DraftsInefficient single-pane windows, ill-fitting doors and other gaps may account for over 25% of heating Overunity Generator Guide and cooling energy bills in an older home.Keeping windows and doors locked whenever possible will ensure a tighter seal against cold air. Even keeping curtains and drapes drawn can prevent some heat from escaping.However, to effectively improve the energy efficiency caused by drafts, you will first need to identify all the gaps and cracks. Inspect windows and doors to see if they seal tightly, and check to see if latches and locks are still operable. Where gaps are visible on frames, weather-stripping can be applied. Caulking around casings and glass panes may also be replaced.Weather-stripping and caulking can sometimes work as temporary solutions, but they are still just papering over the cracks. In order to achieve substantial savings and long-term solutions, replacements should be considered. Heat loss through inefficient single-pane windows can be reduced by over 25% with storm windows, and there can be even greater reductions with special high-efficiency units.There are several other sources of potential cold infiltration and heat loss in older homes. Gaps surrounding permanently installed air-conditioning and other utility units and vents are all potential energy-loss traps.