How Furnaces Went From Clunky to Cutting-Edge - Sun Heating & Cooling, Inc.

How Furnaces Went From Clunky to Cutting-Edge

furnace history

Furnace technology has come a long way over the years. Let’s go back almost a century in time to the first furnaces, and take a journey through time to see how much they’ve changed.

Remember when furnaces were giant hunks of cast iron that took days to install and gave off more heat than a campfire? Yeah, us either!

The early days

Back in the early 20th century, home heating was all about coal and wood. Massive masonry furnaces with huge fireboxes were common. But they weren’t exactly safe or clean. As natural gas became more available in the 1930s-40s, the industry shifted to modifying existing furnaces to burn gas instead of solid fuels. Early gas furnaces kept the basic firebox design, just with gas jets instead of piles of coal.

While these beasts were pretty good at cranking out heat thanks to beefy steel heat exchangers, they weren’t very efficient. A lot of warm air escaped up the chimney. But in the post-WWII years, technology improved quickly. The industry added things like draft diverters to prevent chimney backdrafting and increase standby efficiency. More complex steel heat exchanger designs improved heat capture. And better controls made these devices a little safer!

Things are getting better

By the 1970s-80s the trend was toward lighter-weight heat exchangers made of aluminized steel rather than heavy cast iron. These high-temp alloys allowed hotter furnace operation and better heat transfer. Next came the addition of electronic ignition systems in the 1980s. No more energy-wasting pilot lights! Around this time we also see the development of condensing furnaces. By extracting moisture from combustion gases, these systems boosted efficiency into the 90% range.

Today’s incredibly efficient furnaces

Modern mid and high-efficiency furnaces continue to push the envelope when it comes to materials, safety controls, decreased electrical consumption, and improved comfort. The latest systems can fine-tune their fan speed based on heating demand, maintaining steady indoor temperatures.

So, we’re no longer hauling coal and firewood down into a basement boiler. Today’s heating systems are safer, cleaner, greener, and light years ahead in efficiency!

Got any questions about upgrading your furnace – or are you worried yours is ancient history? Contact us today or give us a call: (248) 986-1506

Scroll to Top