How Does Steam Heating Work?

Woman warmed by radiator

What is the History of Steam Heating?

In the early part of the 20th century, steam heating was the popular form to heat homes. It was efficient, and reliable, and let’s face it, technology was not as advanced as it is today. Many of us that were in elementary school up through the 60s and 70s would recognize steam heating as what we called radiators.

How does heating by steam work?

Steam heating is an original form of forced-air heating system that heats by converting water to steam using a boiler. The steam is moved through pipes using a pump and the pipes send the heat throughout the home with blowers and registers circulating the steam. 

Is steam heating available today? 

Any of us that grew up with steam heating, aka radiators, miss the amounts of heat they put into a room. We don’t miss the smell of crayons melting on them though! While there may be steam heating systems available with some extensive search, it would be challenging to find a plumber to install the system. There are still some plumbers around to do repairs though, but again, challenging in finding them. 

But why isn’t steam heating still used today? Because it is not efficient in heating in relevance for the money it costs. The pipes get cold, and that depletes the heated steam going through the pipes. That in turn requires more steam to be produced. A vicious cycle that modern technology found not worthwhile. So, this brought about the creation of the HVAC system way of heating a home. 

What are the different types of steam heating systems? 

There are four key types of home heating systems:

  • Furnaces
  • Boilers
  • Radiant heating systems
  • Space heaters

Where steam heating broilers are still in existent, there are two key types: 

Fire tube

The fire tube boiler type has a water vessel with banks of metal rods running through the center. Heat is applied precisely to the water through those rods. The metal rod banks ensure that the heat circulates through the vessel several times before the heat escapes through the chimney. This type of steam heating has the most water storage space available and provides maximum exposure for the maximum amount of heated surface possible.

Water tube

Water tube boilers are almost the complete opposite with the water being contained inside vertical tubes. The heat is applied to the tubes instead of the water which enables it to generate more steam per hour than what the fire tube steaming heat method does. The downside to this type of steam heating is that less water storage is available. 

What are the differences between steam heating and other forms of heating? 

Steam heating systems, as we just reviewed, heat water to a boiling point. This creates steam that is then distributed to radiators that are installed in each room of the house. The steam turns back into the water after it has cooled and the process repeats. While it was determined steam heating wasn’t an efficient way of heating, the air was cleaner, and the heat lasted longer than today’s HVAC systems. 

An HVAC heating system is a forced air system that heats up faster, and with each room having air vents, the amount of heated air can be adjusted. HVAC systems can be combined with air conditioning is another plus over steam heating systems. 

What are the benefits of steam heating? 

Today, with many homeowners wanting that nostalgia of yesteryear, steam heating radiators are a desired look, even if not connected and used. The benefits of steam heating include: 

  • Steam heating is humid, making the home more comfortable on cold winter days and nights because the moisture isn’t removed from the air. 
  • Steam heating radiators can be turned off or on in each room as needed. 
  • Steam heating repairs can be done per room instead of the entire system being repaired in most cases. PRO: In some cases, individual pieces may be easier to replace if facing defects/issues
  • Steam heating systems are typically quieter than HVAC-forced air systems.

What are the common issues associated with steam heating systems? 

Steam heating is a thing of the past in popularity, but if you’re fortunate enough to purchase a home that has existing steam heating in place, there are some problems that you may encounter: 

  • Water hammering

Steam condensation collects in the lowest points of the pipelines. If that isn’t drained, it is picked up and begins a hammering sound as it slams against the pipe walls.

  • Freezing up

When the steam heating system isn’t insulated, the water can freeze up, resulting in no steam being created and no heating for the house. 

  • Air binding

The air mixes with the steam and since air is non-condensable, it doesn’t return to the boiler, and this creates air pockets. This traps the steam and prevents circulation. 

  • Steam binding or locking

Like the air binding, the steam gets trapped in the horizontal pipes, restricting circulation. 

  • Dirt and scaling build-up

If the area where you live has poor water quality, it can damage the steam heating system. You will need to install a water quality device that collects excessive calcium and minerals to minimize the build-up. 

  • Corrosion 

Corrosion can form anywhere within the boiler, and in fact, it is a common problem if the pipes are not drained from time to time. 

What kind of maintenance does a steam heating system require?

Caring properly for your steam heating system will you save money and provide greater efficiency. On a regular basis, perform the following three things every month: 

  • Check the steam gauge 
  • Check the safety valve 
  • Check the water level 

What safety measures should be taken when using steam heating?

If you’ve ever held a hand over a pot of boiling water for too long, you know it isn’t something you’d want to experience in a greater capacity. Some safety things you want to make sure you do to keep your steam heating safe: 

  • Low-water cutoff flushing: If your steam heating system has a low-water cutoff with a float, it should be flushed every week during the winter.  
  • Steam pressure lowering: You don’t want the pressure too high because it wastes fuel. 
  • Pipe insulating: With the pipes insulated, the steam will last longer. 
  • Supply valves repacked: If the stem around the radiator supply valve is leaking, it can be repacked. 

 Steaming It Up – The Energy Cost

Energy efficiency was the biggest reason that the HVAC system came along. So, just how much energy does a steam heating system use?  The average steam heating system thermal cycle efficiency is just over 56%. This means that almost 44% of the energy consumed by boilers is lost. For steam heating in Somerset, MA or to receive a consultation, please reach out to our plumbing company at (508) 272-1196 now.