Natural gas furnace – what exactly is kW?

Question

I have natural gas furnace (which is connected to radiators in rooms), but i keep failing to understand output rating, for example 20kW vs 24kW.

For example, if on both devices output temperature is set 70°C, where does the difference kicks in? Is it only heat exchanger size different, or there is something else i am missing?

In: 0

Answer 1

Electric furnaces are usually rated in kw, gas furnaces are usually rated in BTU. In either case, the rating means the same thing; the total heat output capacity of the furnace. The difference is in a furnace’s ability to heat a larger space, or to heat a smaller space faster. The higher the rating, the larger the space a furnace can heat, or the faster it can heat the same space as a lower rated furnace.