When selecting a heating system, consider the following three characteristics carefully: the energy efficiency rating, sizing, and the system’s components.
Energy Efficiency Rating
The U.S. Federal Trade Commission requires manufacturers to provide an annual fuel utilization efficiency (AFUE) rating on all heating equipment. This rating provides consumers with information about the operating costs of a particular model that is being considered.
Boilers and warm air furnaces available today have an AFUE rating of 78% to 97% compared to heating appliances of the past that had ratings as low as 65%.
An illustration, but not actual data, of how the AFUE ratings compare. A heating appliance that has a 65% AFUE rating will utilize sixty five cents of every dollar of fuel that you purchase. The remainder of the heat 35% is directed to the outdoors via the chimney. A heating appliance that has a 97% AFUE rating will utilize ninety seven cents of every dollar of fuel that you purchase and only 3% is directed outdoors via a plastic pipe.
The initial purchase cost of a 97% AFUE heating appliance is greater than a lower AFUE rated appliance, but in cold climates, the increased costs can be offset in a few years.
When selecting a new heating system, it’s important that you determine the proper size needed for your home. Bigger is not better. Oversizing causes the heating system to start and stop more frequently, which is less efficient and harder on the components than letting it run for longer cycles. A properly sized heating system will also provide you with better comfort and humidity control than an oversized one.
The capacity of heating systems is measured in Btu (British Thermal Unit) per hour. Correct sizing procedures involve complex calculations, which are best performed by an experienced contractor, who uses sizing methods accepted by the heating industry. Don’t employ a contractor who guesses the size of the heating system needed. Rule-of-thumb sizing techniques are generally inaccurate, often resulting in higher than necessary purchase and annual energy costs.
You and your contractor should discuss options that will help improve your home’s comfort and the economy of your heating system. Regarding ducts, for example, it’s important to carefully consider their design and materials, as well as the proper amount of space they require. Check your home’s blueprints to see if the architect and builder have planned adequate space for ducts and fans. Heating and cooling contractors complain that they often have to squeeze heating and cooling systems into spaces that are too small, resulting in constricted ducts and inadequate airflow.