Maintaining
A Healthy Pulse
by William A. Lotz, P.E.
The pulse furnace was developed by
the Institute of Gas Technology in
Chicago back in the 70s. It has been
the greatest advance for residential gas
furnaces since the invention of the
return fan.
Lennox was the first to market the
product for warm-air furnaces and
Hydrotherm sells a pulse hot-water
boiler. Several companies have
jumped on the bandwagon with
condensing furnaces. Unfortunately
some of these companies have had
terrible corrosion problems with their
product.
The pulse furnace is only made by
Lennox. It is a condensing furnace,
meaning that water condenses in the
process of extracting Btus from the
exhaust gas. This results in a thermal
efficiency of over 90 percent. Many
other companies