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Baseboard Heater Size and Watts Guide – How to select the right heater?

How to Select the Right Baseboard Heater for a Room?

Finding the right baseboard heater for a room isn’t something simple as finding the biggest heater with the highest wattage. You have to account for the size of a room in relation to the type of heater you’re buying. 

Let’s go through the steps you should take to find a heater you will be satisfied with for the next 20 years. 

How Much Wattage Do You Need for a Room? 

While you can’t know the exact wattage a room needs to heat up a room or house, you can get close to it by applying some basic math formulas. 

These formulas could have given you the exact wattage you need a baseboard heater to produce if not for how widely homes differ. The number of windows and the pre-existing insulation type inside the walls and roof of a house also play a part in determining the heating required. 

Basic Method

The easiest and the most often used formula involves figuring out the square footage of the area the baseboard heater will be mounted and then multiplying it by 10 watts. 

This is the base wattage a room could need. In reality, depending on how cold the room is naturally or how much it traps heat, the wattage requirement could be more or less. 

Basically, you measure the length and breadth of a room. Suppose you have a 20-foot x 30-foot room. The total would be 600 square feet. Now, multiply 600 sq. ft by 10. 

The total wattage of heat required for the room is 6000 watts. 

Additionally, this method only accounts for a home with standard modern wiring for wall, floor, and ceiling insulation. There is also the presumption that the height of a room is about 8 feet. 

You have to make the following adjustments if the room differs:

  • For an older home, swap 10 watts with 12.5 watts while multiplying the square footage. 
  • If the home is ultra-insulated, reduce the 10 watts to 7.5 watts during the multiplication of the square footage. 
  • Add 25% to the ultimate wattage result if the room is 10 feet high instead of 8 feet. 
  • Add 50% to the wattage result if we are calculating for a room with a 12 feet high ceiling instead of 8 feet. 

Suppose a room is under-insulated but it receives massive sunlight and has windows, you can stick to regular calculations. 

Usually, the highest watt a baseboard heater produces is about 2500 watts. So, to make up for the lack of appropriate heat in a room, you might have to mount the heater on either end of the room, typically underneath the window. 

The most common baseboard heaters have 1500 wattage production. You will have to buy about 4 of them for a 600 sq. ft standard room that needs 6000 watts of heat. 

Figuring Out the Length of the Baseboard Heater

In this method, the primary goal is to calculate what should be the length of your baseboard heater. Generally, the wattage a baseboard heater produces is directly proportional to its length. 

The method also assumes for a baseboard heater with a 240-volt connection requirement will produce 250 watts for every foot. 

As before, measure the width and length of the room and multiply them together to get the square footage of the room. Instead of 10, multiply the square footage by 9. 

So, the result for a 144 sq feet room would be 1296 wattage. 

Now, keeping this as the base wattage number, add another 10 percent for each feature mentioned in the room below:

  • Ceiling surpassing 8 feet in height. 
  • 10% for every window. 
  • 10% for every door that goes outside. 
  • 10 % for walls on the exterior. 
  • 10% if the walls don’t have any insulation. 
  • 10 % if there is no insulation below the flooring. 

The number you will get would be the exact wattage of heat the baseboard heater has to produce to sufficiently warm the room. 

To get the length of the baseboard heater out of this, you have to divide the total wattage number by 250. 

The longest baseboard heater you can typically find is about 8 feet. However, the most common sizes available in the market are 4 feet and 6 feet. 

You have to remember a 240-volt heater produces and uses double the wattage of a 120-volt heater. This is the reason the baseline for calculating the length of a baseboard heater is assumed to be on a 240-volt power for this method. 

Choosing a Type of Baseboard Heater

Once you have figured out the wattage requirement for the room and the length of the baseboard heater, it is time to choose between the two primary types of heaters. 

These are electric baseboard heaters and hydronic baseboard heaters

The electric or convection heater collects the cool air in a room, warms up via the metal fins inside, and releases the hot air back into the room. You can either hardwire the electric heater into the walls or floor of the room or you can find portable models which you can plug into an outlet. 

Electric Baseboard Heater

The hydronic heater either has a water chamber inside the unit or is connected to a central boiling system. As such, it can be portable or a mounted, unmoving unit. It boils water or oil and the warm condensation from it is set free into the room to warm up the air. 

Hydronic Baseboard Heater

Portable heaters are available mostly in the 120-volts version. Permanent ones are available in both 120 and 240-volt options. Permanent ones use energy more conservatively and also produce a high amount of heat. 

Hydronic heaters take some time to heat up the room, however, the heat it produces permeates the room long after overheating shut-off has kicked in. 

Electric heaters reach the promised wattage production quickly. However, the room also cools down too quickly once the heater is turned off. 

Convection heaters have to be on constantly during winter months, for this reason, thus using up more energy and hiking your electricity bills. 

Hydronic heaters don’t need to be used constantly, so you save up on electricity. Yet, hydronic heaters cost four times the amount of electric heaters save for some new models. 

Hydronic heaters also need yearly maintenance so corrosion does not occur on the unit. Electric heaters require dusting at most to keep them in good condition for the next 20 years. 

These types of baseboard heaters are also hot to the touch when it’s on for a long time, which doesn’t happen with hydronic heaters. 

Ultimately, which form of baseboard heater you should buy depends on your convenience and which methods let you save up more. 

Heating Recommendation for a Room

If you look up the official website of baseboard heater manufacturers, you will notice they have a general wattage recommendation ready for a room. 

The general consensus is that a 100 square feet room should at least get a heater that produces 900 watts. 

For 150 square feet, the recommendation is 1350 watts and so on. 

A 400 square feet room needs heaters that will combine to produce 3600 watts. 

If we go by the typical wattage production based on length, a 30-inch heater running on 240-volt produces 500 watts. 

It is 750 watts for 36-inch baseboard heaters. A 72 inches baseboard heater easily produces 1500 watts. 

How Many Watts Should My Baseboard Heater Be? 

Your baseboard heater should be 1500 wattage if the room is 144 square feet watt, requiring 1440 watts. 

If your room is about 100 square feet, you can buy a 750-watt baseboard heater and a 250-watt baseboard heater. 

There are baseboard heaters of all shapes and sizes available in the market though the most common one you can get your hands on typically produces 1500 watts on a 120-volt outlet. 

It is always a good idea to get a baseboard heater that produces more heat required than get one that underheats. You can always turn off the heater if you think the room is turning too hot. 

If the inclination of the room is to remain cold when you have the heater on though, it just means you will have to purchase more heaters. 

3 Best Baseboard Heaters for You

We are listing 3 of the basic styles of electric baseboard heaters you might want to consider. 

1. Fahrenheat FBE15002 Portable Electric Baseboard Heater

This electric baseboard heater from Fahrenheat is a portable model. Despite being 45 inches in length, the heater produces 1500 watts and works on 120-volt circuit boards.

Set-up is particularly easy due to the portability factor. There is overheat protection so in the event the heater gets too hot, it will shut off on its own. 

Customers have applauded how quickly it heats up the room and how much the warmth seems to stay despite being this being an electric unit. 

Best features:

  • More wattage compared to heater length. 
  • High energy production on 120-volts. 
  • Overheat protection. 
  • Plug-in heater. 

2.Cadet F Series 36 in. Electric Baseboard Heater 

From Cadet, this electric baseboard heater is about 36 inches, thus producing an expected 750 watts. However, it works on a 120-volt plug. 

You will also have a buy a thermostat in addition to the heater. The material required for installation comes with the package. Still, you can always employ a professional electrician if you’re wary of doing it yourself. 

 Best features:

  • UL listed. 
  • High-temperature shut-off feature. 
  • Pre-punched for installation.
  • Powder-coated for protection. 

3. Comfort Zone® Low Profile Baseboard Digital Silent

This is one of the most modern units available in the market. 

Barely 10 inches in size and with under 1 pound weight, the baseboard heater can be carried anywhere. Not to mention this is a dual wattage model where you can choose between 750 watts or 1500 watts. 

The LED indicators caution you when the baseboard heater is gets overheated and also shuts off on its own when it goes over the safety limit. 

You can even turn on and off the thermostat. 

Best features:

  • Digital control center. 
  • Overheat shut-off switch. 
  • Timer option. 
  • Dual-wattage. 

Final Words

We hope any queries you had over the right size on the baseboard heater for a room and the watt requirement have been solved. Remember, it is always better to buy a heater that produces more heat than under. Keep this rule in mind while making your purchase!