I belong to a small condo association (two brick buildings with six total condo units) which currently uses a boiler to heat all units. Three of us have decided to get individual heating for our condos and the others are going to stick with the boiler. The ones who are keeping the boiler have said that an HVAC expert told them that 20% of the energy used by the boiler is dissipated into the walls of the buildings without ever reaching the radiatiors. Therefore, even though we won't be getting any direct heat from the boiler, our walls will be warmed by these pipes and we should contribute to 20% of the gas bill. Our current boiler service company says that this is nonsense and we don't owe any part of the gas bill. Who is correct? Thanks!