Inside Ductless HVAC Systems

As construction projects grow in size and complexity, ductless HVAC systems are gaining traction. In a world demanding customizable solutions and sustainability, ductless HVAC is flexible and energy efficient.

HVAC contractors who expand their ductless-system capabilities position themselves to win more and bigger projects, but achieving proficiency adds new factors to consider, including costs, installation, risk mitigation, and operational efficiencies. 

This article explores the pros and cons of ductless systems, what makes installation different and how HVAC contractors can become trusted advisers and providers as more projects go ductless.

Considering Ductless: Important Factors

Ductless systems, also known as mini-splits, dispense conditioned air by circulating refrigerants from exterior condensers directly to air handler units installed inside the space being targeted for heating or cooling. 

While project owners and designers have the ultimate say in whether to go ductless or ducted, HVAC contractors can share their expertise, providing guidance regarding major decision points.

Greenbuild vs. Renovation Savings

With new construction, key decision drivers include costs, the heating and cooling needs of individual spaces, and operational efficiencies. In many cases, ductless systems take the lead in all three areas. 

Buildings slated for renovations often have ductwork that can remain serviceable, especially with a relatively simple upgrade to a more efficient air handler. 

While removing ducts from existing structures can be costly, simply abandoning ductwork in favor of ductless systems sometimes pencils out in long-term savings and operational advantages.

Energy Efficiency

Ductless systems aren’t new, but their superior energy efficiency is attracting the attention of sustainability-conscious owners. 

Ductwork loses significant amounts of heat and cooled air. Ductless systems retain the heating and cooling generated, making them a popular, energy-saving choice for many commercial and residential projects.

Type of Project

Ducted systems remain suitable for large spaces with uniform cooling and heating needs, such as gymnasiums or performance venues. 

However, the projects dominating today’s construction landscape include data centers, nursing homes, and healthcare facilities, where different spaces have different heating and cooling needs. Ductless HVAC, with its interior air handlers, allows control of conditions room by room. 

Cost

Unlike residential systems, where the upfront cost of ductless is usually higher than ducted, commercial installations incorporate a range of factors that weigh in the balance. Ductless might look prohibitive until all the costs of ducted systems are added up, including ductwork and labor. 

Flexibility

Flexibility: Heat pumps can give ductless systems heating capabilities as well as cooling. With the further addition of variable refrigerant flow (VRF) technology, different rooms and spaces can be heated or cooled simultaneously, according to their needs and all from one system. 

Hybrid Solutions

For some projects, installing both ducted and ductless systems is the answer. Hybrid approaches can efficiently address the growing need to cool the servers powering a digitizing world. In these scenarios, including small IT rooms, ducted systems maintain uniform conditions that help humans in offices and conference rooms stay comfortable, while ductless systems provide the intensive cooling needed for server rooms.

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The Basics of Ductless HVAC Installation

In many ways, ductless-system installation is simpler and faster than ducted installation, because they dispense with the network of ducts winding through ceilings and walls.

However, ductless demands special attention to several key considerations.

Technician Training

Only specially trained technicians should handle mini-split systems, which use potentially harmful refrigerants flowing through pressurized lines. 

Many — if not most — municipalities require permits for mini-split installation, and HVAC technicians who work with regulated refrigerants are required to obtain EPA Section 608 certification. 

In a labor-shortage environment, finding qualified technicians can be challenging, but trade unions often provide refrigerant-dedicated training for mechanical pipefitters.

System Placement

Ductless systems offer the advantage of compact condenser units, but typically, there’s a maximum distance recommended between condenser placement and wall unit installation. Exceeding manufacturers’ limits can make the system less effective and possibly void the warranty. 

At some sites, the inability to properly place a condenser could eliminate ductless as an HVAC possibility.

Clash Detection

Ductless systems eliminate the need to install large ducts for other trades to work around. 

However, the indoor unit, with its liquid drainage and condensation, shouldn’t be placed above or around electrical equipment. It also requires clear access for airflow and maintenance, so there’s no evading any aesthetic objections by hiding it behind a bookcase. 

Building information modeling (BIM) facilitates placement by redlining the access and no-go zones, making it clear where other elements can and can’t go. 

The Future of Ductless HVAC

Ductless HVAC is having its day as an all-purpose HVAC solution for commercial construction projects. The key to success is maximizing efficiencies and mitigating risks — a matter of marrying HVAC experience with BIM technology to optimize installation of ductless systems that deliver savings, energy efficiency and the power of customization.

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