Guide to Reducing Energy Cost through Better Air Management

Executive Summary

Energy costs contribute significantly to industrial and warehouse overhead expenses. MidAmerican Energy, an energy provider in the U.S. Midwest, estimates that the average unrefrigerated warehouse in the Midwest spends over $13,000 per year on electricity and natural gas- with about 23% of that earmarked for heating, cooling, and ventilation. With energy prices near all-time highs and trending higher, there is a need for innovative ways to save electrical energy and reduce cost in industrial facilities.

The energy requirements of a facility are determined by a number of factors, including business process needs, the quantity and efficiency of process equipment and facility lighting, the business’ operating hours, and the number of employees. Independent of operating costs, the climate of the facility’s location plays a key role in determining energy needs. Buildings in regions with more Heating Degree Days (HDD) or Cooling Degree Days (CDD) are expected to use more energy to maintain a comfortable working temperature within their facility.

To maintain a comfortable working temperature, building managers can optimize air management best practices to decrease reliance on expensive HVAC systems and install energy saving high-volume, low-speed (HVLS) fans. These large fans efficiently move air with a low power draw, allowing both conditioned air in the summer and heated air in the winter to be circulated more uniformly throughout the building. This improved air movement results in less HVAC energy use while maintaining or even improving employee comfort.

VividAir has engineered and patented five HVLS and industrial fan products to provide industry-leading performance for energy-conscious facilities. Our white paper guide details a variety of solutions that utilize VividAir fans to reduce energy cost through better facility air management.

Introduction

With electricity costs at near all-time highs and a volatile natural gas market, facility managers are looking for ways to mitigate the impacts of changing prices and control warehouse expenses. The average non-refrigerated warehouse allocates nearly a quarter of its electricity and natural gas spending to maintain a healthy indoor climate.[1] For industrial facilities with air conditioning, or in sectors especially sensitive to energy price fluctuations like manufacturing, transportation, and agriculture, looking for a more sustainable and economical option is important.

In addition to the potential cost savings, many businesses are prioritizing reducing their environmental impact by implementing energy saving technologies. The ENERGY STAR program, a joint program of the U.S. Environmental Protection Agency (EPA) and Department of Energy (DOE) [2], not only certifies energy efficient products, but also energy efficient buildings.[3] Having a competitive ENERGY STAR score is particularly important as a benchmark to demonstrate a company’s commitment to meeting energy efficiency goals and the requirements of the municipality where they operate.[4]

High volume low speed (HVLS) fans offer an efficient way to accomplish both of these objectives, while also prioritizing employee comfort. HVLS fans provide power saving benefits in both summer and winter conditions, allowing facility managers to better manage and mitigate the impact of energy costs on their business. This white paper provides guidance on reducing energy costs in warehouse, industrial, and other large facilities through the innovative air management techniques delivered by HVLS fans.

Problem Statement and Background

Energy costs are high and increasing.

Electricity costs are near all-time highs. The U.S. Bureau of Labor Statistics calculates the current (May 2023) national average at $0.17/kWh – a rate that has nearly doubled over the last 20 years. Energy rates are highly location-dependent, however. Electrical consumers in San Diego, California pay on average $0.48/kWh, almost three times the national average.

The cost of natural gas energy is also on the rise, but over the same 20 year timeframe has shown some volatility. At its current average rate of $1.39/therm, the cost of natural gas is about 40% higher than its 20 year average of $0.97/therm, but during that time has ranged from lows of $0.69 to a high of $1.60.[5]

Unexpected increases in energy cost can make budgeting and planning extremely challenging for building managers, and the high cost of electricity and natural gas may require diverting capital from other potential business investments.

Energy demand is high in warehouses and industrial spaces.

The U.S. Environmental Protection Agency’s ENERGY STAR Portfolio Manager program tracks and collects data from a variety of different business types. The median non-refrigerated warehouse in the Portfolio Manager program is approximately 36,000 square feet and operates 55 hours per week with density of 0.6 workers per 1000ft.[2] Within this average facility, there are a number of variables that could contribute to increased or decreased energy use, including the quantity or efficiency of warehouse equipment, lighting, or business activities.[6] Their January 2015 trend report correlates increased energy use in non-refrigerated warehouses with greater numbers of workers per square foot, as well as with increased operating hours.

MidAmerican Energy, an energy provider in the U.S. Midwest, estimates that the average non-refrigerated warehouse in the Midwest spends over $13,000 per year on electricity and natural gas- with about 23% of that earmarked for heating, cooling, and ventilation. While the majority of electricity spending is on lighting (41%), nearly all natural gas use is for space heating (94%).[1]

Industrial, manufacturing, and warehouse facilities that utilize air conditioning would have a significantly greater electricity cost than average. Both high heating and high cooling costs, however, present an opportunity to optimize energy use with better air management.

Energy needs are location dependent.

Independent of the needs of the business and its associated activities, the warehouse location’s climate also affects energy usage. The U.S. Energy Information Administration quantifies this need in “degree days,” a measure of how cold or warm a location is, and it’s an important component of benchmarking energy efficiency.[7] A degree day compares the mean (the average of the high and low) outdoor temperatures recorded for a location to a standard temperature, typically 65°F in the United States. The more extreme the outside temperature, the higher the number of degree days.

Degree days are characterized as Heating Degree Days (HDD) or Cooling Degree Days (CDD), with HDD a measure of how cold the location was, and CDD how warm. In 2021, the West North Central region (ND, SD, NE, KS, MN, IA, MO) had the highest number of HDD at 6058, and the West South Central region (TX, OK, AR, LA) with the highest number of CDD at 2643.[8] The median non-refrigerated warehouse in the Portfolio Manager program measured 4483 HDD and 1056 CDD, with more heating degree days correlated to more energy use.[7] The energy required to maintain a comfortable indoor working environment for employees can be high when outdoor climates are extreme.

Facilities can calculate their energy use intensity for benchmarking or improvement.

Energy Use Intensity, or EUI, is a measure of the energy efficiency of a building’s design and/or operations. The American Institute of Architects California suggests considering EUI as the “miles per gallon rating of the building industry.”[9] EUI is expressed as energy per square foot per year. It’s calculated by dividing the total energy consumed by the building in one year (in kBtu or GJ) by the total gross floor area of the building (in ft2 or m2).[10]

EUI has become a standard energy benchmark, and as such, data exists for comparison to a variety of building types, allowing managers to see how their buildings rank compared to peers. The median source EUI of a distribution center or non-refrigerated warehouse in the U.S. is 75 and 81 kBtu/ft2, respectively. For warehouses, EUI ranges from less than 50 to more than 600 kBtu/ft2, with those at the 95th percentile using nearly 21 times the energy of those at the 5th percentile.[6] Facilities with an above-average EUI can almost certainly benefit from optimized energy management practices.

Reducing energy cost can benefit corporate environmental, social and governance (ESG) initiatives.

EUI and indoor environmental quality (IEQ) are two key measures for evaluating the operating performance of green buildings.[11] The EPA’s ENERGY STAR program is one of the most widely recognized applications of EUI, where buildings are graded on a 1-100 scale for their overall energy efficiency. While many large organizations have been using ENERGY STAR to track their energy usage proactively, some municipalities are now requiring buildings to be benchmarked.[12] For non-refrigerated warehouses, the mean facility has an ENERGY STAR score of 52, leaving a significant amount of room for improvement.

Solution: High-volume Low-Speed (HVLS) Fans

High-volume low-speed fans offer an innovative solution to the high energy costs common in large industrial buildings. HVLS fans are large fans that are engineered to create a slow-moving column of air that circulates throughout the room. This gentle, constant airflow helps to create a more consistent temperature and humidity level throughout the space. HVLS fans can reduce the energy required to keep employees comfortable, especially if your facility uses air conditioning in the summer or requires heating in the winter.

VividAir engineers and manufactures patented HVLS and industrial fans with innovative designs that improve employee comfort while increasing energy efficiencies. The Z-Tech, Z-Tech 3, and ConZumer HVLS fans generate industry-leading air flow with minimal power requirements. The Z-Chill HVLS fan and diffuser system economically spot cools or heats unconditioned space within a facility. The Taz industrial fan efficiently moves air in challenging spaces for targeted cooling.

Each of these innovative designs provide a blueprint to reducing energy cost. A facility manager looking to reduce energy cost through better air management can consider taking the following steps:

Replace traditional fans with HVLS fans.

HVLS fans are more energy efficient than traditional industrial fans. A 20-foot Z-Tech HVLS fan can move approximately 125,000 cubic feet per minute (cfm) of air – equivalent to 6 or more standard fans – with a 1 to 2 horsepower motor. The typical operating cost of an HVLS fan is just $0.29 per hour (at $0.17 per kWh electricity rate), but the benefits aren’t just in energy cost savings.

Traditional floor fans have a limited cooling capacity, and may not be able to cool large warehouses or spaces with high heat loads on their own. Long fan cords and extension cords can present tripping or fall hazards when not properly managed. Even traditional panel-aisle and basket fans can be replaced with power saving VividAir Taz fans, with 1 Taz fan able to replace up to 4 panel-aisle fans or 8 basket fans with half the power requirement.

Set the temperature higher when using air conditioning.

For commercial and industrial spaces with air conditioning, installing HVLS fans can offer energy saving benefits. HVLS fans take advantage of the evaporative cooling effect, the cooling sensation that’s created when water evaporates. The air movement created by HVLS fans helps employees feel cooler while the facility temperature remains the same. This could allow the thermostat to be set up to 7 degrees higher in the summer without sacrificing employee comfort. For each set degree difference, the Department of Energy estimates a cost savings of up to 3%, creating the potential to lower the cost of air conditioning in your facility by 20%.[13]

In addition to the employee comfort benefits, HVLS fans can increase the effect of energy efficient air conditioning by distributing the conditioned air more consistently through the space. By destratifying the air layers that naturally form in large facilities, pockets of stagnant hot or cold air can be reduced and allow the temperature setpoint to be achieved more quickly. Running HVAC equipment less not only contributes to energy cost savings, but also reduces the equipment wear and potential for costly repairs.

Reduce heating system run time.

Ninety-four percent of a warehouse’s natural gas cost is spent on space heating. For facilities in locations with a high number of HDD, maintaining a comfortable temperature in your facility can come at a considerable expense. Warm air naturally collects near the ceiling and creates a temperature gradient that can lead to excessive heating requirements when air near the warehouse floor remains cold.

VividAir’s patented HVLS fan designs allow for true reversibility in winter months, so that facilities can reclaim the warm air that floats up to the rafters. In a process known as destratification, an HVLS energy-saving fan will draw heated air down and mix it with cooler air that settles near the floor. While the HVLS fan is operating, it’s possible to turn the thermostat down and maintain warm temperatures while reducing energy consumption and saving money. A 2014 study by the Nicor Gas company found that a facility utilizing HVLS fans cycled their heating system less frequently, resulting in a 21.4% reduction in energy use.[14]

Eliminate or reduce dehumidifiers.

Whether your facility is located in a humid climate or your manufacturing processes produce excess humidity in the air, HVLS fans can eliminate or reduce the need for higher-energy dehumidifiers. By constantly moving more air at a slower rate, HVLS fans raise the evaporation rate of moisture in the air as warm air mixes with cooler air.

HVLS fans eliminate “sweating slab syndrome” problems that create floor dampness and potential safety issues. While energy use is reduced, safety, comfort, and environmental quality is improved.

Spot cool with air conditioning only where needed.

HVLS fans can be used in conjunction with zoning strategies in larger spaces. Facility managers can cool or heat specific areas based on equipment or occupancy needs by strategically placing fans to create air movement zones. This allows for more precise temperature control and reduces energy consumption by conditioning only the necessary areas.

VividAir’s patented Z-Chill fan and diffuser system is an ideal solution for spot cooling and heating. By dispersing conditioned air and/or forced heat evenly over Z-Tech fan blades, the Z-Chill provides over 45,000 ft2 of destratification coverage while reducing heating and cooling energy costs.

Build for sustainability in building design and construction.

Incorporating HVLS fans into the initial design or retrofitting of a building demonstrates a commitment to sustainable practices. Businesses, schools, and manufacturing facilities can showcase their dedication to reducing their environmental impact and potentially improve their ENERGYSTAR rating by adopting energy-efficient and environmentally friendly technologies like HVLS fans.

Conclusion

With rising electricity costs and a volatile natural gas market, facility managers are seeking ways to control warehouse expenses and mitigate the impact of changing prices. Warehouse spending on electricity and natural gas for maintaining a comfortable indoor climate is significant, especially in sectors sensitive to energy price fluctuations. To achieve cost savings and environmental sustainability, businesses are turning to energy-saving technologies, including high volume low speed (HVLS) fans. HVLS fans not only prioritize employee comfort but also offer power-saving benefits throughout the year, enabling facility managers to better manage energy costs.

Contact VividAir

VividAir is a high performance commercial HVLS fan manufacturer dedicated to the science of better air. Our patented designs include the Z-TechTM blade, a stepped symmetrical fan blade that dramatically reduces frictional resistance and drag while greatly increasing air displacement and thrust. The Z-Tech blade design provides an industry leading coverage area that’s 30% greater than the competition.

References

[1] Save energy and money at your warehouse [Internet]. Midamericanenergy.com. [cited 2023 Jun 16]. Available from: https://www.midamericanenergy.com/warehouse

[2] Energy star® [Internet]. Energy.gov. [cited 2023 Jun 18]. Available from: https://www.energy.gov/eere/buildings/energy-starr

[3] ENERGY STAR certification for buildings [Internet]. Energystar.gov. [cited 2023 Jun 18]. Available from: https://www.energystar.gov/buildings/building_recognition/building_certification

[4] Benchmarking and energy efficiency rating [Internet]. Nyc.gov. [cited 2023 Jun 24]. Available from: https://www.nyc.gov/site/buildings/codes/benchmarking.page

[5] Bls.gov. [cited 2023 Jun 16]. Available from: https://www.bls.gov/regions/midwest/data/averageenergyprices_selectedareas_table.htm

[6] Warehouses N-R. Energy use in non-refrigerated warehouses [Internet]. Energystar.gov. [cited 2023 Jun 16]. Available from: https://www.energystar.gov/sites/default/files/tools/DataTrends_NRWarehouse_20150129.pdf

[7] Energystar.gov. 2021 [cited 2023 Jun 16]. Available from: https://portfoliomanager.energystar.gov/pdf/reference/ENERGY%20STAR%20Score.pdf?_gl=1*hwyjk2*_ga*NzkxNjA4NzA4LjE2ODc2NjU5OTU.*_ga_S0KJTVVLQ6*MTY4Nzk0OTQ2OC41LjEuMTY4Nzk1MDAzNi4wLjAuMA

[8] Degree-days – U.S. Energy Information Administration (EIA) [Internet]. Eia.gov. [cited 2023 Jun 18]. Available from: https://www.eia.gov/energyexplained/units-and-calculators/degree-days.php

[9] California AIA. Energy use intensity (EUI) [Internet]. Aiacalifornia.org. [cited 2023 Jun 18]. Available from: https://aiacalifornia.org/energy-use-intensity-eui/

[10] What is Energy Use Intensity (EUI)? [Internet]. Energystar.gov. [cited 2023 Jun 18]. Available from: https://www.energystar.gov/buildings/benchmark/understand_metrics/what_eui

[11] Geng Y, Lin B, Zhu Y. Comparative study on indoor environmental quality of green office buildings with different levels of energy use intensity. Build Environ [Internet]. 2020;168(106482):106482. Available from: https://www.sciencedirect.com/science/article/pii/S0360132319306948

[12] The future of energy efficiency: EUI and predictive maintenance [Internet]. Facilities Management Advisor. 2022 [cited 2023 Jun 24]. Available from: https://facilitiesmanagementadvisor.blr.com/energy-management-and-lighting/the-future-of-energy-efficiency-eui-and-predictive-maintenance/

[13] Energy tips for commercial buildings [Internet]. Doee.dc.gov. [cited 2023 Jun 24]. Available from: https://doee.dc.gov/service/energy-tips-commercial-buildings

[14] Douglas Kosar, Gary Cushman. Emerging Technology Program 1026: Destratification Fans Public Project Report – Executive Summary. 2014 October. https://www.nicorgas.com/content/dam/southern-co-gas/shared/pdf/business/rebates-and-assessments/public-project-reports/Destratification-Fans.pdf