PEXATHERM Floor Central Heating

Transcription

1 PEXATHERM Floor Central Heating Installation and Operation Guide for Pipe-In-Board System Thank you for choosing Pexatherm floor central heating. We hope you will enjoy the benefits of comfort and energy savings for years to come. Complete and Easy to Install System Pexatherm warm water pipe-in-board central heating package is easy to install. A high degree of components prefabrication and attention to detail ensure fast and problem-free installations. The heating packages include all the components needed to put the system together and ready for connection to the heat source. All types of boilers or sources of warm or hot water can be used. It is ideally suited to condensing boilers for further saving in running costs. The Pexatherm pipe-in-board does not require any special tool to fix the heating pipe to the pipe fixing panels. Just push in place by hand or foot. Pexatherm basic components and floor x-section INSTALLATION The following points must be observed before starting installation. 1. Pexatherm pipe-in-board system is usually installed on solid concrete floor. 2. The floor must be clean, free from major surface irregularities and dry. 3. Depth of mm (this is dependent on the thickness of insulation supplied) from doorstep and other finished floor to base concrete is required where Pexatherm underfloor heating is installed. 4. All walls and steps must be in position. Plaster finish must be even and extend to 20 mm from sub-floor. 5. PEX plumbing pipes in conduit must be in place on the floor. They are hidden in the gouged insulation. 2 - Distribution Manifold The manifold cabinet is built into the wall at this stage if used (optional extra). The Pexapipe flow and return pipes from boiler to manifold are laid on floor and will be covered by the Pexatherm clipboard and insulation. If, however, copper pipe is used to supply the manifold their positions on the wall must be determined at this stage. The Pexatherm manifold is assembled and fixed to the walls or in the cabinet. The top section of the manifold is approximately half a metre from final floor level. See separate manifold instruction sheet. Electric cables from the boiler, programmer and room thermostats should also be in place, and terminate at a junction box or the Multizoner wiring centre near the manifold. Pexatherm Manifold on wall 1

2 3 - Insulation Material The edge insulation strip is unrolled around the perimeter of the room and adjacent to the wall. The strip can be tacked to the wall in a few places ensuring that enough material is allowed into the corners and across doors, and between floors of different levels. The Pexatherm multiboard serves a dual purpose. It is a combined floor insulation and pipe fixing panel and is placed directly on the floor, starting from a Overlapping the clipboard laid on insulation Hint: It is helpful to draw the pipe layout on the floor using large red and blue felt-tipped marker pens taped to either end of a one metre length stick. The flow for each room is drawn in red starting at the manifold and the blue marker is used when returning from the centre of the room. Pexatherm Clipboard on insulation. corner of an outside wall. Both overlaps of the first board are removed as well as one overlap of boards laid next to the wall. The boards are butted to the edge insulation already in place. The polythene flap of the edge insulation overlaps onto the boards to avoid seepage of screed between floor and wall insulation. Pexatherm clipboard can be easily cut with a sharp knife to fit the size of the room. Avoid gaps between panels and wall. Follow this simple procedure in every room until all the heated area is covered with insulation and clipboard. The same procedure of placing insulation if other insulation boards are used, such as foil backed polyurethane. Pexatherm tape is used between boards to form a vapour and screed barrier. The pipe lay-out, spacing, and length per zone is supplied with each project. The overall length of pipe is arrived at by multiplying pipe density (inverse of spacing) by area of room and adding to it twice the distance to the manifold. Further refinement can be achieved by having the pipes near patio windows spaced closer together, while pipe near internal walls are spaced further apart. The average pipe spacing for the room remains the same as specified on the drawing. Make sure that pipes will not cross each other anywhere on the floor and especially near the manifold. Mark the rooms or zones on the manifold using the provided stickers. The maximum pipe length per zone should not exceed 120 metres. A zone can cover more than one room. Corridors are usually heated from the pipes leading to other rooms. On the other hand, large rooms may require more than one zone per room. After drawing all the zones on the floor, measure the length of pipe required per zone by using a compact distance measuring wheel (available from us) and write the distance from the manifold on the floor in the middle and at the end of each zone. The pipe is marked at one metre intervals and the length should be checked regularly while being laid. Hint: If distance measuring wheel is not available, you can measure the length of zone by 'stepping it' and noting that each insulation panel is 1x1 m. Pipe laying starts at flow part of the manifold and clipboards are fixed every half metre except around corners where two or three clipboards are required. 4- PEX Heating Pipe The pipe is laid as shown in the supplied drawings, where the flow and return are always running next to each other, ensuring even floor temperature. The grid on the insulation provides an easy guide to pipe spacing. Hint: To avoid pipe getting entangled, your helper should uncoil the pipe by holding the coil on its edge unrolling only few metres ahead of the stapling. Sometimes the pipe must go through the walls to reach the manifold. Make sure that part of the pipe is wrapped with conduit and some insulation to avoid heat transfer into the wall. Caution: PEX pipe must not be bent to a radius of less than 120 mm. to avoid buckling and damage. If 2

3 accidentally buckled, pipe can be straightened by heating it gently with torch. The additive instruction can be found on a separate sheet and on the containers. Heating pipe is not installed under kitchen units, wardrobes, baths or toilet pans, unless specified. However, edge and floor insulation is laid in these areas to avoid heat migrating into the subfloor from the heated area. Pipes converging to manifold must be insulated to avoid overheating the area close to it. Conduit is place over alternate pipes and preferably the flow pipes, to reduce the heat output in this area. Wire mesh can be used to strengthen the screed in this area. 5 - Filling up and Pressure Testing. When all zones are installed and connected to the manifold, the system is filled with mains water using a hose. Fill one zone at a time to ensure rapid expulsion of air. Anti-freeze and inhibitors are added at this stage. Please follow manufacturers' instructions for the type and amount to be used with plastic pipe. Hint: Fernox Copal is used with aluminium boilers and CP3 and improved MB1 with cast iron ones. The system is then subjected to a pressure test (up to 10 bar) to check for any possibility of leaks in the pipe. It is normally kept at this pressure while the floor is screeded. The heating installer's job is complete once the Pressure Test Certificate has been signed and the screeding contractor has been advised of the points below. SCREEDING Screeding of the heated floor should be carried out as soon as possible by experienced crew observing the following points. 1. Minimum screed thickness over insulation is 75 mm. Reinforcing mesh laid over pipe is required if screed thickness is less than 65mm. 2. Quality cement is well mixed with sharp screeding sand in the ratio of 1:4. How to Use: A. Ready Mixed Screed litres of cement additive for each cubic metre of concrete/screed. B. Site Mixed Screed litres of additive for every 100 litres of water, or 4 litres per 44 gallon drum. C. Cement Bags litres of additive of every 50 kg. Of cement. 4. The screed should be well compacted around pipe either by using a temping plate or laid in two layers and hand compacted. 5. The screed should be allowed to cure slowly and should be coverd with poythene sheet if site is draughty and in warm weather. avoid walking on freshly laid screed for a period of 3 to 5 days. Cover floor with plyboard or even cardboard to reduce damage to surface during curing. Apply heat in stages of 5 o C and at least 21 days from l aying and even longer in cold weather. 6. Expansion joints must be used in large areas (over 40 m 2 )or in long corridors. The edge insulation strip acts as an expansion joint around the perimeters and in between two areas of the floor. 7. Wire mesh can be used in the floor in areas where there are high concentrations of pipe, for example, near the manifold or across a door way, or where the screed thicness is less than 50mm. The mesh should be placed on top of pipe and near the neutral axis of the screed layer to be effective. 8. For heavily loaded areas, reinforced screed is used, while concrete is laid over pipe on outside drives or in factories. The same procedures and precautions as above still apply. 3. Cement Additive Pexatherm cement additive can be used with concrete and screed mixtures. The addition of the additive will provide the right amount of liquid to the concrete/screed while keeping the water content to a minimum. It will therefore enhance the strength of the concrete/screed. The large synthetic content assures a tight bond within the concrete/screed, and provides excellent water repellent. Furthermore, the elasticity of the concrete/screed will be increased by approximately 30% which reduces the possibility of cracks developing. Pexatherm cement additive will plasticise the concrete/screed, and also allow it to completely envelop the heating pipes for improved heat transfer. The additive is not a retardant and therefore does not slow down the drying of the screed. FLOOR COVERING Most floor coverings can be used with Pexatherm, floor central heating. However, the response time varies from one type of covering to another. Floors covered with carpets transmit less heat and slower than those covered with tiles. Underlay should be avoided if possible. Only certain types of underlay with less than 0.15 K/Wm resistance should be used. Hardwood or parquet wooden flooring is laid on paper or expanded polyethlene sheet and allowed to expand in either direction. Floor surface temperature must not exceed 28ºC. Avoid using bitumen based adhesive for sticking PVC and wood floors. Use resin type instead in this case. Normal tile adhesive can be used otherwise. If in doubt consult manufacturers of adhesive. 3

4 The edge insulation is trimmed after floor covering is completed and just before skirting board is fixed to the wall. It is necessary for skirting boards and wall tiles to be fixed to the wall only to allow for floor movement with heat (and changes in humidity in case of wood floor cover). boiler. Pexatherm floor central heating requires a pressure head of at least 1 bar whenever possible to ensure that the pipes in the floor are free of air. Unvented sealed circuits using expansion vessel and filling loop with double check valve are best suited to the system and can be supplied by us. Further details on floor covering can besupplied if required by us in some cases and the respective material supplier. TEMPERATURE CONTROL 1 - Pexatherm systems are designed to the DIN and the new proposed CE standards. This means that the floor surface temperature must be controlled to 28ºC and therefore Manifold with 3-port Mixer. the water temperature in the floor is blended to a reduced temperature. A 3-port mixer is supplied and plumbed as shown in the separate sheet included with the dossier. Quickheat gas condensing boiler can supply water at low temperature when used for underfloor heating and hot water only. 2 - The Pexatherm Programmable Electronic Thermostat is wired according to wiring diagram in the thermostat instructions. It operates the two port motorised valve, boiler and circulating pump at the manifold. Separate rooms or zones can be controlled by zone actuators at the manifold using individual room thermostats (available separately). All the thermostats supplied have a night 'set-back' facility ensuring good response from the floor central heating. It is recommended that all electric wiring must be carried out by experienced electricians as a safety measure. Alternatiely the Multizoner I and II wiring centre can be used to wire all the components of the heating system without the need of motorized valves in some cases. 3 - The Pexatherm 3 or 4-port mixer (Minimix) with its servo-motor is supplied as part of the optional Delta weather compensated control system. This is wired directly to the Delta WG 100/200 enclosure. Further detailed instruction is provided for the Delta controller or the Multizoners from IPPEC. To operate the system at the optimum setting the following procedure is followed: 1. In the basic system, set the water temperature control valve situated on the return pipe near the manifold in mid position, and read the temperature gauge (also fitted to the return pipe). Wait until system temperature stabilises (approx. 35 o C). This may take some time. Alternatively open the 3 or 4-port mixer using the manual setting on the programmer/compensator with the Delta weather compensation system. 2. Now read the temperature difference between flow and return of each zone using a differential thermometer. The difference should be between 5-10 o C. in a stable mode. 3. Adjust the flow lock shield valve (located on the lower (flow) manifold, using an Allen key to maintain the same temperature difference between zones. Shorter length of pipe requires the lock shield valve to be closed a few turns more to balance pressure drop and flow rate compared with longer zone pipes. 4. The electric zone actuators replace the hand wheel at the top and hence the return section of the manifold where required. 5. Measure air and floor temperature in various rooms. The floor surface temperature should not exceed 30 o C. If it does, close the lock shield valve further for that zone or turn down the water temperature control valve to reduce the overall temperature at the manifold. Allow several hours for system commissioning as it takes time for the floor to reach required stable temperature. Better still, the heating should be run for several days and after all the floor finishs are in place before final commisioning. Manifold with 4-port mixer COMMISSIONING Once the screed has cured, boiler connected to the system, all the plumbing is checked for leaks, and the air is vented between boiler and manifold, the ball manifold valves are opened. Any air remaining in the system is expelled through the air vents at manifold or Fault finding and rectification Your Pexatherm floor central heating system consists of high quality components, is reliable and virtually 4

5 maintenance-free. However if you should experience any problems please follow the operation instructions. Cross Section of Concrete Floors that can be used with PEXATH ERM Pipe-in-Screed Underfloor Heating Plaster Skirting Board Edge Insulation 150 X 10mm CARPET TILES W O O D mm SCREED Floor Covering: 1- Carpet stuck or floated on heated screed. 2- Tiles stuck to floor. 3- Wood with T&G floated on floor with building paper in between. INSULATION mm CONCRETE 150+ mm Plaster or Polystyrene spacer C A R P E T Block & Beam C A R P E T SU SPEND ED C ON CRETE BEA M Example of primary connection of a mixed heating system of Pexatherm UFH on ground floor and Pexapipe radiator system on first floor 5