If you are replacing an existing heating appliance with a new one of the same type, it’s smart to invest in the most efficient model available, to minimize energy use and operating cost. If you’re considering a new type of heating system, compare different systems for up-front cost, energy efficiency, noise, space requirements, and other important features.
The cost of a heating system includes the cost of the unit, installation, and upgrading or repairing the distribution and ventilation systems, as well as the operating cost. Over the life of the equipment, the highest of these is usually the operating—or energy—cost. Long after you’ve made the last payment on the system, energy bills keep coming in. So keep energy efficiency in mind as you weigh your choices, and ask yourself if energy prices are likely to go up during the life of your new equipment.
Consider how much heating capacity you really need. If you’re adding on to your house, don’t assume you’ll need a larger system. If you’re not adding on, don’t just get the same-size equipment you now have. Many contractors put in oversized equipment to compensate for leaky houses, poor insulation, and badly installed ducts. Insulate and air seal before you have your heating system sized, or you’ll pay more than necessary up front, and more every month.
To avoid buying a bigger system than you need, start by getting a home performance assessment. Use this information to decide which improvements are worth making before you choose a new heating system. Then have an HVAC professional calculate how much heat your house needs. Ask to see the load calculations, and look for Manual J and Manual D on these sheets—the industry standards for calculating heating and cooling loads and designing duct systems.