Bryan asks:

I need help specifying a high SEER roof mounted commercial HVAC system of 25 tons cap. Dual stage compressor, make up air, and energy management systems should be built in. Do you have any suggestions?

James Elledge replies ...

I have located some information that should assist in your quest to find the best system for your location and application. The first resource I recommend is from Pacific Gas & Electric (PG&E). The publication, “Efficient Packaged HVAC Systems for Commercial Facilities,” is a great resource for recommendations, manufacturers, and other related information. This document is available as a .PDF file at www.pge.com/003_save_energy/003c_edu_train/pec/info_resource/online_rc.shtml.

The next highly regarded resource is the ARI Directory of Certified Product Performance from the Air-Conditioning & Refrigeration Institute. This online database is available at www.aridirectory.org/index.html.

Also for download is “Operations and Maintenance Best Practices...A Guide to Achieving Operational Efficiency Release 2.0.” This is available from www.eere.energy.gov/femp/pdfs/omguide_complete.pdf.

Thanks for your question.

Jim Elledge