Boiler replacement-pickup factor

E. Overton

In calculating EDR for boiler replacement for a one-pipe steam system in a 1910, two story house (5000+ Sq. Ft.with 12 ft. ceilings)), should the second floor risers be measured where they are exposed on the first floor (floor to ceiling/uninsulated) and included in the EDR? I have calculated boiler size by converting radiator EDR to MBH using a 1.50 pickup factor according recommendations in Dan's book, but he also points out that there may be unusual piping sitituations that need to be considered. Should exposed risers be a concern? All original radiators are in place and the insulation on the near boiler piping and perimeter mains is 90%-95% intact. Thanks.