A consumer buying cooperative tested the effective heating area of 20 different electric space heaters with different wattages. Here are the results

Heater Wattage Area 2,900 112 1, 250 71 1, 500 187 1, 500 236 10 0 J G U P W N P 2,900 265 1, 900 127 1, 500 194 2,000 186 1, 900 93 10 2,000 236 11 1, 500 85 12 1, 900 100 13 1, 250 208 14 1, 250 176 15 750 58 16 750 151 17 750 70 18 2,000 187 19 750 142 20 1, 500 163