In a perfect world you could choose the prettiest radiator of them all and install anywhere you want in your home. Unfortunately, there is a remarkable difference in the usability of each radiator, as they were designed with different purposes in mind. You don’t want to overheat your home, as that could generate health issues, that is money down the drain and it’s terrible for the environment. But you also don’t want to be freezing in your own house.

So looking at a radiator’s heat output is essential in getting it right. We have gathered the most important questions you need to answer in order to find the radiator with the right output for your home. So read along and learn more about your heating needs.


Question 1: What type of heating system do you use?

First, you need to know what kind of heating source you are using. Do you have district heating? Oil? Gas? Pellets? Ground or Biomass? The kind of system you use is important in deciding the temperature set you need to be looking at, which will eventually tell you the radiator’s output and whether or not it’s right for you.

A temperature set is comprised of three numbers: The temperature of the water flowing into the radiator, the temperature of the water returning from the radiator, and the room temperature. For example, a temperature set could look like this: 75/65-20 meaning 75˚C flow, 65˚C return, 20˚C room.

This is the regular temperature for Denmark where district heating supplies 64 % of all homes. Your temperature set will depend on your country and heating system.


Question 2: What type of house do you have? 

In order to figure out how much heat you need, we need to figure out how much heat your house is letting out against your will, so to speak. This depends on the year you house was built, the level and quality of insulation, and the type of building it is. Calculating this is called “dimensioning heat loss”. Take a look at this table and find the values that best fit your house. You then get a value determining your approximate heat loss in w/m2. You need to keep that number in mind when calculating the w/m2 needed to heat a specific room in order to get a more realistic view of what kind of heat output you actually need.

Dimensioning heat loss


Question 3: What size of radiator are you looking for?

Now we’re getting into style a little bit, and really – that’s the exciting part. If you already have a radiator you are trying to replace, it’s quite simple: you just need to find a radiator in the same size OR at least one that fits the tappings (piping).

If you don’t already have a radiator, you have a little more creative freedom. What style are you looking for? Do you want a large statement radiator, maybe as a colour block on your wall? Do you fancy a vertical radiator to save wall space? Or maybe you would like a small, ornate cast iron radiator? In any case you need to decide on dimensions of the radiator because as logic will have it: a small radiator generates less heat than a large radiator of the same kind.


Question 4: What size is the room you are trying to equip with a radiator? AND How many radiators do you need in the room?

You already decided the size of the radiators in the previous question, so now we need to figure out how many of those you need to heat the room of your particular size. If you are trying to equip several rooms with radiators you will need to repeat this step for each room.

This question is going to limit your choice of radiators, but it is essential in getting the right temperature. Finding out the size of the room and dividing it with the number of radiators you want will tell us exactly how much w/m2 each radiator needs to have to heat up that specific room.

Under each of our products you’ll find a tab called “Downloads” where you will find Conversion Tables and Output Tables and that will give you the output of each radiator.


Alright, now you know how to choose a radiator with the heat output you need. No more worrying about wasting energy and money on your heating bill, because you’ll be getting exactly what you need. Then it’s just smooth sailing and happy radiator-hunting from here on out.