ACCA members ended 2013 feeling upbeat about their business prospects.

Those are the findings from the latest Air Conditioning Contractors of America’s Contractor Comfort Index, which was released Monday.

For December, the index was at 67 on a 100-point scale. The number is markedly higher than a year earlier, when it was 52. The ACCA index has reflected positive feelings among members for most of the year.

The index is created by surveying ACCA members on how they feel about new business prospects, existing business activity, and expected staffing levels in the short term. A number of 50 or above says most members are feeling optimistic about their businesses.

The next index will be released at the end of January.