Dear Everyone,

I am writting to enquire about ASHRAE 90.1-2010 Mandatory Provision which regards to Optimum Start Controls. It states that heating&cooling air distribution systems shall have control algorithm. 

Typically air handling unit which terminal conditioning system is used in our country. 

My questions are:

1. Does that requirement regards to terminal unit system - fan coil where it may be hard to estimate capacity of 5000L/s or makeup air system, or only for fresh air (rooftop) system which is not our case.

2. I understand that algorithm should evaluate the warmup time based on actual temperature difference. So for each day for different actual indoor condition warmup time must be evaluated separately. Am I right?

3. Usually warmup time is set as fixed with fixed setback temperature. In that case this requirement is not meet, right?

Best Regards