A Guide to the Best Practices for Commercial Heat Pump Installation

By: Vishal Patwari, Senior Manager, Budderfly Energy Engineering

Heat pump adoption is on the rise in the U.S. but in the commercial sector has been somewhat stalled. Businesses face unique challenges when it comes to installing heat pumps, yet the energy and cost-saving benefits of heat pump technology are crucial for businesses. In a volatile economic climate and with mounting pressure to address sustainability, businesses stand to gain a lot from replacing their traditional HVAC systems with heat pumps, which can electrify their facilities and cut energy consumption by a significant margin.

There are a few key reasons that commercial businesses have had low rates of heat pump adoption. One of the biggest is that they require specialized knowledge to install, and technicians across the U.S. are lagging behind in commercial heat pump expertise.

At Budderfly, heat pumps are a key part of our energy-as-a-service offering, so our technicians have experience installing them at a wide variety of commercial facilities, with broad variance across facility types and climates. We have seen diverse applications of heat pumps over the years and encountered positive and negative examples of what makes a superior, ultra-efficient installation of this technology. We’ve encountered deficiencies in the design, installation, and commissioning of VRF (Variable Refrigerant Flow) and ventilation systems that resulted in reduced system efficiency, increased operational costs, and elevated risk of premature equipment failure.

More importantly, our team has also learned some best practices to ensure heat pump systems run at their full potential. To help technicians working with this technology and to expedite the adoption rate of this game-changing technology, we’re sharing some of the top insightswe've gained in the field.

System Design and Engineering Best Practices

High-performance outcomes begin at the design phase. At this stage, a few best practices can help make sure the heat pumps are set up for success. It is critical to perform comprehensive load calculations, including diversity factors and to design systems within manufacturer constraints. Ensure proper zoning that reflects operational realities (for example, a restaurant will need to account for the kitchen, dining room, and back-of-house spaces). It is also important to design for serviceability, so future technicians will be able to easily access and work on the units over their lifecycles. Common design issues include heat recovery systems that are improperly applied, limiting energy-saving potential, and inadequate return air design that lead to short cycling and poor temperature control. Factoring these issues can yield better long-term performance results for commercial heat pump systems.

Refrigerant Piping Systems

Refrigerant piping remains one of the most critical—and most frequently mishandled—elements of VRF heat pump system performance. It is common in poorly installed systems to see unsupported piping, improper routing, and sharp bends. Installers need to maintain proper pipe sizing, routing, and slope for oil return. It is also necessary to enforce manufacturer requirements such as the 20-inch rule at branch connections, as incorrect installation of headers and branch connections leads to flash gas and instability. Other best practices include fully insulating refrigerant lines, providing proper mechanical support, and performing pressure testing, evacuation, and precise refrigerant charging. Recurring issues include low charge, non-condensables, and liquid stacking—all linked to installation and commissioning failures.

Air Distribution and Ductwork

Air distribution varies by building, and when not well-managed an negatively impact a building’s comfort and energy saving abilities. Separation between supply and return air paths is essential to prevent recirculation, and airflow must be balanced to maintain design static pressure. Improper unit placement can also cause supply air to short-cycle into return air. Undersized or restricted return ducts significantly reduce system capacity. Sizing ductwork based on required airflow (expressed as CFM per ton) helps prevent these issues. Minimize the use of flex duct and where used, ensure proper support and routing, as poorly installed flex duct leads to airflow loss and inefficiency.

Condensate Management

Improperly installed condensate systems pose an elevated risk of water damage, and our teams have found that use of temporary or residential-grade solutions is common and inadequate. Installers should be sure to utilize gravity drainage wherever possible, maintain proper slope and install P-traps where required, secure and support all condensate lines, and avoid routing condensate through ceiling tiles or unsecured pathways.

Electrical and Controls

Incorrect wiring practices can lead to communication failures in the system, and improper connections and excess wiring lead to intermittent system faults. When wiring a heat pump system, always follow proper communication wiring topology, use manufacturer-approved wiring and installation methods, and ensure proper addressing and system commissioning. These best practices help avoid intermittent system faults and control instability that will require repeated resets and ongoing troubleshooting.

Equipment Installation

Equipment installation quality directly impacts system longevity and performance. Placement of equipment can have an impact in a few different ways. Units should be positioned in a way that maintains clearances for airflow and service access, a factor often overlooked during installation that can result in long-term service challenges. Plus, outdoor units installed in cold climates should be mounted on elevated stands to prevent snow-related failures and defrost issues. Vibration isolation, proper structural support, and secure mounting of both indoor units and piping are foundational requirements. Improvised supports and poor mounting practices compromise system integrity.

Ventilation Integration (ERV/MAU)

Ventilation systems are frequently disabled or improperly configured, which can reduce system longevity. Excess outside air can overload HVAC systems and reduce efficiency. Best practices for ventilation integration include balancing ventilation airflow with HVAC system capacity, ensuring proper filtration on both outdoor and return air streams, and verifying system controls, scheduling, and HVAC integration.

Commissioning and Startup Best Practices

Commissioning is arguably most critical phase of system delivery—and the most neglected. Many systems require re-commissioning due to incomplete startup procedures. Improper charging and lack of verification lead to long-term performance issues. A rigorous startup process includes full piping audits before startup, vacuum decay testing, manufacturer‑calculated system charging, system performance validation and recording of baseline operational data.

Maintenance and Lifecycle Management Best Practices

Lack of maintenance leads to rapid degradation in system performance. It is critical to establish routine maintenance schedules—including filter changes, coil cleaning, belt inspections, and more—and monitor system performance using available analytics. Maintain insulation, clean and replace filters as needed, and fix building envelope deficiencies to preserve system integrity and efficiency over time. Uninsulated curbs and penetrations are consistently identified as major sources of energy loss, directly impacting HVAC control stability and overall efficiency.

Across all sites evaluate by Budderfly, the primary systemic issues we have seen include:

• Inadequate installation practices

• Failure to follow manufacturer guidelines

• Poor or incomplete commissioning

• Improper airflow and duct design

• Lack of ongoing maintenance

These factors collectively prevent systems from achieving expected performance levels. The transition to heat-pump-based systems hinges on the consistent execution of proven engineering principles. By addressing the gaps consistently seen in heat pump applications, organizations can significantly improve system efficiency, reliability, and lifecycle cost performance.

Evaluating Energy Performance

When evaluating heat pump performance, it's important to understand the nuances behind energy savings data. Most energy savings data is reported at the total site level, meaning it reflects reductions across a facility's entire energy consumption, not just the HVAC system. For facilities with high non-HVAC energy loads (quick service restaurants with commercial kitchens, manufacturing facilities with industrial equipment, and others) HVAC represents only a portion of total energy use.

This distinction matters when evaluating energy performance data. A site with a considerable non-HVAC energy load reporting 9% overall energy savings after a heat pump installation may, when you normalize the data to show only HVAC energy consumption, be delivering close to 40% savings on its HVAC system.

Differences in climate can also affect how savings appear on paper. Facilities in regions with more extreme weather (and therefore greater heating or cooling demands) will naturally show a bigger impact from energy-efficient upgrades like heat pumps, while sites in mild climates may show more modest savings—even when the system is performing efficiently.

Rather than evaluating heat pump performance on total site savings alone, ask for HVAC-normalized savings: the reduction in energy attributable specifically to the HVAC system as a share of HVAC's baseline consumption. This figure gives an accurate picture of how the technology is actually performing, independent of the site's overall energy load and performance.