Kweller, E.
and Palla, R.
(1982),
A test method and calculation procedure for determining annual efficiency for vented household heaters and furnace equipped with modulating-type controls:, , National Institute of Standards and Technology, Gaithersburg, MD, [online], https://doi.org/10.6028/NBS.IR.82-2497
(Accessed October 11, 2024)