Tag Archives: Retail Store Design

Refrigeration-veggies up close

Control System Strategies Save Money by Miguel L. Purdy, P.E.

How much do you spend each month or year to keep your perishables fresh?   From meats to dairy and frozen foods, to fresh produce and floral, it has been estimated to that between 30% and 50% of the electricity used in food retail is consumed by the refrigeration system.  Ambient conditions that differ from the original design and equipment selection conditions adversely affect the energy used in refrigeration.  Then, other inefficiencies creep in over time, such as dirty coils, burned up fan motors, etc., all the while driving up energy costs.  Systems that were put in as the state of the art systems a few years ago must be refined, tweaked, managed, updated and replaced on a regular basis because of newer, more efficient control schemes that were not available at the time of installation.

Reset First

What is the first step to improving your refrigeration system efficiency?  Well, it is not upgrading or replacing the control system.  The first step is system recommissioning.  Over time, with service calls and owners keeping the system in operation, your systems drift away from the original specifications and set points.  Recommissioning resets all of this and gives you some level ground to work from when looking at the controls system.

Establish Control Strategies

The next step is where monitor and control systems including energy management system come into play.  There are many new technologies that help automate refrigeration control, monitoring and maintenance scheduling.

Floating Suction Pressure Control

Adjusting and maintaining suction pressures allows the system pressure to float above established set points and maintain case or walk-in temperatures.  This is called Floating Suction Pressure Control (FSPC).  For each 1 PSI increase in suction pressure, it is possible to save 2% in compressor power.  The control systems read the systems temperatures and pressures then adjust the set points to ensure that the refrigerant leaving the coils reach the superheat design parameters.

Floating Head Pressure Control

An additional control strategy is reducing the compressor discharge pressure or head pressure.  This strategy is known as Floating Head Pressure Control (FHPC).  By allowing the control system to reduce the head pressure, the system could save as much as 0.5% per PSI reduction.  At least one study found 14% savings of combined compressor and condenser energy consumption for floating head pressure controls with variable frequency drives.

Load Shredding

Control systems do a great job of making the system operate more efficiently, but it can also perform other cost saving measures for your store.  This is where load shedding comes into play.  Suppose there are some functions that are not required to operate during a peak load time of day, such as anti-sweat door heaters, these loads can be turned off for that period of time.  That will not only save some energy, but more importantly, it will reduce the electrical consumption at higher rate times.  Control systems also can coordinate different aspects of the refrigeration system so some large loads do not operate at the same time, if possible, thus reducing the increased demand charges.

Unified Systems

Selecting the right energy management and control system can also unify other systems besides refrigeration, such as lighting and HVAC.  A unified energy management and control system allows the building HVAC management system and the refrigeration control system to work together to keep the systems from fighting over the temperature and humidity conditions in the space.  It can control the lighting within the store to conserve energy when spaces are unoccupied and when the store is closed, or there is less traffic.

Approach to Control System Upgrades

The key to a successful upgrade of any refrigeration system comes from a thorough, front-end engineered approach.  The methodology for the upgrade can be in the form of 1) a phased migration, 2) complete system replacement, or 3) a system upgrade. An important point to remember is that any new user interface must communicate with any existing controllers on a continuous basis.

A phased migration is often the best approach to large scale systems such as large grocery stores.  This approach eliminates risk of system failures or inoperable systems for any period of time, while providing a fallback position with the existing control system, should a failure occur.  While phased migration does have its drawbacks in terms of cost and time, the offsetting benefits include reduced risk and less downtime.

The approach of control system upgrades or complete replacement offers benefits which include: 1) increased asset protection, 2) increased reliability, 3) improved efficiency, 4) faster information access, 5) better interface functionality, 6) improved component communication, 7) reduced service and implementation costs, and 8) lower component costs over legacy systems.

Significant savings are possible

Some controls manufacturers have stated that controls systems can save at least 15% on the electric bill due to better capacity control, set point shifting, scheduling, load shedding and enterprise wide energy management.  The payback for such systems can be 1½ years through energy savings alone, not to mention the reduction in unplanned maintenance calls.

Could your facility use an extra $35,000[1] added to the bottom line each year?

One study found in one of the largest supermarket chains, a survey of 50 stores showed the majority had control systems but that the control strategies were not implemented correctly.   These misgivings provide an opportunity for savings of up to 335,000 kWh annually per site. This opportunity to save money was hidden because the building operators believed they already had the full benefits of controls.[2]

Control systems have come a long way over the last few years.  Is your system doing all that it can for you?  Are you missing out on significant operational savings due to your current control system, or maybe just from the control scheme?  A small investment could allow you to reap large paybacks to the bottom line.

The first step to improve your operational costs is to contract with a commissioning agent or firm to conduct a systems commissioning, then work with an experienced controls engineer to develop the controls system strategy that is configured to best serve your system needs.

###

Miguel Purdy, P.E. is a licensed mechanical Engineer who has over 25 years of refrigeration system engineering design expertise.  Miguel serves as the Program Manager for Refrigeration at HFA can be reached at Miguel.Purdy@HFA-AE.com or 479-273-7780.


 

1 Based on 335,000 kWh x $0.1045/kWh = $35,007.  National average electricity cost = $0.1045/kWh

[2] Supermarket Controls and Commissioning: Uncovering Hidden Opportunities, Diane Levin and Lawrence Paulsen, Portland Energy Conservation, Inc., 2006 ACEEE Summer Study on Energy Efficiency in Buildings.

Engineering a Meaningful Place

We sat down with A/E Firm HFA to ask about the importance of integrating engineering into a good architectural design.

Q: What is the role of engineering when designing a new space?

A: The architect creates the space with the needs of the client in mind, while it’s the challenge of the engineer to make the space functional, comfortable and safe. One of the engineer’s main goals is to design the most optimal use of the space.

“Successful design integrates architecture and engineering into a holistic space.”

DSC_0221

Q: What’s the biggest advantage of HFA being an integrated A/E Firm?

A: Communication. The HFA design team all work in the communication to stimulate creative design solutions. Truly integrating an A/E firm is like designing a good space, you have to understand how the disciplines work together to create the holistic experience for the end-user. In this scenario, our clients are the end-user.

Shreve_150311_0017

Q: How does that integration help in creating meaningful places?

A: Any designer can create a space, but great spaces happen when architects and engineers are working together to optimize it for the human experience. That’s the end goal of any project. Good space design is about the way it makes you feel when you experience it, and we want to create a meaningful place for all to enjoy!

Mar-Apr_CCR Ad-Open House

HFA Ranked Top 5 by Architectural Record

Arch Record List

Architectural Record has ranked HFA the 5th top design firm in the nation for the Retail Market.

As a full service architecture and engineering firm, HFA continues to be a leader in Retail Store design across the United States.

 

Designing for the Customer Experience

We were interviewed about the impact of design on retail. Here’s what we had to say:

Q: Retail brands work tireless hours defining their image, how do you encompass their image into the space you’re creating?

A: For us it’s about a deep connection with the client. We first try to understand their business philosophy. We want to know why they’re in business. Then we immerse ourselves into their brand, so we can become the customer. The goal is to design a space that works for the end-user — their customer.

Shreve_141222_0153

 

Q: Creative Solutions, Meaningful Place.. What does that mean? And why did you choose it as your mission?

“The goal is to design a space that works for the end-user”

A: It means we aren’t just in business to design buildings. We want to create spaces that touch your heart and to experience the space in a meaningful way. We chose it because that’s how we want our team members to design and feel.

Q: Retail brands these days like to roll-out full remodels, how do you manage those projects?

A: The key is understanding the client and their customers. Once we fully understand their program, we use the techniques learned in our 25 years of retail to efficiently design every store, whether it’s 5 stores or 500.

View HFA website

Here’s the original article as published in Commercial Construction & Renovation Magazine:

Jan-Feb_CCR-Ad-Open-House-02