Installation Methods for Air-Source Heat Pump Floor Heating

There are two methods for installing air-source underfloor heating systems: dry-lay and wet-lay.

Dry-Lay Method

The dry-lay method was developed to address the challenges of traditional wet-lay installation, such as high construction difficulty, lengthy project timelines, and maintenance issues after installation. In dry-lay installation, water pipes are no longer secured with a concrete gravel bed; instead, specially designed plastic templates are used to hold the pipes in place by snapping them into the templates’ raised edges, making installation very convenient. The flooring is laid directly on top of the plastic templates. Hot water transfers heat through the air and the templates to the floor, which then heats the surrounding air.

By embedding the pipes directly into specialized installation molds—eliminating the need for a fill layer—this method offers simple installation and rapid heat dissipation. The installation height is typically 30–35 mm, though the cost is relatively high.

Wet Installation Method

The wet installation method is currently the most mature installation technique for hydronic underfloor heating systems. It is relatively inexpensive and dominates the domestic underfloor heating market. The term “wet” refers to embedding the heating pipes within a concrete layer, followed by the installation of flooring materials such as tiles on top of the concrete. This concrete layer not only protects and secures the pipes but also serves as the primary medium for heat transfer. The concrete layer ensures even heat distribution, minimizing the risk of localized overheating or underheating.

After laying the pipes, the space is filled with concrete. The installation depth is typically 70–80 mm, providing excellent heat retention and low construction costs.