Energy Code Guide for Commercial Construction in Utah

2015 International Energy Conservation Code (IECC)

C103.2 – 103.3 Construction Documents All thermal performance values and factors must be identical and included on:

• Plans
• Specifications
• Energy Compliance Documents
• HVAC Design Calculation

Utah Climate Zones by County

IECC Compliance Options Prescriptive – Includes UA Trade-off OR Total Building Performance

2015 IECC Prescriptive & Trade-off Options Comply with requirements of:

• C402 – Envelope
• C403 – Mechanical
• C404 – Service Water Heating (SWH)
• C405 – Lighting

AND Pick 1 of 6 Additional Efficiency Options:

• C406.2 – Increase HVAC efficiency
• C406.3 – Reduced Lighting Power Density
• C406.4 – Enhanced Lighting Controls
• C406.5 – On-site Renewable Energy
• C406.6 – Dedicated Ventilation Systems
• C406.7 – High Efficiency SWH

ENVELOPE

C-402.2 – 402.4 Specific Envelope Requirements

• Continuous insulation
• Frame and Mass walls
• Floor and Slab-on-grade floors
• Roof reflectance – Climate Zone 3 only
• 30% of gross wall area limit on fenestration
  • Increase to 40% with daylight responsive controls
• Minimum skylight area for spaces > 2500 ft2
  • 3% of gross roof area limit on skylights
• Increase to 5% with daylight responsive controls

2015 IECC Prescriptive Option Opaque Thermal Envelope Requirements Comply with: Table C402.1.3 – R-Value Method OR Table C402.1.4 – U-Factor Method AND Table C402.4 – Fenestration U-Factor and SHGC

Trade-Off Option (Prescriptive alternate)

• C402.1.5 – Component performance alternative
• Perform UA calculation with COMcheck OR
• Equation 4-2

Mandatory Requirements C402.5 Air Leakage-Thermal Envelope Comply with C402.5.1 through C402.5.8 OR test at 75Pa, to a leakage ≤ 0.40 cfm/ft2

• Air Barriers – construction, materials, assemblies
• Fenestration leakage
• Rooms containing fuel burning appliances
• Vestibules
• Air intakes, exhaust openings, stairs & shafts

2015 IECC Performance Option Comply with requirements of:

• C407 – Total Building Performance
• C402.5 – Air Leakage
• C403.2 – Provisions applicable to all mechanical systems
• C404 – SWH
• C405.2, C405.3, C405.5 & C405.6 – Lighting AND C401.2(3)- Building Energy

MECHANICAL Applies to all heating, cooling, ventilation, walk-in coolers & freezers & refrigerated warehouses

C403.2 Mandatory Requirements

• Equipment sizing
• Equipment performance – efficiency
• Control requirements – set points
  • Snow melt
  • Zoning
  • Freeze protection
  • Economizer Fault Detection
  • Boiler reset
• Ventilation
  • Demand Controlled ventilation
  • Enclosed parking ventilation
  • Energy Recover ventilation
  • Kitchen Exhaust
• Duct Sealing & Insulation
• Piping insulation
• Fan motor horsepower & efficiency
• Heating outside a building – controls
• Comprehensive refrigeration/freezer requirements

C403.3 Economizers

• Required for cooling system ≥ 54,000 Btu/hr
• Controls and design dependent on use

C403.4 Hydronic and Multi-zone VAV system places limits on reducing airflows to minimums, re-heat, & fan horsepower

C403.4.5 Heat Recovery for Service Water Heating For buildings with high continuous water demand (example – hotel) > 6,000,000 BTU/hr, use A/C rejection heat

C404 Service Water Heating

• Equipment performance
• Higher efficiency where demand is high
• Heat traps & piping insulation

C404.5 – Efficient piping size and length C406.6 – Heated water re-circulation

• Controls, temperature

C404.9 – Pools and Spas

• Controls, pumps & covers

LIGHTING

C405.1 Controls & Maximum Lighting Power Density for Interior & Exterior Lighting

• Occupancy sensors
• Time switch controls
• Lighting reduction controls
• Daylight Responsive controls
  • Reduce artificial lighting automatically
• Daylight zones – independent control in areas
  • Windows & skylights
• Exterior lighting automatic operate per available natural light

C405.4 Interior Lighting Power Total connected interior lighting power (TCLP)

• Building area methodOR
• Space by space method
• Tables for both methods based on use of area or space
• Additional allowances for specific lighting functions

C405.5 Exterior Lighting Power

• Lighting power allowance based on space; parking, walkway, entry etc.
• Trade-offs allowed between some space types
• Total allowable lighting based on area
  1. Developed forest, park – rural
  2. Residential
  3. Other
  4. High activity commercial

C405.8 Electrical Motors Nominal full load efficiency per table, based on horsepower

C405.9 Vertical Horizontal Transportation Systems & Equipment

• Elevators, escalators and moving walks
• Light limits elevators
• Control to reduce speed when unoccupied
• Regenerative drive down operation escalator

C408 System Commissioning

• Must have commission plan at design stage
• Air and water balance
• Functional testing sequence of operation
• Control calibration of mechanical, SWH and lighting
• Final Commissioning Report