The Lost Art of Steam Heat: It’s Not Dead Yet

This week we are featuring a blog from our guest blogger Dan Holohan.  As many of you may know, Dan is a recognized authority on heating systems, which began in 1970 at the urging of his father who counseled, “It’s a good business, kid. You’ll never be out of work because people are always going to need heat. Especially in the winter!”  Dan has written hundreds of columns for PHC News, The Wholesaler, Plumbing & Mechanical, PMEngineer, Supply House Times, OilHeating, Fuel Oil News, Old-House Journal, Contractor, and Canada’s HPAC. You can read more of Dan’s thoughts at

Lots of talk about low-hanging fruit lately – those things we could do to improve the efficiency of America’s older heating system, without having to knock the place down and start anew. As a New Yorker, I’m forever looking at old steam-heated buildings and thinking about how much better they get when a pro who knows the lost art of steam heating does a bit of tweaking. It’s pretty easy to size and position air vents when you’ve learned the secrets, and the results are often dramatic. A buddy of mine recently worked in a 100-year-old apartment building, which had been having heating problems for about that long. He managed to lop 32% off a $35,000 annual fuel bill, and he did this with a couple dozen main air vents. The system found a balance point and, the tenants stopped opening their windows. Simple. We’ve known how to do this since coal gave way to oil and gas in the ‘30s, but few take the time the old ways these days and that’s a shame because when you’re able to do things that others say can’t be done, clients will find you. You know that’s true.

The Empire State Building runs on 1-1/2-psi steam pressure, except for when it gets brutally cold outside, and then they bump the pressure up to 3-psi. They’re able to do this because, just before Christmas in 1899, members of The Carbon Club met in the Murray Hill Hotel in Manhattan and agreed that no steam-heating system installed beyond that date should need more than 2-psi pressure to work well (with the noted exception of a building the size of the Empire State, which needs 3-psi, but only when it’s really cold).

The Carbon Club set the “Two-psi Standard” by creating pipe-sizing charts that pegged the pressure drop of steam in heating pipes to a mere one ounce of loss per 100 feet of travel. This, combined with the definition of “Equivalent Direct Radiation,” which states that a space-heating radiator needs about 1-psi pressure inside it on the coldest day, made everything in the world of steam heating work on low pressure. Neither the physics nor those old systems have changed much since 1899, which means that if you can’t heat the building on low-pressure, it’s probably because you’re not balancing the release of air.

Learn the lost art and go pluck some low-hanging fruit.

We would enjoy hearing from you about your steam heat thoughts.

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