Steam radiators

Residential steam radiators incorporate an old heating technology, rather inefficient and largely outdated.

If you have a steam heating system, replacing it is often the best option. If you can’t replace it, and since most systems are oversized, downsizing is also advisable.

Though it’s impossible to overcome the intrinsic inefficiency of steam heating, there are some points you may check and fix in it in order to get some energy savings.

Replacing a steam radiator system

If at all possible, replace your steam system with other system: radiant heating, hot water baseboards… are examples of other water-based heating options, with a much higher efficiency. Besides radiant heating and can be connected with solar solutions (or, more commonly, with high efficient boilers), which will have a friendly impact in the environment.

Reducing and downsizing your steam system

If you intend to maintain your steam radiators, try to reduce their capacity by installing radiator plugs or thermostatic valves. The downsizing of a steam heating system involves replacing some radiators, shifting them, etc.

Downsizing the steam radiators is common in new home conditions, adapting buildings to new conditions: some decades ago, building were much less insulated than today, and steam radiators were often oversized by installers to avoid heating insufficiencies during the cold months, and because energy was cheap.

Reasons for the inefficiency of steam radiators

It’s difficult or impossible to improve significantly the efficiency of a steam system. The boiling and condensing water process is intrinsically non-efficient, and involves significant lag times between the switching of the system and the arriving of steam and heat in the radiators – which also invalidates the use of programmable thermostats.

But... in spite of that limited improving efficiency margin of steam heating, you still may get some energy savings acting on some sources of that inefficiency: bad pipe insulation, clogged air vents, etc.

Below, we list some typical points of improvement.

Pipes insulation
Reflectors
Air Vents
Steam Traps
Pitching problems

Steam radiators & Pipe insulation

Poorly on non-insulated steam pipes will deliver unwanted heat in unwanted areas. If that is the case of your system, pipe insulation is an effective way of getting some energy savings. Just pay attention to the type of insulation: materials (fiberglass…) should withstand the very high temperatures to which the pipes are subject.

Heat Reflectors

Steam radiators connected or communicating with exterior walls are subject to heat losses. To prevent them and get energy savings, homeowners can install heat reflectors behind the steam radiators. The reflectors can be made from insulating materials you might easily buy in building supply stores (foil-covered cardboard, foil and foam board, etc.) and should have at least the same size of the radiators. Face the foil away from the wall. That's a DIY job.

Air Vents

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

Replacing the steam Traps

In two-pipe steam systems (those where a separate pipe returns the water) balancing problems are common: some radiators heat too much, while others provide too little heat. If you have this unbalance, the best way to fix the problem is usually replacing all the steam traps of the steam system.

Steam radiators & Pitching problems

If your steam radiators are causing banging noises and are tilted due to a warping floor (typically due to the radiators heat...), 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).