An unexpectedly high electricity bill can make homeowners question whether their heating or cooling equipment is operating efficiently. The first response may be to consider replacing the air conditioner, heat pump, or another major appliance, but high energy consumption can have several causes. Before comparing home energy improvement loans, a household should investigate usage patterns and determine whether professional assessment could identify a less expensive solution. Spending money on the correct improvement is more valuable than financing a new system without understanding the problem.…