Making smart decisions about your property’s equipment can have a big impact on your monthly gas bills! How much of your hard-earned money are you throwing away on your gas bill? If you have a 70% efficient furnace, $0.70 of every dollar spent on your gas bill is used to heat your home or office. The other $0.30 goes out your chimney. If you have a 95% efficient furnace, $0.95 of every dollar is used to heat your property and only $0.05 is wasted.