Effecient steam gas boiler installation

jamesfiro

I currently have a steam gas 2 pipe boiler installation. The boiler and seperate water heater are in an unheated basement and feed 3 heated levels above. I have 2 questions. When shopping around for a new boiler I get different opinions on how the job shoudl be done. One installer said I need release valves added to the oversized lines to displace the cold air as the hot steam builds to increase effeciency. The other installer said the anti knock valve in place is suffecient and no valves or vents are needed or reccomended. Are release valves needed to be added to my system? My second question is do I need to insulate the lines in the basement. One said that it is best to leave them uninsulated because the basement heats the floor above. Another said to insulate. Thank you for any tips or advice.