Heat Pump Pack 3 Install Guide (LWDV 91 – 1/3 + H(D)V 9-1/3)
|Heat Pump Pack 3 LWDV 91 - 1/3 + H(D)V 9-1/3 Return Buffer|
|Heat Pump Pack 3 LWDV 91 - 1/3 + H(D)V 9-1/3 Return Buffer|
This is a brief guide to help with the planning, installation and pre-commissioning of the Omnie Heat Pump Pack 3 incorporating the alpha innotec LWDV 91 – 1/3 + H(D)V 9-1/3 heat pump. Detailed information is available in the Operating Manuals provided by AIT Deutschland who manufacture the heat pumps. The Operating Manual contains most of the installation information such as dimensions, performance data and electrical loads. Read this along with the Omnie Installation Guide we also provide.
The LWD range consist of an outdoor thermal unit (LWD) and an indoor hydraulic unit (HMD). The LWD has the finned heat exchanger/fan unit, compressor, water heat exchanger and controls in a weather proof case. The LWDV is the latest in the range with an inverter driven compressor which provides modulated heat output.
The indoor H(D)V unit includes the circulating pump, pressurised system safety set, 12ltr expansion vessel, main control PCB and the User Interface encased in an expanded polypropylene box. 3 electrical supplies are connected to the HMD from the consumer unit to power the control circuit, the compressor and the electric back-up heater. The compressor supply and the control supply are “piggy-backed” to outdoor LWDV unit along with a third cable carrying data between the two units . See the HMD Operating Manual for full installation data.
The Omnie air source heat pump packs always include a buffer tank to ensure effective defrosting and efficient operation.
A 60ltr wall mounted tank is supplied with the pack. Make sure there is space in the house for this along with the HMD unit.
Locating the buffer tank under the HMD unit is popular with our regular installers. The buffer tank connections are on the bottom with a 1/2″ tapping on the top for a vent valve. The buffer is also an excellent air separator.
Always consider carefully the location of all the components to comply with all regulations and with the manufactures instructions in the Operating Manuals. Ask yourself if there is enough space around the units for future maintenance and air flow. Check with the Operating Manuals for the minimum space required.
Good air flow through the outdoor unit is vital to the operation, the clue is in the name “Air Source”. Do not restrict the air movement through the unit in any way and be aware that the exhaust air could be as much as 10 degrees lower than the surrounding air so make sure it can dissipate and not lurk around the house or garden.
Snow and leaves can block the fins on the heat pump so consider this when choosing the location. It is best to keep it out of direct sunshine as they can get very hot in summer which will deteriorate the casing over time. West facing means that it will be subject to driving rain and wind which is not good. East and North are preferable in the UK as these are the driest least windy sides of a house. Remember when you need the heating most there wont be any benefit from placing it on the south side.
Floor or Wall Brackets
Choose whether your LWD unit is to fix to a wall or sit on a concrete base. Either option is supplied in the pack, alternative mountings are not an option. If the supplied brackets are modified or not used it may affect the performance and the warranty could be invalid.
During normal operation the outdoor unit collects moisture from the air, this is captured by an internal drip tray in the bottom of the unit which is fitted with a drain. The drain should be allowed to run away either to a building drain or to an underground soak-away. This condensate water comes from the air and is therefore inert and can be discharged into a normal soak-away or surface drain. It is important to keep the drain short and at a steep angle, it should also be lagged to prevent freezing.
Note the pipe sizes on the schematic because they may be larger than you would expect. This is vital for a reliable efficient system, smaller pipes will lead to problems.
The installation of a heat pump is notifiable work under the Building Regulations. The regulations are in place to ensure that important works are carried out to a minimum acceptable standard. Exceeding the standards will improve efficiency performance and reduce running costs. Always check with the local Building Control Department at your local authority before starting work. If the work is not registered it can cause problems when it comes to selling your property in the future or could invalidate insurance in the event of an indecent.
The LWDV 91 1/3 is MSC certified so is the heart of an MCS certified installation. In order to obtain the MCS certificate the end user must have a contract with an MCS registered installation contractor. This must be in place before any work starts on the project. The MCS certification process cannot be carried out retrospectively unlike other certificates in the constructions world . Visit the MCS web site for further information.
In order to register for the RHI it is necessary to have an MCS certificate for the complete heating system. Check with the OFGEM guides to find out if your circumstances qualify for RHI registration.
An up to date EPC is also required for the RHI registration.
Planning permission normally requires a minimum energy rating for a property. The efficiency and low carbon emissions from a heat pump will help with achieving a good EPC rating which will help with getting planning permission on a new build. Also note that by designing for an efficient heating system the RHI payments may be greater.
Download the Install Guide PDF here
|Setting out and Installing the Outdoor Unit|
Make sure you have all the components on the hydraulic schematic. Take note of the items that are excluded from the pack like pipework and lagging, isolating valves etc.
Wall Duct Kit
The Wall Duct Kit is an optional item that is a neat solution for wall penetrations. The kit consists of a 1000mm long 110mm diameter plastic duct with rigid foam insulation segments, 2 No. 28mm copper tubes fitted with a flat face 1″ BSP coupling on one end that connects to the 2 No. flexible hoses that connect to the heat exchanger in the outdoor unit.
Provision is made in the duct for the condensate drain and the cables.
Included in the kit is a sturdy moulded cover that is screwed to the underside of the heat pump covering the pipe and cable entry, the wall duct and the condensate drain. A moulded cover is included to cover the pipes at the rear between the unit and the wall.
The wall duct kit includes the flexible hoses so if this is not being used they need to be included separately.
Flexible hoses are supplied if the Wall Duct kit is not selected. The hoses connect to the heat exchanger in the outdoor LWD unit with 1″ swivel nut flanges with fibre gaskets that are supplied in the ancillary box. They are needed to prevent both vibration being transmitted into the pipework but also to prevent stress on the heat exchanger connections.
Positioning the Outdoor Unit; Floor Feet or Wall brackets
The pack will include either feet for mounting on a concrete slab or brackets for fixing to a wall. Whichever way you are mounting the unit it sits on 4 No. rubber bobbins that are supplied in the ancillary box. Note: – DO NOT REMOVE ANY OF THE CASING UNTIL THE UNIT IS IN POSITION and you are ready to connect the pipes and cables.
The hydraulic connections to the heat exchanger in the outdoor unit are accessed by removing the lid and the left hand end panel. A Torx bit is provided in the accessories box to help with this. Try not to lose the screws.
A foam rubber closing plate is included, this is slipped around the two hydraulic hoses when they are in position then slid down until it sits in a recess in the base closing it off to dirt noise and most importantly animal infestation. The cables are passed through the holes provided.
|Mounting the H(D)V Indoor Unit|
The Hydraulic Module must be mounted in a weatherproof location with normal moisture levels, it contains sensitive electronics. An outhouse or garage is suitable but it must be frost free in winter.
The H(D)V is wall mounted so make sure you have a suitable wall available which will support the weight and allow access to the hydraulic and electrical connections. Note that the cables enter the right side of the casing with cable glands and sufficient space is needed to allow access to the wiring terminations.
It is feasable to mount the H(D)V above the WPS60 buffer tank
When removing the H(D)V from the packaging find the ancillary box and put it somewhere safe. Under the H(D)V unit you will find the mounting template; a cardboard rectangle with the drilling positions for the mounting holes. Place this on the wall where the H(D)V is to be mounted and drill the holes.
The fixings supplied with the unit in the ancillary box are suitable for brick, block or concrete walls. Plugs, nuts and washers are included. If mounting on a stud wall it will be necessary to make suitable arrangements beforehand
Ancillary Box Contents
Before mounting the unit on the wall remove the Safety Assembly from the box and using suitable thread sealant screw into the boss on the top left. Ensure the gauge is facing the front of the module.
|Heat Pump Pack 3 Hydraulic Installation|
Follow the guide below paying attention to the size of the pipes. The sizes given are assuming you are using copper pipe but any material suitable for domestic heating systems is suitable. Note though that plastic pipe fittings restrict the flow more than copper because they fit inside the tube where copper fits on the outside. Also MLC and HDPE pipe have a greater wall thickness so 32mm is equal to 28mm copper. Remember a small change in pipe diameter has a large effect on the pressure loss.
Do not deviate from the logic of the schematic, connect the components in the order they are shown here. Download a PDF of the complete guide that you can take to site either printed on paper or on a mobile device.
Keep the outdoor unit as close to the indoor plant area. It is good practice to have the hydraulic module and the two cylinders close together to keep the pipework compact and the wiring short. This will have a large effect on the cost of installation. It is also much easier to trace problems in the future.
A long pipe run from the outdoor unit will also have a detrimental effect on the performance. If you need to place it more than 10m away from the house use 40mm HDPE in Pre Insulated pipe such as Microflex. Bury it below ground 700mm as the temperature down there is more stable than the air, it cant be damaged either.
Download Pack 3 Installation Guide PDF here
3 Way Diverter Valve
The diverter valve has a fast action with a 45deg turning angle. The common connection is marked AB, the heating circuit is marked B and the DHW circuit is marked A. The schematic shows it fitted in the return line but it can be mounted in the flow if it is easier on site. This does not affect the operation.
Do not fit the valve with the motor under the valve. This will cause problems, if it cant be fitted on the top of the valve it can be mounted sideways.
Omnie supply a Filterball strainer with the pack. this is sufficient on a new system with underfloor heating. it is essentially a ball valve with a 0.7mm mesh gauze strainer in the ball. when in the off position the gauze basket can be removed and cleaned without the need for other isolating valves.
If adding the heat pump to an existing system the previously had a boiler fitted add a good quality magnetic filter after power flushing the pipework etc. The gauze strainer with 0.6-0.8mm mesh is still needed.
Beware; most Y type strainers are not suitable because the mesh is too small.
The by-pass valve is supplied with the heat pump pack. It must be fitted as shown on the Hydraulic Schematic between the flow from the hydraulic module and the return from the heating circuit up stream of the buffer. The by-pass valve must be adjusted to achieve the minimum flow through the heat pump when the heating circuit is shut down while keeping enough pressure to ensure full flow through the heating circuit when it is fully open. This is normally between .2 and .3 on the scale. It is not preset, every system is different.
A clean hydraulic system is essential for efficiency and reliability. A chemical clean of the system is necessary before putting into service to remove mill scale, installation debris and bacteria, all of which will clog the system and stop it working. Do not leave the system full of mains water after cleaning, corrosion is most active early on. Immediately after cleaning fill the system with the thermal fluid and purge the air. it will protect against corrosion.
Bacteria affects modern low temperature heating systems because it is not sterilised by the temperature as it was in the past. Bacteria will produce slime that grows while corroding the metal components in the system and will block plastic underfloor heating pipes. Residual dirt and soldering flux is nutrient to bacteria, it will also block the narrow passages of the heat exchanger thereby increasing the running costs while reducing comfort.
The heating fluid is circulated through external pipes and the outdoor heat exchanger. In order to protect the components from freezing in the event of a power cut during exceptionally cold weather Omnie recommend and supply premixed de mineralised water/glycol solution. Not only does this protect the system from freezing to -13degC it also protects against scale, corrosion and bacteria. Mono propylene glycol is mixed with de-mineralised water and supplied in 20ltr drums. The mixture also contains biocide and inhibitors to protect against infection and corrosion. Under normal circumstances the solution should be good for the life of the system. The fluid must be added to a clean system.
It is vital to balance the flow throughout the system. This must be done at the pre-commissioning stage and should include: –
The heat pump requires three separate power supplies;
These are connected to the indoor Hydraulic Module. Pass the cables through the rubber glands on the side of the box and clamp to the chassis. Strip back enough wire to reach the terminals. The compressor is connected to X8 terminal block and the heater to X9 which are located in the electrical box inside the H(D)V.
If the HMD is to be installed remote to the consumer unit it can be helpful to use a 3 way auxiliary consumer unit close to the HMD with an isolator and 3 MCBs which can be supplied with a single cable from the main incomer.
In addition to the power supplies it is very useful to incorporate a Cat6 Ethernet cable between the HMD and the location of the broadband router. The controller is connected to the house broadband router by Ethernet cable, then after changing a few settings in the controller it communicates with a remote server. Operating logs are stored on the secure server which can then be accessed either via a web page or by the AlphaApp. See more detail about the remote monitoring here.
The outdoor Heat Pump LWD unit is in turn connected to the Hydraulic Module (H(D)V) by fitting the plugs supplied to the cables from the unit.
The outdoor LWDV 91 unit is supplied with 3 pre-wired flex cables. When the unit is in place on the mounting brackets remove the lid by removing the self tapping screws around the edge. The cables are coiled up inside the compressor compartment.
The 2.5mm flex powers the compressor, the 1.5mm flex powers the controls and the screened cable carries data.
It is good practice to fit an isolator switch within sight of the outdoor unit. Use an IP67 isolator and mount it at least 1m above the ground. Only isolate the compressor and control supplies, this can be done with a single 4 pole isolator. If you need to extend the cables refer to BS7671 for the correct conductor size and protection. This is the responsibility of the qualified installing electrician as only they know the conditions the cables are subject to.
The data cable can be extended with SY cable 3core – 0.5mm. As data cable it is screened from interference by the braid so it is important to connect the braid of the existing cable to the braid on the extension cable. Connect the braid in the plug to terminal 3 which is earthed to the chassis in the socket.
The diverter valve motor is connected directly to circuit board terminal strip X3. The cable has 3 wires; permanent live (Brown) and neutral (Blue) and a switched live (Black). Connect the brown and blue wires to terminal block X10 and the black wire to Out 7 on X3.
Secondary Circulation Pump
if a secondary circulation pump is used it can be wired into X3 – Out 2 and neutral from X10. The controller has a programmable timer inbuilt with multiple daily time periods to suit the customers live style.
Return Temperature Sensor
The return Temperature Sensor is pre-wired into the H(D)V unit. It will be tucked behind the electrical box on a 6m long flex. Coil up any surplus and tuck it back in the Module. Strap the sensor to the common return pipe making sure it is against a metal pipe with the thermal paste supplied with the module. The sensor must be lagged before starting the heat pump.
The DHW sensor is supplied loose with the pack and must be inserted into the pocket at the middle of the cylinder. The sensor is wired into terminal X5 – NTC3 and GND3. Keep the sensor cables separate to power cables as they can pick up interference and lose accuracy.
|Omnie Pack 3 Installation Guide|
Read the text carefully and refer to the Operating Manuals for the outdoor LWD 70A/SX and the indoor HMD1.
Download Pack 2 Installation Guide PDF CLICK HERE
Download the LWD primary Operating Manual PDF CLICK HERE
Also download the Supplementary Operating Manual PDF CLICK HERE
Download the controller manuals.
Luxtronic Operating Manual Part 1 for End Users and Installers CLICK HERE
Luxtronic Operating Manual Part 2 for Installers CLICK HERE
When all the system components are mounted and the pipework connected the system must be prepared for commissioning in accordance with the Domestic Building Services Compliance Guide. This will include pressure testing, chemical cleaning and flushing to remove debris then filling with the correct thermal fluid.
alpha innotec recommend filling the system with demineralised water, the Omnie standard is to fill the system with pre-mixed antifreeze solution based on demineralised water. This will protect the system down to a minimum temperature of -10degC and also protect against corrosion and scale build up. Scale is the heating demon which will destroy efficiency and eventually the expensive system components.
It is very important that the system is not filled with tap water after cleaning without inhibitor. ideally fill immediately with premixed antifreeze solution then purge the system of air. Oxygen will cause corrosion by consuming inhibitors leaving the system vulnerable.