What to expect in the 2015 IECC Commercial Provisions, Part II

By Ryan Meres, IMT

The first installment of this article was published in the May 2015 edition of The Decoder. Part I discussed the improved provisions for commissioning, HVAC equipment, water heating, and lighting. In this article, we’ll cover some important changes to:

  • Additional efficiency package options
  • Rooms with fuel burning appliances
  • Walk-in coolers and freezers
  • Refrigerated display cases
  • Equipment buildings
More Efficiency Package Options

The 2015 IECC now has six options for designers to choose from under Section C406 – up from only three options in 2012. The new options include: enhanced lighting controls, a dedicated outdoor air system, and high-efficiency service water heating. The addition of these three new options will give designers more flexibility in meeting the additional efficiency requirement.

Rooms Containing Fuel Burning Appliances

The 2015 IECC adds a new requirement that only applies to open combustion space conditioning fuel-burning appliances located in climate zones 3-8. Where an atmospherically vented appliance is located inside the building’s thermal envelope and combustion air is provided through open ducts (often called high/low vents), the appliance must be enclosed in a room that is isolated from inside the thermal envelope. These types of enclosures are often called combustion closets and they must be insulated and sealed the same as any other exterior wall assembly. Fireplaces and stoves complying with the International Mechanical Code and the International Building Code do not have to comply. Direct vent appliances with both intake and exhaust pipes installed continuous to the outside are also exempt from this requirement.

Walk-in Coolers/Freezers and Refrigerated Display Cases

There are a suite of new requirements for walk-in coolers and freezers in the 2015 IECC. The new provisions include four new definitions for: refrigerated warehouse coolers, refrigerated warehouse freezers, walk-in coolers, and walk-in freezers. The new provisions vary depending on whether or not the cooler or freezer is assembled or constructed on-site or off-site. New requirements address insulation, doors, lighting, and fan motors.

The new code also includes provisions for refrigerated display cases. The requirements include time-switch controls to turn off lights during non-business hours and motion sensor controls to reduce lighting power after three minutes without sensing any motion.

Equipment Buildings

A new section is included in the 2015 code to address an exemption from the building thermal envelope provisions for certain buildings designed to house equipment. These types of buildings:

  • Are designed to house electronic equipment,
  • Are not more than 500 square feet,
  • Have a heating system capacity not greater than 17,000 Btu/hr or 5 kW,
  • Have a heating thermostat set-point restricted to not more than 50 degrees F,
  • Have average wall and roof U-factors less than 0.200 in climate zones 1- 5 and 0.120 in climate zones 6- 8,
  • Comply with the roof solar reflectance and thermal emittance requirements provisions for climate zone 1.

Equipment buildings that meet all of these provisions are exempt from the building thermal envelope requirements of the IECC. The long-standing “low energy buildings” exemption is also maintained in the new code.

Although many states are just starting to consider the 2015 codes for adoption, it’s already time to begin thinking about the 2018 IECC. All code change proposals for the 2018 IECC are due to the International Code Council in early January. By the end of 2016, the next version of the IECC will be finalized. If you’d like your voice heard and be involved in the code development process, please contact Ryan Meres at the Institute for Market Transformation: ryan@imt.org.