Explanation of why this occurs?

[midolia]

Hi all,

I am, new to the Virtual environment and I have to submit a report on it for a building physics module at university. Could someone answer me two questions.

1) Why does the boiler/chiller peak heating and sens heating/cooling loads not change when I change the fuel type from natural gas to Biofuel? surely they have different efficiencies etc.

2) Why when I increase the glazing size on the south side of my office building does the peak heating and cooling loads increase for the boiler and chiller? I thought maybe it is due to increase U-value due to a larger window? but how can I justify making south facing windows larger in my design from this data??

Very much appreciated guys!!