It’s a silly thing, but if it glows orange, and if any of that orange light escapes or is visible from the window, it is not 100% efficient. But this is just pedantic in reality, even cheap heaters will do a good job of converting electricity into heat.
It’s a silly thing, but if it glows orange, and if any of that orange light escapes or is visible from the window, it is not 100% efficient. But this is just pedantic in reality, even cheap heaters will do a good job of converting electricity into heat.