Hi Nnaemeka,
Does your annual running cost for the air conditioner include the cost of electricity? If it does, then yes, you would be double-counting the cost of electricity in your model if you added it into the Demand Cost variable.
Can you clarify what you mean by "fueling cost for transportation"? Do you mean the cost of the fuel? Or the cost of the fueling station infrastructure? Or both? Again, if you include both the cost of fuels consumed using a) the Demand Cost variable and also b) inside a cost variable within the Resources branches (or if you include costs within the transformation module which produces the transportation fuel), then you are effectively including the same information twice in the model, and LEAP's cost-benefit accounting will double-count these costs.
I think that rather than trying to answer these cost questions on a case-by-case basis, it would be most helpful for you to thoroughly review some of the help files on cost-benefit accounting in LEAP. I'd recommend starting here:
https://www.energycommunity.org/Help/Concepts/Transformation_Cost_Calculations.htm
https://www.energycommunity.org/Help/Concepts/Social_Cost-Benefit_Analysis.htm
https://www.energycommunity.org/Help/Resources/Resource_Costs.htm
https://www.energycommunity.org/Help/Results_Categories/Costs.htm
In particular, you should consider where in your model it is appropriate to set your cost-benefit "boundary", which is briefly described
here.
Hope this is useful,
Taylor