I don't think this is true. There are efficiencies involved. Here are space heaters with measured wattage:
(h,m,l=hi,med,low os=oscillating f=fan i=idle)
Lasko Ceramic (upright): (hi/os)1311/1312, (lo/os)930/934, (i)1.2w
Pelonis (walmart $10): (h)1175 (m)772 (l)528 (f)14
Presto Heat...