Steam radiators

Residential steam radiators are an old and rather inefficient and outdated technology. If you have a steam heating radiator system, consider fixing some of its flaws (or replacing the system...).

Since steam radiator systems are often oversized, reducing their size is a way of improving their efficiency. But you may also try to fix some weaker points...

Though intrinsically inefficiency, there are some points that you may check and fix in order to get some energy savings.

Replacing a steam radiator system

If you are considering to replace your old steam radiator system with a new hydronic (hot water) system, you have two main options: hot water baseboard heating and radiant floor heating. These systems demand an high initial investment, but are both highly prized for their high-quality heating.

Reducing and downsizing your steam system

Many old buildings with steam radiator systems have benefited from new and more efficient windows and doors, or from attic and other types of insulation and air sealing... That makes them more energy-efficient, and with smaller heating needs, but can also make their steam radiator systems rather oversized...

If that is your case, you should try to reduce the capacity of your steam system by installing radiator plugs or thermostatic valves, or by replacing some radiators, shifting them, etc.

Inefficiency

It’s difficult or impossible to improve significantly the efficiency of a steam system. Their process of boiling and condensing water is intrinsically non-efficient, implies significant lag times (between the switching of the system and the arriving of the steam and heat to the radiators) and prevents the use of programmable thermostats.

But... notwithstanding that limited improving margin you still may get some energy savings acting on some sources of inefficiency: bad pipe insulation, clogged air vents, etc. Below, we list some typical points of improvement.

Steam radiators & insulation

Poorly on non-insulated steam pipes will deliver and loose heat in unwanted areas. To fix it, consider pipe insulation. Just pay attention to the type of insulation material, which should withstand very high temperatures.

Heat Reflectors

Steam radiators connected or communicating with exterior walls are prone to heat loss. To prevent it and to get energy savings, homeowners can install heat reflectors at the back of the steam radiators. The reflectors are typically made from insulating materials that you can purchase in home improvement stores (foil-covered cardboard, foil and foam board, etc.) and should at least match the size of the radiators. That's a DIY job.

Air Vents

One-pipe steam systems (those where the pipe delivering the steam and the water is the same) use air vents on each radiator. These air vents bleed air as steam fills the system, and should be cleaned regularly or even replaced. Clogged air vents are a common cause of the very low-efficiency of steam heating.

Replacing the steam Traps

In two-pipe steam systems (those where there is a separate pipe for the water) pay attention to balancing problems: some radiators heat too much, while others heat to little. If you have this problem, the best way to fix it is usually by replacing the steam traps.

Steam radiator Pitching problems

If your steam radiators are making banging sounds or are tilted due to a warping floor, shims should be inserted under radiators to pitch them correctly: slightly toward the pipe (in the one-pipe steam systems) or slightly toward the steam traps (in the two-pipe steam systems).