Clay Heating Panels – Thermal Heating System

1. OVERVIEW

Clayworks Clay Heating Panels are clay and wood fibre dry-lining boards with integrated heating pipes designed to carry hot or cool water through walls or ceilings. The panels thereby act as the heating or cooling element within a building.

They have a sandwich construction made of wood fibre and naturally dried clay plaster. The integrated heating pipes are identical to those used in underfloor heating and require no specialist plumbing.

Once installed, the system is invisible to the eye as it sits within the walls or ceilings. The application of Clayworks clay base coat and topcoat plaster completes the installation, creating a beautiful, seamless and healthy finish.

Once linked to a heat source, the panels warm up gently to radiate heat either downwards or across the room. The individual heating loops are linked to thermostats which allow the end user to control the temperature as they would do with conventional heating systems.

Clayworks Clay Heating panels are well suited for natural heat sources such as solar and ground source heat pumps. In warmer climates, running cold water through the pipes offers a gentle and healthy alternative to mechanical air conditioning.

The panels come in three sizes: 625mm wide x 1150mm long, 625mm wide x 950mm long and an end board 625mm wide x 550mm long. They are supplied with the heating pipes already fully integrated. Such an extremely high level of prefabrication allows for fast, cost effective installation. This saves working hours and drying times on the construction sites, leading to significant savings on time and material resources on site.

Clay panels are not suitable for areas where there is contact with running water.

2. HEALTHY INTERIORS

Due to the excellent breathability of both wood fibre and clay, our panels help minimise damp, aid thermal comfort and help protect the structural integrity of the building.

Infrared heat is used in medicine and is known to be gentle and effective.

Clayworks Clay Heating panels offer all of the health and sustainability benefits of clay when used as an internal building material:

• No VOCs
• No toxins
• No off-gassing
• Critically, clay helps to keep room humidity at between 40% and 70% the level at which the majority of adverse health effects are kept at bay including asthma. At these levels the likelihood for airborne infectious bacteria and virus to survive is the lowest.

3. COOLING SYSTEM

The panels are perfect as a cooling system: if cold water is sent through the water pipes, the system functions as gentle air conditioning without the noise, draftiness and high maintenance associated with traditional air conditioning systems.

4. HISTORIC BUILDING REFURBISHMENT

The panels are particularly valuable for historic building refurbishments due to their permeability. Clay plaster allows walls within buildings to breathe. The system also offers an alternative to underfloor heating where historic floors need to be preserved and areas of walls or ceilings are more suitable for integrated heating.

5. DESIGN FLEXIBILITY

Just like underfloor heating, integrated clay panel heating increases usable space as it removes the need for radiators. Especially when placed in ceilings, the system offers future design flexibility adding to the lifespan of the building.

A minimalist aesthetic is easily achieved.

Having the heating pipes integrated into dry lining boards also means that partitions can be built using the panels. This is an easy and efficient way to create partitions which not only include heating but also offer acoustic benefits. The weight of the clay is beneficial for cross-room noise reduction and the permeability of the panels buffers reverberation.

There are minimal design limitations due to the size of the individual boards or the pipes running through them because the heated boards are installed in combination with plain boards which can be cut to size. The only limit there is lies within the minimum size of a single heated board.

A range of specialist products are available for applications such as windows, external walls or areas of thermal bridging.

6. TARGETED HEATING

Wall heating in particular delivers targeted heat to specific areas where the effect of other heating systems can be lost due to drafts or challenging layouts. This is particularly valuable in open plan areas such as shopping centres, airports or office receptions. Heated walls behind reception desks directly benefit the wellbeing of staff and visitors whilst gentle heat in restaurants or spas behind built in seating can increase the overall level of comfort.

7. ENERGY SAVINGS

The way we feel warmth depends upon the total energy that reaches us – the more heat radiation, the less heat conduction is necessary. As a result, the room temperature can be reduced by 3 degrees while still giving the same feeling of warmth, enough to reduce heating costs by up to 18%.

In addition, the actual heat output of wall and ceiling heating tends to be far more effective than underfloor heating. The pipes run much closer to the surface and clay has superior heat conductivity to concrete or screed. There also is no need to wait for the heat to come through added layers such as timber flooring or tiles.

8. SUSTAINABILITY

• Energy-efficient: the panels store the warmth from the day and release it slowly in the night hours.

• High efficiency due to insulation against the wall which insulates against heat escaping into the wall or ceiling.

• Constructed primarily of natural materials – wood and clay.

• Clay works clay panels are highly sustainable due to the low energy required during production and the raw materials used. Clayworks clay boards can be 95% recycled.

9. DATA & PERFORMANCE

• Excellent sound insulation. Sound can be reduced by high mass material or soft wave reducing material.

• Basic thermal insulation: The core of the Clayworks Panel is 17mm wood fibre which provides good basic insulation.

• High inherent stability – excellent for stud constructions.

• Critically, clay helps to keep room humidity at between 40% and 70% the level at which the majority of adverse health effects are kept at bay including asthma. At these levels the likelihood for airborne infectious bacteria and virus to survive is the lowest.

• Absorbs and stores indoor air pollution.

• The clay’s capillary structure, its permeability and the number of micro cavities enables the material to absorb and store odours and smells and Ionise the air, contributing to a feeling of fresh air.

• Energy-efficient: the panels store the warmth from the day and release it slowly in the night hours.

• Constructed primarily of ecological materials – wood and straw.

• Clay works clay panels are highly sustainable due to the low energy required during production and the raw materials used. Clayworks clay boards can be 95% recycled.

• High efficiency due to warmth insulation towards the wall which insulates against heat escaping into the wall or ceiling.

• The clay plasters and panels absorb the warmth of the heating system and deliver it into the room by longwave, healthy warmth radiation.

• Fast temperature response – within 5-10 minutes – due to the low mass compared to full clay panels.

• Convenient panel sizes: Maximum size 625 x 1150m / 21 kg. Can be managed by a single person for wall mountings and 2 people for ceilings.

• The system includes end panels and connecting panels.

• Flexible modular system: Up to 8 panels can be connected in a row.

• Enough space for built-in sockets. Sockets with a diameter of up to 68mm can be drilled between the pipes.

• Marked pipe course.

• Savings on labour time and labour cost compared to underfloor heating systems due to less cost for the sub-construction.

• Only 40% of the room size is required for the heating panels: the remaining 60% will be unheated clay panels.

• Significantly less dust sweeping than air convection systems.

• In small spaces, no space for furniture or decoration is occupied.

10. THERMAL CONDUCTIVITY OF CLAYWORKS CLAY BOARDS

λges =0.073 W/(m · K); s(d)=0.031m

Based on panel buildup of 17mm wood fibre board within a 14mm clay sandwich.

Overall panel thickness is 31mm. (Excluding Clayworks clay base coat and topcoat plaster).

11. DIMENSIONS

• 625mm wide x 1150mm long x 31mm thick; weight 21.5kg; pipe length 6.5m.

• 625mm wide x 950mm long x 31mm thick; weight 17.5kg; pipe length 5.5m.

• 625mm wide x 550mm long x 31mm thick; weight 10.1kg; pipe length 3.4m (end board only).

12. INSTALLATION

• Fixed with staggered joints on OSB clad walls or timber/metal studs (w = 60mm) studs at 625mm centres. For masonry and stone we would recommend a soft wood subframe which allows for even spacing of screws to fix the boards. The subframe also creates a space to run services.

• Can also be fixed to a solid substrate i.e. masonry, concrete or stone using a mineral based adhesive.

• On ceilings or to the underside of rafters, fixed at 312mm centres.

• Fixing materials: drywall screws (4 x 45mm) or galvanised staples (length 50mm or longer, width 10mm or more, wire gauge 1.4mm or more).

• Fixing distance: approx. 150mm apart on all tapered edges. On ceilings or the underside of rafters, an additional row through the middle of the length of the board is required.

Installation overview

We strongly recommend that you contract with an approved installer. The following guidelines are for design and construction planning purposes.

Backing boards behind the panels

Wood fibre boards can be used for extra stability and added acoustic and thermal performance. The panels can be glued to any flat solid surface such as concrete walls and ceilings but for masonry we would recommend a soft wood subframe which allows for even spacing of screws to fix the boards. The subframe also creates a space to run services.

Installation instructions

1. Cut the clay board with a circular saw or hand saw.
2. Mount the board to the wall: the boards are either screwed, stapled or glued to the substrate.
3. Staple 100mm wide mesh over the joints to avoid cracks between the joints of the boards.
4. Wet the joints: it is easier to fill up the joints with clay plaster when the joints are wet.
5. Fill up the joints.
6. Apply Clayworks clay base coat (approximately 8mm) whilst integrating reinforcing mesh. Thickness of base coat depends on which fixing method is used and which topcoat plaster is selected.
7. Apply Clayworks clay topcoat plaster.

13. RANGE OF USE

Anywhere within a building except for areas where there is running water. The panels are especially suitable for bathrooms as the clay system absorbs humidity, however they cannot be used within shower enclosures or directly behind a sink as a splash back.

In a kitchen, clay plaster significantly decreases the build-up of grease, which tends to occur over time in all kitchens.

14. HEATING

Heating performance 80 W/m² (= ca. 48,0/57,6 W/panel) based on a flow temperature of 35°C and a room temperature of 20°C.

Heating circuit

Up to 8 panels or 60m pipe length. The feed pipe should be a 16 x 2mm pipe and therefore doesn’t have to be added to the total pipe length.

15. SOUND INSULATION DATA

Measurement of sound absorption in a reverberation chamber to EN ISO 354:2003.
Test object: Heating Panel end plate.
Test centre: Lucerne – Technology and Architecture for International Building.
Date of inspection: 20 March 2014.

Examination procedure
Expiry of the measurement: The necessary for the calculation of reverberation times are determined by the method with integrated impulse response (bursting of a balloon): The decay curves are determined by direct recording of the decaying sound pressure level with the netdb PRO 12 channel frequency analyser. For a valid measurement, the decay curve to min needs be -40 dB evaluable. The measurements are performed on 12 different microphone positions and 3 different sound source positions. The specified in each third reverberation time is the arithmetic mean of 36 measurements. reverberation times are determined with and without test specimen under the same climatic conditions.

Details
Surface of the test object: 10.7 m² air.
Temperature: 18.6°C.
Relative Humidity: 50% r. F.
Barometric pressure: 95807 Pa

16. CARE & MAINTENANCE

Should the panels incur damage, by being knocked by furniture for example, they can easily be repaired by taking out the damaged material and infilling with clay plaster.

17. SERVICES

Wiring within the panels is not possible but drilling through the panels for lights, sockets and so on is. We recommend running any services behind the panels and marking out locations of any fittings prior to applying the clay base coat and topcoat plaster. This simply makes it easier as the un-plastered heated panels have the pipe runs marked out on them so you know where to drill. You can drill anywhere apart from where the pipes run. It is not a problem to add further fittings after plastering as there are easy ways to trace the pipes such as spraying water and watching the clay dry first where the heating pipes run.

Fixings
The same way you would do for any plastered wall, you can put nails and screws in the wall, for heavier items such as built in floating cabinets etc. we recommend plywood backing but we can look at the project in detail and advise. See above re locating pipes – to not puncture them.

18. FIRE RATING

The panels are not yet fire rated. The clay plaster itself is BRE Class 1 fire rated (also fulfilling the requirements for Class 0 as outlined in the Building Regulations).