Saving Money in Self-Storage Design: A Focus on MEP (Mechanical, Electrical and Plumbing) Engineering

Self-storage development is still on the rise, but with expenses for nearly everything also going up, owners and builders are very focused on budget. The engineering of today’s facilities, which includes the mechanical, electrical and plumbing (MEP) systems, pose unique challenges but also opportunities to create more energy- and cost-efficient sites.

While it’s your engineer's responsibility to adhere to local and state building codes, ensure energy efficiency, and maintain safety standards, they must also be strategic and selective in their choice of equipment and materials. This is crucial because return on investment (ROI) can be significantly impacted by MEP design. Let’s look more closely at the systems involved and ways to ensure a more profitable project.

HVAC

Self-storage HVAC (heating, ventilation and air conditioning) design is contingent on several factors including project location, climate zone and building-envelope insulation. To determine the appropriate tonnage of your AC units, you must consider each of these variables. Typically, self-storage requires 1,200 to 1,800 square feet per ton of cooling capacity. The insulation standards stipulate a minimum of R-19 for exterior walls and R-30 for the roof, though these values can vary based on climate zone and window coverage.

While split heat-pump systems are a popular choice, there are other options. Packaged units, which contain both heating and cooling components in a single, compact product, are advantageous for their ease of installation and maintenance; however, they may have limitations in terms of capacity and energy efficiency compared to split systems.

There’s also the choice between gas and electric. Gas equipment may have lower operational costs, especially in regions with cheaper natural gas; plus, they provide more effective heating in cold climates. However, they require venting and combustion air provisions, which can add complexity and increase installation cost. Moreover, gas may not be as energy-efficient as electricity in some cases.

Electrical HVAC, including heat pumps and furnaces, can be more straightforward to install and maintain. They’re often more energy-efficient and don’t require combustion-related infrastructure or gas lines. Yet, they may result in higher utility bills, especially in areas with expensive electricity. Adding solar panels can help, but it’ll be necessary to run a cost-benefit analysis.

Finally, you’ll have to decide where to place your HVAC equipment. Roof-mounted systems can free up valuable ground space, enhance security and reduce noise; however, they may be more challenging and costly to install and maintain due to limited access. Ground-mounted systems are easier in this regard but take up space that could otherwise be for other uses. Ultimately, these decisions should be based on the specific needs and constraints of the self-storage project.

HVAC Pro Tips

Reduce complexity. Depending on your building-code requirements, consider using multiple fan coils. When doing so, it's advisable to keep them under four tons or less to avoid the need for an economizer, which will add complexity to the system and increase initial costs.

Consider fabric ductwork. Some companies offer innovative and cost-effective fabric alternatives to traditional metal ductwork. This product not only provides precise and efficient HVAC for virtually any building application, it can offer better indoor air quality and control over the growth and spread of bacteria and mold. It’s also easy to clean and can even be laundered.

Installation of fabric ductwork is simple. It involves tension cables running from one end of the corridor to the other, and a lock-down strap attached to one end of the fabric duct to the top plenum on the indoor air handler. Then the fabric ducting is clipped to the tension cable and zipped up. This results in air being evenly distributed along the entire length of the duct through laser-cut precision air holes.

Electrical

In self-storage, efficient electrical engineering demands careful placement of switchgear and subpanels to minimize power-transmission distances and trenching. Switchgear should be centrally located near the utility transformer, reducing energy losses and enhancing voltage stability. By strategically situating subpanels closer to self-storage units and along main pathways, engineers can reduce the overall length of conduit runs, trenching and associated costs while maintaining effective power distribution and ensuring compliance with electrical codes and standards.

Additionally, individual disconnect switches should be positioned at each building to isolate power in case of emergency and facilitate maintenance. Grounding systems for separate buildings must also be implemented to ensure safety and compliance with regulations. This strategic approach optimizes power distribution while reducing installation costs and enhancing reliability.

Electrical Pro Tips

Use LED exterior lighting. It may sound simple, but using LED wall-pack fixtures for exterior lighting can cut costs significantly. They consume less electricity than traditional lighting, resulting in lower energy bills. You can improve savings further by adding controls such as motion sensors or photocells, which allow for automatic activation and deactivation based on occupancy or ambient light levels.

Use interior motion sensors. Integrating motion sensors into your self-storage corridor lighting is energy- and cost-efficient. When someone walks down the hallway, only the lights in their immediate path are activated vs. the entire corridor or floor. Additionally, battery-powered emergency lighting can be placed at every third or fourth fixture down the stretch to remove the need for “bugeye” fixtures and the additional wiring involved with their installation.

Select the proper voltage. An electrical service size of 600-amp, 480-volt/277 three phase and four wires is equal to roughly 1,200-amp, 208-volt/120-volt three phrase and four wires. On a large site, 480-volt power makes sense for longer runs, lower voltage drop and smaller wires, resulting in a more efficient system. However, when it comes to a single building with multiple floors, it’s better to run on 208-volt power to avoid having multiple step-down transformers and different panels for various voltages. Even lighting and security gates can be run on 277-volt or 120-volt, so it can support either system.

Be strategic about receptacle placement. Selective placement of general receptacles can make for easier maintenance. Placing them on the ceiling and next to fan coils serves a dual purpose of allowing for HVAC-equipment maintenance and restricting customer access. If the goal is to prevent tenants from plugging in their own equipment and appliances, these receptacles can be lockable.

Plumbing

Plumbing design for self-storage often differs significantly from that of other commercial properties due to there being minimal requirements. These facilities typically have one or two all-gender, single-occupancy restrooms in the office area, with perhaps one or two additional per floor at most. These are typically designed to meet only basic hygiene needs for customers and staff.

Some facilities include site plumbing and hose bibs along the exterior for maintenance and cleaning purposes. In particular, operations catering to boat/RV storage might include a wash station. Ideally, this should be near the office and as close to the water meter as possible to minimize plumbing runs and reduce water-pressure issues.

Focus on ROI

MEP system design for self-storage facilities requires a comprehensive understanding of building codes, climate conditions and energy efficiency. To ensure the best cost and energy efficiency on your project, thereby improving ROI, consider the factors and tips above.

Ryan Labus is business-development leader for Pro Engineering Consulting, an MEP engineering firm that specializes in self-storage, warehouse and manufacturing facilities and more. Prior to joining the company, he was an assistant project manager for commercial general contractors. He uses his combined experience to help clients define and meet their project goals. To reach him, call 949.525.6578 or email [email protected].