Lower Your Home Energy Costs — 2026 Complete Guide
Part 6 of 24 in Lower Your Home Energy Costs. By Damon Fowler, Trends Kitchen & Bathroom Specialists.
A heating system can produce conditioned air that never reaches the intended room. Leaky connections, damaged ducts, poor insulation, restrictions, and distribution design can all affect comfort and energy use. Replacing the furnace without examining delivery can leave those problems in place.
Location changes the consequence of a leak
A duct leaking into an unconditioned attic or crawl space loses useful delivery outside the living area. Leakage within conditioned space has different effects, though it can still disrupt distribution and pressure. The evaluation should consider both supply and return paths.
ENERGY STAR reports that typical duct systems can lose about 20–30 percent of the air moving through them through leaks and poor connections. That is not a promise that sealing reduces the entire bill by the same percentage. See its duct-sealing guidance.
Situation: the addition is cold but the furnace runs normally
A distant room receives little airflow. The cause could be a disconnected branch, a restrictive route, an inadequately designed addition, or a return-air issue. Installing a larger furnace does not necessarily increase useful delivery to that location.
Ask an HVAC professional to evaluate equipment performance, duct condition, sizing, balancing, and room pressure. Describe how closing doors affects comfort. Avoid randomly closing several other registers in an attempt to force air to the cold room.
Repair with appropriate methods
Duct joints may require suitable mastic, approved tapes, mechanical support, and insulation. Ordinary household tape is not a universal permanent repair. Access, temperature, moisture, and the duct material affect the method.
Do not treat a return cavity or equipment opening as a convenient place to apply foam without understanding its role. Combustion safety and required clearances remain part of the work. Difficult access and mechanical changes belong with qualified people.
Ask how performance will be checked
A proposal should identify the affected routes and explain what repair is intended to accomplish. Testing or measurements appropriate to the system can help verify leakage reduction and delivery. Photographs are useful for hidden connections and insulation.
If new equipment is also needed, coordinate the two scopes. A high-efficiency unit needs a distribution system and controls suited to it. The lowest equipment-only bid may omit work necessary for the system to perform well in the house.
Remember the filter and return path
A blocked grille, unsuitable filter, or restricted return can create symptoms that resemble inadequate equipment. Maintain the correct filter and keep grilles unobstructed. Have recurring airflow problems diagnosed rather than compensating with repeated thermostat changes.
Duct repair earns its value when it corrects a documented delivery problem. It should be part of a system assessment, not an automatic add-on sold with every furnace.