The Air Conditioning Contractors of America said the third edition of its Manual S has been sent out by ANSI for public review.

The revised standard covers selecting and sizing residential HVAC equipment. It comes in two parts: one details the selection/sizing criteria and the other covers discussion, guidance and example problems.

The American National Standards Institute’s 45-day public review period concludes April 7. Copies of the changes and the comment form can be downloaded at