AN INTRODUCTION TO HYDRONIC UNDERFLOOR HEATING - a concise guide for architects & specifierson planning underfloor heating systems

Oct 25, 2026

Uploaded by asba

A concise guide for architects and specifiers on incorporating hydronic underfloor heating into building design. The text explains how warm water is pumped through floor-embedded pipes, how heat is distributed via manifolds and pipe loops, and why radiant, evenly spread comfort is achieved with discreet installation. It compares underfloor heating methods, outlines installation suitability for new builds and retrofits, discusses heating sources, control considerations, and highlights energy efficiency and running cost factors.

LanguageEnglish

CategoryTechnology

FormatPDF

Pages20

Reading Time50 min

AccessFree to download

Introduction

Underfloor heating: the ultimate in comfort & design

Heating profile and comfort benefits

Energy efficiency and heat sources

How does underfloor heating work?

Can underfloor heating be installed in my home?

New build vs retro-fit suitability

Underfloor Heating Methods

In-slab (Kiwi UF)

Variotherm

European screed underfloor heating

Metal plate timber floor system

Can underfloor heating be used with radiators on the same system?

AN INTRODUCTION TO HYDRONIC UNDERFLOOR HEATING a concise guide for architects & specifierson planning underfloor heating systems Introduction This guide is intended as a basic guide to the fundamentals of hydronic underfloor heating to assist specifiers to incorporate underfloor heating in their design. (Hydronic underfloor heating works by pumping warm water through pipes set inside the floor.) Please contact us for more detailed information. Contents Underfloor heating: the ultimate in comfort & design 3 Underfloor Heating Methods 5 Can underfloor heating be used with radiators on the same system? 6 What can I use to heat the system? 7 Can I heat my house from solaror a wetback system? 8 Can I only heat part of my house or install a system incrementally? 9 What are the running costs like for an underfloor heating system? 10 What level of control is there in a hydronic underfloor heating system? 11 Design & installation issues to consider when planning underfloor heating 12 Design & installation process for underfloor heating systems 18 Our Expertise 19 Underfloor heating: the ultimate in comfort & design Luxurious, silent & discrete Underfloor heating is widely regarded as the most luxurious form of heating. Its radiant heat is evenly distributed throughout the room; wall to wall, floor to ceiling. Its heating profile means rooms are warmer at floor than ceiling level ensures not only warm feet and a clear unstuffy head, but warmth and comfort. Hard floor surfaces are warm to the touch – a key feature with increased numbers of new houses being built with concrete floor surfaces. What’s more the system is totally hidden from view and takes up no wall space – very important to many people, especially where large glazed areas mean there is little or no wall space. Water can hold nearly 1,000 times are much heat as the same volume of air so large amounts of heat can be moved around the house through comparatively small pipes without the need for large ducts and the noise of blown air. Energy efficient Hydronic underfloor heating is much more efficient and with much lower running costs than electric underfloor. The heat can be provided by specially designed air to water or ground source heat pumps, or by boilers fuelled by gas, diesel or wood. How does underfloor heating work? The heat source: A boiler or heat pump supplies heat to the system by heating the water that is pumped through it. Primary pipework carries the heat from the heat source to the manifold(s) . Manifolds distribute the heat to the underfloor pipe loops. Pipe loops, with hot water flowing through them, heat the floor, typically at least 1 loop for every 20m2 of heated floor area. Controller switches the heat source on and off, and directs the heat to where it is needed to heat the rooms to the desired temperature. Can underfloor heating be installed in my home? | Heating Method | New Build? | Retro-fit to existing home? | | --- | --- | --- | | In-slab (Kiwi UF) | 3 | 7 | | European screed | 3 | 3 | | Multitubo Micro-screed | 3 | 3 | | Alloy plate system for timber joist floors | 3 | 3 | When underfloor is retrofitted the floor level will be raised which means door heights etc will be reduced, unless spreader plates are used under a timber floor. Underfloor Heating Methods |

1 | | | | | | --- | --- | --- | --- | --- | | | | | | | |

| | | | | 1. In-slab,‘Kiwi’, underfloor heating Heating the construction slab is the most commonly used form of central heating in New Zealand. Pipes are laid on polystyrene insulation or attached to reinforcing mesh. Advantages: Relatively inexpensive and simple to install. Large thermal mass retains heat. Disadvantages: High thermal mass means slow response to controls. Because the outside edges of the slab are not insulated there can be heat lost to the footings and re-bar, and to the environment.. 3. Variotherm Variotherm is a qu

FAQs

How does hydronic underfloor heating work?

A boiler or heat pump heats water that is pumped through pipes embedded in the floor. The primary pipework carries heat to manifolds, which distribute it to underfloor pipe loops that warm the floor to the desired temperature.

What are the main benefits of underfloor heating compared with other comfort heating?

The radiant heat is distributed evenly across the room, producing warmer floors with a clear, unstuffy head. The system is quiet and discrete, hidden from view and taking up little or no wall space.

What heating methods are discussed, and how do they differ?

The guide covers in-slab (Kiwi UF), Variotherm, European screed underfloor heating, and a metal plate timber floor system. Differences include pipe spacing, thermal mass, system thickness, suitability for retrofit, response speed to controls, and relative installation cost or labor requirements.

Oct 25, 2026

Uploaded by asba