Top 5 Consulting-Specifying Engineer Articles, December 26-January 1: NEC 2017 changes, economics of HVAC systems, assessing replacement electrical systems, more

Articles about NEC 2017 changes, HVAC system economics, replacement electrical systems, fan-efficiency rules, and the whole-system approach were Consulting-Specifying Engineer's five most clicked articles from last week, December 26-January 1. Were you out last week? You can catch up here.

By Brana Webb January 3, 2017

Consulting-Specifying Engineer‘s Top 5 most read articles online, for December 26-January 1, covered NEC 2017 changes, economics of HVAC systems, assessing replacement electrical systems, understanding fan-efficiency rules, and reasons to use a whole-system approach. Link to each article below.

1. Previewing NEC 2017 changes

The current version of NFPA 70: National Electrical Code (NEC) is the 2014 edition. Though this version has not been adopted in all jurisdictions, this article reviews a project that is being designed to meet the 2014 code. A few key updates to the NEC in 2017 and their potential impacts to future designs are also highlighted. 

2. Calculating economics of HVAC systems

Codes and standards, equipment efficiencies, energy modeling, commissioning, energy-conservation incentive programs, and lifecycle cost analysis all play into determining the economics of HVAC systems. Included are key aspects a mechanical engineer may need to consider when specifying HVAC systems into new or existing buildings, with a focus on the economic analysis provided to the client. 

3. Assessing replacement of electrical systems

Replacement of electrical systems is a study of economics and risk. Factors including age, safety, reliability, efficiency, and energy costs must be weighed in conjunction with replacement costs and liability risk to formulate and prioritize upgrade plans. A comprehensive cost-benefit analysis study for each electrical subsystem will allow facilities to plan short-term and long-term expenditures for maintenance and upgrade programs for prudent facility reinvestments, replacements, and growth. 

4. Understanding the fan-efficiency rules

Fan efficiency is critical in HVAC and process air systems. The new proposed Department of Energy standard will drive changes in how engineers design air systems to minimize fan energy. 

5. Why engineers should use a whole-system approach for design and construction

Using a whole-system approach to specifying equipment can lead to many benefits, such as improving the building’s energy efficiency. 

This list was developed using CFE Media’s web analytics for stories viewed on, December 26-January 1, for articles published within the last two months.

Brana Webb, production coordinator, CFE Media,