What Is an In-Floor Convector and How It Works

An in-floor convector (also called a trench heater) is a heating unit recessed fully into the floor and covered by a decorative grille set flush with the finished surface. It connects to the same hot-water heating system as a radiator, but unlike a wall-mounted radiator, it's almost invisible: only a narrow grille shows at floor level. Below we explain how it's built, how it heats a room, and where it's used.

How an in-floor convector works

It works by convection: the movement of air. A heat exchanger carrying hot water sits inside the trench. Cool air near the floor sinks toward the exchanger, warms up, rises, and the process repeats, creating a gentle circulation of warm air through the room. Placed along floor-to-ceiling glazing, the convector lifts a warm stream straight up the glass and blocks the cold, preventing condensation and drafts at the window.

What it is made of

• Casing (trench body): recessed into a floor niche or set into the screed.
• Heat exchanger: copper-and-aluminum, where copper conducts heat quickly and the aluminum fins release it into the air.
• Decorative grille: the only part visible from above, chosen by color and material to match the floor.
• Fan (24 V): forces air through the heat exchanger; fitted only on forced-convection models.

Natural and forced convection

There are two types of in-floor convectors:

• Natural convection: air moves on its own, driven by the temperature difference. Completely silent and needs no electricity.
• Forced convection (24 V fan): a built-in fan pushes more air through, so the unit delivers more output for the same installed length and heats up faster.

For guidance on which type to choose, see our separate article: convector with or without a fan.

Where they are used

In-floor convectors go where heating has to stay invisible and there's no room for a radiator under the window:

• floor-to-ceiling windows and full-height glazing;
• glass facades, conservatories, bay windows;
• minimalist interiors with no wall-mounted heaters.

How it differs from a radiator

In short: a radiator heats partly by radiation from its hot surface and has high thermal inertia, while a convector works by moving air and heats up faster. For a full comparison of the two, see the article in-floor convector vs radiator.

In short

An in-floor convector is a hot-water heating unit hidden in the floor. It heats by convection, which makes it ideal for large windows, and it comes with or without a fan. Every Novaterm model carries a 5-year warranty, and we deliver across Georgia.

If you want to know whether a convector suits your space, contact us and we'll give you a free consultation.