Energy Efficiency Guide for Colorado Businesses
Recommendations by Sector
Sales floors are the most energy-intensive areas in retail buildings, so they are the focus here. Of course, most retail stores also include warehouse space and some office space, so users should go to those topics for further recommendations. Lighting is the highest energy user in retail spaces (40%), which also contributes to the cooling load. HVAC systems typically account for 35% of energy use and plug loads about 22%. Domestic hot water only consumes about 3%.
Customers are good for business, and “people load” contributes to space heating in winter. However, since people contribute both heat and moisture, the cooling system must work to maintain a comfortable environment during the shoulder months and summer. The challenge is to maintain an attractive, comfortable environment while limiting energy use and peak demand.
Many retails spaces are leased from building owners who are not enthusiastic about improving the energy efficiency of their property when tenants are paying the energy bills. However, it is frequently possible to persuade landlords to make energy-saving improvements a part of long-term lease agreements since these not only improve the property but also save money and make the space more attractive to present and future tenants. Indeed, such measures as lighting retrofits are often good investments by tenants even in the absence of landlord contributions.
Measures that are frequently found to be cost-effective include the following:
- Replace T-12 fluorescent fixtures with T- 8 or T-5 fixtures with electronic ballasts. Bulbs with good color rendering properties for displaying merchandise are widely available.
- Use higher-efficiency spots and floods for illuminating merchandise. Incandescent and halogen lighting is quite inefficient and both produce objectionable heat. In many cases they can be replaced by compact fluorescent fixtures that provide better illumination, are much more efficient, and last from 4 to 10 times longer than incandescent and halogen fixtures.
- Incorporate skylights and photocell controls. In many retail designs, standard 4-foot by 8-foot bubble skylights are used. Usually, a skylight-to-floor area ratio of 1:25 balances daylight with space conditioning requirements. Energy savings and enhanced sales can both result.
- Install and adjust automatic dimming controls to take advantage of daylighting.
- Install LED exit signs.
- Upgrade parking lot lighting to save energy and reduce environmental impacts.
- Install a demand-controlled ventilation system. When only a few people are in a store, energy can be saved by decreasing the amount of ventilation supplied by the HVAC system. A demand-controlled ventilation (DCV) system senses the level of carbon dioxide in the return air stream and uses it as an indicator of occupancy. DCV can save energy during peak cooling periods when many shoppers are at work and occupancy is low.
- Choose high-efficiency packaged A/C units listed by the Consortium for Energy Efficiency in their Tier 2 guidelines (www.cee1.org/com/hecac/ac_tiers/impcttbl.htm).
- Install variable air volume air handling systems with variable speed drives.
- Downsize to a new high-efficiency chiller in conjunction with lighting and other retrofits.
- Use condensing boilers with large turn-down ratios whose efficiencies improve with turn-down.
- Switch over to direct digital controls.
- Install premium-efficiency motors.
- Upgrade the energy management system; optimize settings to reflect usage, respond to changing weather patterns, and control peak electric loads.
- Continuously commission the building.
- Install high-efficiency glazing carefully chosen for each building facade's relation to the sun and other variables. When installing new glazing, choose a product that has high transmission in the visible spectrum (to enhance daylighting within and view from inside and out) but low transmission in the infrared (low solar heat gain coefficient, SHGC) to enhance energy performance during the cooling season.
- Install overhangs to limit direct beam sunlight coming in store windows.
- Install insulation in strategic locations.
- Undertake strategic air sealing, including duct work.
- Install an ENERGY STAR cool roof.
- Use low-energy sleep functions on computers, printers, and copiers.
- Choose ENERGY STAR appliances.
- Ensure building maintenance and cleaning staff are enthusiastic about savings and adopt work habits that support energy efficiency.
- Involve all employees in energy savings efforts, provide efficiency education for work and home, and encourage employee suggestions on energy savings opportunities.
Funding for this Guide provided by:
Recommendations for this and other sectors are available at www.coloradoefficiencyguide.com/recommendations.