Radiator Heaters 101: Your Guide to Old-Fashioned Heat

Invented in the mid-1800s, the concept of radiator heaters has a long history of keeping people warm. Over the years, this type of heater has slowly evolved into the low-maintenance, energy-efficient heaters that we know today.

While it’s no longer the leading type of heater nowadays, it still works great at keeping you and your family warm. Take a look at how a radiator heater works, the pros and cons of owning one, and whether it’s the right fit for your home.

How Radiator Heaters Work

There are two main types of radiator heaters to know about: electric and steam.

Steam Radiators

Steam radiators work by boiling water to create steam. That steam then travels up a set of pipes into the radiator, which then heats up the room via radiation and convection. As the steam travels through the unit, it slowly cools down and turns into condensation. This condensation then goes through the unit, ending its travels back in the boiler, where it is ultimately turned back into steam.

This is the old-fashioned radiator heating method. It would be unlikely for you to find this type of system in newly built homes. While it’s no longer the preferred method of warming up homes in the U.S., this type of radiator heater is still in use around the world today.

There are a few versions of steam radiators you can choose from, if you’ve decided that this is your preferred heating method. These options include:

Cast-Iron Freestanding Systems

The oldest version of a radiator heater, the cast-iron system is very efficient at heating up the room. It also takes up the most amount of room and takes the longest to heat up. Despite these two downsides, its design allows the cast-iron system to hold that heat for the longest period of time.

Baseboard Steam Systems

Not to be confused with typical electric baseboard heaters, this type of steam radiator works on the same premise of steam rising and condensation falling; however, they take up very little room in your home. You can run them along the baseboards of your home in a very discreet manner.

Ceramic Systems

This is the newest version of a steam radiator. Unlike its predecessors, it’s not hot when you touch it and it’s more efficient at supplying sustainable heat. If you were going to choose a steam radiator to heat your home, this is the one to look for.

Electric Radiators

This type of radiator is typically built in similar fashion as a steam radiator; however they utilize a different method of creating heat. At a radiator heater’s core is a metal reservoir filled with a special mineral oil.

This mineral oil, more aptly referred to as “thermal oil” or “heat transfer oil,” is not burned in the process of heating, so it does not need refilling or replacement. It has an uncannily high boiling point and specific heat capacity, which allows small volumes of the oil to emit remarkably high quantities of thermal energy without evaporating. Evaporation causes unsafe levels of pressure to build up in enclosed spaces, so its absence from this process makes radiator heaters much safer.

At the bottom of the heater is a heating element similar to what is found within an electric stove. It is electrically powered and is used to heat up the oil. Once the oil is heated, the warmth is convected throughout the body of the heater, warming its walls. The heat is then conducted through the metal walls and radiated into the surrounding space, filling the room with wonderfully cozy warmth.

3 Benefits of Radiator Heaters

There are many benefits to having a radiator heater. It must be noted, however, that you can also find many of these same benefits in other types of heaters.

1. Safe

First and foremost, the main benefit is the level of safety offered to the end user. Many portable radiator heaters come equipped with a tilt sensor, which cuts the power if a radiator heater is unbalanced or knocked on its side. The heaters also retain heat well, which makes them ideal for extended use.

While it’s still not advisable to leave flammable materials draped over their surfaces to dry, they are much less of a fire hazard than other forms of heaters, such as space heaters that require more safety considerations. Lastly, they do not emit any harmful odors, gases, or chemicals when used, unlike many gas heaters that require ventilation to be installed.

Note that some radiators will become hot when they start to produce heat. Learn more about this below.

2. Less Maintenance

Radiator heaters require much less maintenance than many of their counterparts do. They do not contain any fuels that need replacing, and ventilation (or lack thereof) does not compromise warmth. Make sure you buy one that has a built-in adjustable thermostat, as this will help prevent wasted heat and lower your overall energy usage.

3. Reliable

For the most part, radiator heaters are extremely reliable. If you installed a cast-iron radiator in your home today, it’s likely that it will last for years—and maybe even decades. This isn’t always the case, which is why it’s important to thoroughly research every product and brand before you purchase one.

3 Downsides of Radiator Heaters

Just like everything in life, the benefits of radiator heaters also come with their own set of downsides. To some, these may not be a big deal, but they’re worth noting so that you can avoid a surprise down the road.

1. May Become Loud and Noisy

Some radiator heaters, especially steam radiators, can become noisy over the course of time. If you live in an older home with an old radiator heater in the corner, then you’ve probably heard random noises coming from your unit. These may include squeaking, banging, and whistling. These unwelcome noises become very annoying for many homeowners. If you’re experiencing this, it would be wise to call a plumber to come check it out.

2. Airflow

Another downside of a radiator heater is that it must have proper airflow around the unit to effectively disperse heat around the home. Without this airflow, it’s impossible to thoroughly heat your home. Of course, different size radiators will create different amounts of heat. But creating the heat isn’t the problem here. It’s getting that heat across the room that can be somewhat challenging, especially if you have limited space and there are items crowding around the unit. This isn’t a problem with other types of heaters available.

3. Hot to the Touch

The biggest downside is that some radiators will become very hot as they start to produce heat. If something is touching the unit, such as drapes or a couch, then it may get damaged or catch fire. If your children or pets touch the unit, they might get burned. While this isn’t the case with all radiator heaters, it is definitely something to consider when researching which heater is best for you.

Tips for Using Your Radiator

If you have a radiator heater mounted on an exterior wall of your home, then it’s possible that you may be losing some of the heat produced to the outside elements. This is particularly true if that exterior wall has poor insulation or drafty windows/doors nearby or the radiator is recessed within the wall.

One trick to prevent this heat loss is to add your own heat-resistant insulation directly behind the radiator. A sheet of foam insulation with aluminum on one side will work great at accomplishing this. You can make your own with tin foil and insulation or buy a pre-made sheet at your local hardware store.

Simply slide this sheet of insulation between the wall and the heating unit, with the aluminum side facing the heater. This will help prevent the heat from slowly seeping out of your home and redirects it back to your living area. While it may not complement the rest of your décor, this small addition will cost less than $20 but instantly starts saving you money on your energy bills.

Are Radiators Better Than Other Heaters?

The answer to this question all depends on your situation. For some people, a different type of heater—one that helps heat travel further—could probably suit them better.

Heating methods have become more efficient over time as the technology inside them evolves. A hundred years ago, nothing could beat a radiator heater. Nowadays, however, you may be better off with a different kind of heater that produces similar amount of heat and disperses it around the room more efficiently.

But take a look at your living situation. If you live in the Northeast where it snows most of the year, a permanently installed radiator heater or wall-mounted heater may be the best fit for you. If you live in the South where it’s only cold for a few days out of the year, a portable space heater could provide the right amount of heat and is easy to store when you don’t need it.

Is It the Best Heater for You?

All in all, radiator heaters are an incredibly versatile and affordable source of supplemental heat. They are reliable, durable, low-maintenance, and energy-efficient. It’s a great unit to help you follow a supplemental heating strategy.

Whether you use a radiator, wall heater, or baseboard heater, having a smaller source of heat that doesn’t require you to warm up the entire home will save you money in the long run.