat go?

We have a relatively new (2011) timber framed house.  It was built to comply fully with the current New Zealand Building Code and has glass fibre wall and ceiling insulation and double glazed aluminium joinery - not particularly noteworthy when compared with colder parts of the world but quite suitable for New Zealand's temperate climate.  

Here were the outside and inside temperatures last night at about 10pm:



Our only source of heating is a 20kW wood burner, which we light on most winter evenings for about four hours.

Under the concrete floor I used 50mm of black polystyrene, which is slightly warmer than the standard white variety.

When designing the house I was aware that it was also good practice to insulate the vertical face of the perimeter foundations, however this is difficult to construct for a few reasons and is not often done in New Zealand.

Last night I used an infrared camera attachment on my phone to take some photos.



Here you can clearly see heat radiating from the non-thermally broken door and window frames, but also from the small exposed strip of foundation wall.



From the inside of the house you can also clearly see heat escaping around the perimeter of the floor.

The path for the heat loss is as follows:



This issue is going to be addressed in the near future.  We have a very comfortable home, but there is always room for improvement.

Incidentally, we have a concrete wall behind our wood burner which I designed as a form of heat storage.  This slowly heats up from the fire and then radiates the heat after the fire goes out.  This infrared photo was taken the next morning, about twelve hours after the embers had died.  The wall and tiled hearth are still radiating heat into the room despite the wood burner being cold.