I have installed systems in hangers. Co Ray Vac systems work GREAT. 400 to 500 foot systems with zoning that give you great control. The VAC Pump hangs on exterior wall and all piping runs to it. 20 burners and 6 zones on last system.
As for Efficient I think people keep misunderstanding this...
The total building heat loss would still be used at a given delta T. Local outdoor design temp / required indoor design temp. I have had the best results with air rotation units even if you are not trying to heat at floor level. This is still the best way to handle keeping sprinklers from...
