Upwards tilted facade simulation results

Hello there,

I am running into some odd simulation results.
I am exploring the effects of a tilted facade on energy performance of a south-facing shoebox massing.
For some reason, when I tilt the facade upwards, the heating load goes up.


Would anyone know why this is happening? Is there a reasonable explanation for this or are my settings just wrong?

@kimtse1 ,

There could be a number of reasons for this and it’s hard to tell exactly which one without more information (the most important of which would be knowing what climate you are in and whether you’re in the north or south hemisphere). Thinking first of the most likely explanations, I would ask if the total amount of exposed exterior surface area increasing as you tilt the facade? If so, you could explain the increased heating through increased conduction through the facade.

Thanks for the super quick reply Chris!

The climate is North America (Calgary) and as it tilts upwards, it does stretch the south facade a bit more. Does this mean the shoebox is losing more heat than it is gaining through this surface during certain times?



@kimtse1 ,

Yes, looking at your diagram and knowing that the climate is pretty far north, I would venture a guess that the increased surface area is responsible for the increased heating. I imagine most of the heating is happening at night when there is no sun and envelope conduction dominates.

I took a closer look at the hourly data and you were right on the money!
Compared to a non-tilted massing, the upward tilting shoebox is creating more heating demand at night.

Couldn’t upload the GIF of the day graphs as is but here is a link to see the data.