: Usually range from 0.05 to 0.15 in. w.g. per 100 feet for commercial systems.
ESP=ΔPstraight+ΔPfittings+ΔPaccessoriesESP equals cap delta cap P sub straight end-sub plus cap delta cap P sub fittings end-sub plus cap delta cap P sub accessories end-sub ΔPstraightcap delta cap P sub straight end-sub = Linear friction losses in straight duct sections. ΔPfittingscap delta cap P sub fittings end-sub esp calculation for duct
$$ESP = (P_supply + P_return) + P_accessories$$ : Usually range from 0
0.08 to 0.12 in. w.g. per 100 ft of duct (supply side). esp calculation for duct