This fourth of a series of articles on CO2, after a brief review of CO2 characteristics, comparing subcritical and transcritical cycles, presents a functioning transcritical system with a hermetic CO2 compressor and discusses design considerations.

The purpose of this article is to provide a simple explanation of these terms for those who desire a concise understanding as well as a review for those who understand the terms but want to take another look.

For this design/build project, the tribe's architectural firm convinced college officials that a LoadMatch hydronic system would not cost much more than the all-air system they originally called for, and would be more comfortable and reliable in its delivery of Btu.

Owners of commercial buildings and commercial businesses are increasingly seeking ways to use energy more efficiently. Two ways to optimize fuel and electrical savings are through the use of cogeneration and trigeneration.

Replacing a lower or medium efficiency gas- or oil-fired furnace or boiler with a higher efficiency unit will save on fuel consumption costs. What if a customer wants to know how much will be saved? Here is how it is done.

As building owners and facility managers prepare HVAC systems for the peak heating season, the decision to repair or replace aging systems looms large. Contractors can help owners make an informed decision.

Mastering the basics, one step at a time, will make you fully prepared for this industry. It does take time to master the basics, but average people have done it and so can you.

Fabric duct has been used in Europe for over 30 years, but many American contractors have yet to install their first fabric duct project. However, the number of contractors with no fabric duct experience is diminishing as it gains acceptance.

Digital controls have been with us for years, yet those of us who do not regularly work with them are not always aware of their full capabilities.

Typically, with factory coating, coils are immersed in a dip coating process prior to assembly. The problem is, even though they may be coated, the coils must ultimately be soldered into the copper cooling circuit. This results in sections of tubing being exposed to the atmosphere.