What Is a Hydronic HVAC System?

This system circulates heated water through tubing embedded beneath the floor surface. The warmth rises evenly, creating a consistent and comfortable indoor environment without noisy fans or ductwork. It's especially useful in spaces like offices, lobbies, or multi-use commercial buildings where quiet, low-maintenance heat is preferred. Radiant floor systems also improve indoor air quality since they don’t blow dust or allergens around, and they help reduce energy costs due to their efficient heat distribution and lower operating temperatures.

Radiators are one of the most traditional forms of hydronic heating. They work by transferring heat from hot water or steam into the surrounding air through metal fins or panels. In commercial buildings, modern radiator systems are often redesigned to be more compact and efficient, making them easy to integrate into existing layouts. Radiators deliver steady, localized heating and can be individually controlled in different zones, which adds flexibility and helps reduce energy waste in underused areas.

Fan coil units (FCUs) use a heat exchanger and a fan to control air temperature in individual rooms or zones. Water flows through coils inside the unit, and the fan distributes either warm or cool air into the space. FCUs are common in hotels, offices, and large multi-tenant buildings due to their zoned control and compatibility with both heating and cooling. They’re also easy to maintain and can be configured for vertical or horizontal installation, depending on ceiling or wall space.

Baseboard systems use heated water to warm a space through long, low-profile units installed along the base of walls. Baseboard heaters rely on natural convection, where heat rises from the unit and circulates throughout the room. They’re quiet, unobtrusive, and ideal for retrofits or spaces where ductwork isn't practical. In commercial settings, baseboard heating is often used in offices, hallways, or perimeter zones that benefit from supplemental or zoned heating, especially during colder months when consistent indoor conditions are important.

Chilled water systems use cold water circulated through coils or air handlers to provide cooling in large buildings. They’re a standard solution in commercial and institutional facilities like hospitals, schools, and government buildings. This approach offers high efficiency and central control, which makes it ideal for spaces with heavy cooling loads. When paired with air handlers or fan coils, chilled water systems can deliver consistent, large-scale cooling while reducing energy use and extending equipment life.

Hydronic heat pumps use electricity to move heat rather than generate it, providing both heating and cooling through water-based distribution. They extract heat from air, water, or the ground and transfer it into the hydronic system. In commercial buildings, heat pumps are an attractive option because they support energy efficiency goals and can be paired with renewable sources. Such systems are especially useful in facilities aiming to reduce carbon output while maintaining reliable, year-round climate control.