Infrared heaters are personalized heating devices, or more clearly, it warms only the surface they remain focused on instead of the entire space.
So, I can’t conclude by saying, “Go for X BTU for Y Square Feet Rooms or Patio!”
Instead, we need to consider where you want to place it. Is that an open patio or enclosed room, or Garage? If enclosed, then how good is the insulation?
Most importantly, how many people do you want to cover between that infrared heat at a time? Which I call the infrared warmth radius.
Let’s dive in…
1. What size infrared heater do I need for indoors?
Infrared heaters contain reflector mirrors to focus the heat forward, but few household models have fans inside. So I will discuss both scenarios.
Sizing Fan-forced infrared heaters for bedroom
These models come with a power of 1500W and work almost similar to a fan-forced ceramic heater.
If the room remains insulated, a 1500 Watt infrared heater is sufficient for a 150 sqft room, but old homes and lower insulation might cause a lack of warmth.
Here’s a test result of the 1500W infrared heater’s performance inside my 150 square feet well-insulated room.
| Infrared Heater Settings | 0 Min | 15 Min | 30 Min | 45 Min | 1 Hour |
| MAX 1500 Watt | 55.2°F | 60.9°F | 62.4°F | 65.6°F | 66.2°F |
| MIN 750 Watt | 55.2°F | 65.8°F | 67.35°F | 70.20°F | 73.5°F |
Sizing Reflector Infrared Heater for Living Room
Reflector models don’t heat the whole room. Instead, they only spread warmth towards its front focal points. For 110V household power sockets, you won’t find more than 1500W (MAX) models, which is sufficient to warm objects of 10-13 feet away with around 60° radius like the Image.
This Image shows my test result on how much warmth the infrared heater has reflected in my 11 feet lengthy room.
As you’ve noticed, if you sit just in front of the infrared heater, you will feel warmer (73.4°F~65°F) than sitting in a corner. Again, increasing length or moving towards the corner will decrease the warmth gradually up to (65°F~60°F).
Another fact I’ve noticed while testing the temperature, you will feel sufficient hot towards the heater. But your back will remain chilled.
For example! It’s like facing toward the sun in space! Your front side will feel burning hot, and the back portion will get frozen! (I’m Kidding. But it’s the scenario.)
So, I would always suggest you pick a fan-forced infrared model for the bedroom or living room, which will raise your entire room temperature. So you will be able to sleep comfortably.
But, in case you want to install an infrared heater for super large indoor spaces like a hall room, you need to pick one among some 240V models.
Those are available in 2KW, 3KW, 4KW and 6KW variants.
I’ve described them briefly in the garage and patio section.
Bellow a video on how the temperature drops with distance while using the Infrared Heater.
Now, Infrared heaters are also available in natural gas/propane variants which could be used in large living rooms. Also, those require the lowest hourly cost among all other types. You may go through my article to learn more about natural gas space heaters where I’ve described more briefly!
2. What size infrared heater do I need for the Garage?
Generally, 2KW infrared heaters are perfect for one car garage. However, 3KW infrared is sufficient to handle a two-car garage.
As you know, the average dimension of a one-car garage is (12 X 16) square feet, and a two-car garage remains around (24 X 24) to (24 X 30) square feet.
As I’ve previously mentioned, these high wattage infrared heaters (above 2KW) require 240V to run, and your Garage must need to have that compactable power outlet with an adjacent breaker.
I’ve tried the 2KW infrared heater inside my one-car Garage, which is around (12 X 13) square feet, and there I’ve few open spaces to store my garage components.
When I kept my garage door enclosed, the infrared heater was throwing warmth almost 12 feet away, and I felt practically 75°F temperature standing directly in front of it. While I was moving sidewise, the temperature dropped to 67°F, which is natural.
Here’s an image describing how much warmth I’ve felt with the infrared heater inside my Garage.
If you have an oversized garage and need a more powerful infrared heater then I have a ninja hack. Before sharing that, below is a price chart of various wattage infrared heaters.
Now, installing a high wattage infrared heater will undoubtedly produce much heat, but that won’t increase its working radius. However, you won’t work or use an exact point/space of your Garage.
So, instead of installing a high wattage infrared heater like 4KW to 6KW, installing multiple 2KW devices in several places is a better decision. Cause you can only heat the portion, you want to use at a particular session.
Note: High wattage infrared heaters are ceiling mount and require 12-inch clearance at its top and 18-inch clearance at its side. So, before you size an infrared heater for the Garage, ensure your garage ceiling has enough clearance.
As I’ve said, infrared garage heaters only transmit heat towards its front direction, so you mightn’t find your entire garage space equally hot. To avoid this issue, you may read my article where I’ve described on 240V fan-forced garage heater.
3. What size infrared heater is required for an uninsulated patio or outdoors?
While the environment temperature remains around 50°F to 60°F a 4000 Watt infrared patio heater will cover about 100-110 square feet areas and be able to raise the temperature to 73°F to 75°F depending on airflow and your surrounding walls and ceiling height.
Note: I know brands claim those 4KW patio heaters can handle up to 250 square feet’s patio spaces, but that’s not true. I’m writing based on my personal experience!
My patio space is 11 feet long and around 10 feet wide with an 8.5 feet ceiling height. There I’ve three two-seater recliners.
So, I’ve installed a 4KW infrared heater at the ceiling, just in the middle of my patio. The top clearance of that device was around 8-inch. Also, the 4KW infrared heater is about 5 feet in length.
Here’s how I’ve organized my patio with the 4KW infrared panel.
While I’ve tested, the outside temperature was 55°F. At the top of my recliners, my thermometer gave a reading around 73°F~75°F.
Sitting under the infrared patio heater was comfortable, but guess what! The space under the tea table remains cold, and none have anything to do with it. Sadly.
So, if your patio is more extensive than mine, like 16 X 16 square feet or more, you will require a 6KW infrared unit.
But again, I would suggest you install multiple 4KW models instead of the largest one. Cause the higher wattage unit produces much heat, but the warmth radius doesn’t get increased that much.
However, you may consider choosing a propane cabinet heater to enjoy a backyard BBQ party instead of an electric one. Cause those are 100% portable and extremely powerful. To learn more, please check my propane cabinet heater review here.
You may read the article titled Infrared Heater on Wikipedia to learn all theoretical facts and mechanisms of infrared heating technology.