When people think of modern heating and cooling systems with heat pumps, the first thing that usually comes to mind is underfloor heating. It makes sense: in Europe, it’s the standard, and as we saw in a previous article, it's the perfect match for a heat pump because it operates at low temperatures. But a complete HVAC system is rarely built using just one type of radiator. That's where the fan coils — a type of heating system that offers features not provided by underfloor heating and is increasingly becoming a standard component in high-end residential projects in Chile.
When looking for high-efficiency heating for a new building, heat pumps top the list. But to maximize a heat pump's performance, it's essential to pair it with a low-temperature heat emitter. Fan coils meet that exact condition: they operate with water between 35 °C and 45 °C—the same range in which a heat pump achieves its best COP—and still deliver high heating capacity thanks to the forced circulation of air through the heat exchanger.
In new homes, heat pumps are increasingly being combined with underfloor heating as the primary system and with fan coils as a supplement. The reason is simple: Underfloor heating and fan coils serve different purposes. Underfloor heating maintains a stable temperature across the entire surface of the room through radiation—the most natural form of comfort there is—but it is a system with high thermal inertia: It takes hours to raise the temperature from 15 °C to 22 °C. The fan coil, on the other hand, has low thermal mass and responds within minutes.
Practical synergy: underfloor heating as the primary climate control system, always running at a moderate temperature; fan coils as an on-demand boost when you need to heat a room quickly. An everyday example—in the morning, a few extra degrees in the bathroom can make all the difference. And while 18 °C is ideal for sleeping, 22 °C is better for concentrating at a desk. The fan coil unit allows for these transitions without forcing the entire house to the same temperature.
The other compelling argument—perhaps the most relevant one for the Chilean market—is that a fan coil unit combined with a reversible heat pump (such as the R290 or R32 series from EnergySave) works also as a cooling system in the summer. Instead of circulating hot water through the heat exchanger, the system circulates cold water (typically between 7 °C and 12 °C), and the fan delivers conditioned air into the room.
This means that A single installation covers the entire year: the same hydraulic circuit, the same outdoor unit, the same emitter. There is no longer any need to install separate split-system air conditioners, with all the construction work that entails: additional drilling, separate refrigerant piping, multiple outdoor units, and the usual aesthetic consequences.
With summers getting hotter and hotter—a trend evident both in Santiago and in parts of the south-central region that historically did not require air conditioning—this reversible capacity is shifting from being a nice-to-have feature to a basic requirement in new projects.
One issue historically associated with fan coils was noise—loud motors, audible fans, and disturbances in bedrooms. The current generation has solved that problem. The Silence Thin by Emmeti, which is part of the Scanditec ecosystem, uses technology from modulating ventilation which continuously adjusts the fan speed to match the actual heating and cooling demand, keeping noise levels to a minimum in both heating and cooling modes.
In practice, this makes it possible to install fan coils even in bedrooms and spaces where people spend long periods of time without compromising acoustic comfort—something that, until a few years ago, required specifying different units depending on their location in the home.
Another major advancement is design. Modern fan coils are designed to blend in architecturally, not to hide it. The Silence Thin, for example, has a slim profile that allows it to be installed as part of the furniture or wall paneling, without the bulky housing typical of traditional fan coils.
The version THIN-4-V includes a built-in thermostat with a front-panel touchscreen (control SMART TOUCH) that allows you to adjust the room temperature without relying on the central control system. For multi-zone projects, this means you can customize the temperature in each room without having to wire an additional thermostat to the wall.
The fan coil is a component, not a standalone system. Its performance depends on how it is integrated with the rest of the hydronic system:
This integration is what sets a well-specified installation apart from one cobbled together from separate parts. When the entire ecosystem is specified, each component contributes what it does best, and the system’s overall efficiency reaches its theoretical maximum.
Not every project requires fan coils. A small project can be handled with just underfloor heating and a heat pump. Fan coils make sense when:
If you're sizing a HVAC system for a residential project, a hotel, an office building, or any application where the balance between heating, cooling, and zone control is important, let's discuss how to integrate fan coils into the design.
