Model SRY-002-2 Solar PV Lighting Kit

The Model SRY-002-2 is a further enhanced version of the Model SRY-002-1 Solar Lighting Kits and consists of two LED lights, a mobile phone charger & a separate battery charging compartment where rechargeable batteries can be charged for use in separate portable radios or torches. 
The larger Solar PV Panel consists of a 9V/2.5W solar module with a 5M cable that provides flexibility in being able to suitably locate the Solar Panel to maximise the solar input during the daylight hours, and still have enough length in the cable to extend the light to a point where it can be best utilized.  The Solar PV module has a life cycle of approximately 10 years.  The inbuilt controller provides protection against over-charging and over-discharging and also includes short-circuit protection.    The battery pack consists of 5pieces of AA size x 1800mAH NI-MH (Nickel Metal Hydride) rechargeable batteries that are housed in a strong UV stabilized, heat resistant ABS plastic material for durability and longer life.   The LED Lamps that are supplied with the kit consists of 2 x 9V lamps with each having 18 Light Emitting Diodes (LED) together with a 4M cable.  A Mobile phone Charger connection in the battery pack allows direct mobile phone charging and several different types of plugs are supplied with the kit to cover most popular types of mobile phones.

In addition the Model SRY-002-2 has a separate compartment provided in the front of the ABS battery pack where two (2) 600mAH NI-MH rechargeable batteries, that are supplied with the kit can be charged during the daylight period as well.   These batteries can be used in a suitable flashlight or a portable radio.    After the solar PV module has been charged for between 6-8 hours there are three brightness setting options that can be used for the LED light.   The three settings will offer the following performance based upon both LED Lamps operating at the same time: Maximum Brightness for around 7 hours, Energy Saving mode for around 18 hours, and Low Brightness mode for approximately 45 hours of operation.   The Model SRY-002-2 instruction manual is available in English and French and dependent upon quantities other languages are available as well.   Each Kit weighs approximately 1.15 kilograms and is packed in a strong packaging box measuring 280mm x 210mm x 550mm.   Standard Packs comprise of 10 pieces per carton which measures 450mm x 310mm x 310mm and has a gross weight of 12.5 Kg.

By Mel Peatey

High Temperature Heat Pumps

High Temperature Heat Pump

The Metran High Temperature Air Source Heat Pumps transfer heat from the ambient air to water, providing high-temperature hot water up to 80°C. The unique high-temperature heat pump is widely used for house warming in the cooler climates as well as Commercial/Industrial applications, particularly in the tropical zones of the World.  With innovative & advanced direct heating technology, the heat pump can operate very well at ambient temperatures as low as 0℃ whilst still being able to generate high output temperatures of up to 80℃.  This ensures compatibility with normal sized radiator, based systems without the need for any supplementary energy source. Compared with traditional Diesel fuel or LPG boilers, the high-temperature heat pump can produce up to 50% less CO2 whilst saving up to 80% in operating costs.  The Metran High Temperature Heat Pumps are not only highly efficient, but are also easy and safe to operate.

Intelligent Digital Controller

The high temperature delivery from this new design of Air to Water Heat Pumps is achieved by using a combination of high efficiency American Copeland scroll compressors, environmentally safe R134a refrigerant, electrically activated expansion valves, larger evaporator design and specially designed high efficiency tube in shell heat exchangers.  A user friendly intelligent digital controller with blue LED back lighting is incorporated with the Heat Pump unit to easily adjust temperature setting to suit any application.  The electrical compartment is provided in a separate, isolated compartment to avoid internal corrosion and subsequently contributing to extending the operational life cycle of the Heat Pump unit.
In all cases each project design, followed by the correct High Temperature Heat Pump model selection is critical in order to maintain the required performance criteria and the durability of the system.  In addition, installation recommendations of clear, unobstructed minimum space clearances around the Heat Pump systems must be observed in order to maximize the performance and minimize the operating costs.  It is also advisable to mount the Heat Pump(s) on a solid concrete foundation and using shockproof bushes at the anchor points to maintain stability of the system, and reduce noise and vibration that may eventually contribute to damage of plumbing the connections. 

By Mel Peatey  

Model SRY-002-1 Lighting Kit

 The Model SRY-002-1 is a slightly enhanced version of the basic Model SRY-001E lighting Kit and consists of one LED light, a mobile phone charger & a separate battery charging compartment where rechargeable batteries can be charged for use in separate portable radios or torches.
The Solar PV Panel consists of a 9V/1.5W solar module with a 5M cable that provides flexibility in being able to suitably locate the Solar Panel to maximise the solar input during the daylight hours, and still have enough length in the cable to extend the light to a point where it can be best utilized.  The Solar PV module has a life cycle of approximately 10 years and is warranted for 5 years.  The inbuilt controller provides protection against over-charging and over-discharging and also includes short-circuit protection.    The battery pack consists of 5pieces of AA size x 1000mAH NI-MH (Nickel Metal Hydride) rechargeable batteries that are housed in a strong UV stabilized, heat resistant ABS plastic material for durability and longer life.   The LED Lamp that is supplied with the kit is a 1piece x 9V with 18 Light Emitting Diodes (LED) together with a 4M cable.  A Mobile phone Charger connection in the battery pack allows direct mobile phone charging and several different types of plugs are supplied with the kit to cover most popular types of mobile phones.

In addition the Model SRY-002-1 has a separate compartment provided in the front of the ABS battery pack where two (2) 600mAH NI-MH rechargeable batteries, that are supplied with the kit can be charged during the daylight period as well.   These batteries can be used in a flashlight or a portable radio.    After the solar PV module has been charged for between 6-8 hours there are three brightness setting options that can be used for the LED light.   The three settings will offer the following performance: maximum brightness around 6 hours, energy saving mode around 12 hours, and low brightness mode approximately 50 hours of operation.   The Model SRY-002-1 instruction manual is available in English and French and dependent upon quantities other languages are available as well.   Each Kit weighs approximately one kilogram and is packed in a strong packaging box measuring 245mm x 195mm x 510mm.   Standard Packs comprise of 10 pieces per carton which measures 410mm x 280mm x 255mm and has a gross weight of around11 Kg.

By Mel Peatey.

Multi-Function Heat Pumps

Multi-Function Heat Pump

The Multi-Function Heat Pump is a patented product with multi-usage functions.  They use a suitably sized Heat Pump module to deliver hot water, via an insulated storage tank as well as cooling (air conditioning), via a small buffer tank from one split type Heat Pump module.  
The use of energy efficient Japanese brand Mitsubishi, Panasonic, and Sanyo rotary or scroll compressors, depending upon the product capacity needed, as well as two (2) separate high efficiency plate heat exchangers, this combination significantly improves the energy efficiency to the point where the combined Coefficient of Performance (COP) for the heating and the cooling functions can be as high as seven (7) which represents an energy saving of 700% when compared to the electrical energy that would be consumed by separate electrical hot water system and air conditioners delivering the same volume of cool air and the same volume of hot water each day.  Whilst the electricity tariff supplied by the local utilities in any Region will still be the same the “effective” tariff would be 7 times less to deliver the same performance due to the efficiency of the combined Multi-Function Heat Pump Units.  For example if the actual tariff was the equivalent of US $0.12 cents per kWh then the “effective” tariff would be approximately US $0.02 cents per kWh.

Multi-Function Heat Pump - Operation Schematic

The built-in circulating pumps are the World renowned and reliable Wilo brand and they provides automatic water level control, and automatic water pressure controls.   The Multi-Function Heat Pumps also have inbuilt hot water flow and air flow controls, compressor exhaust temperature protection as well as automatic defrost and load adjusting controls.  By using the high efficiency rotary or scroll compressors as well as low noise fans, the actual overall noise levels remain low.  Side fan or vertical fan discharge units are available as options.  LCD or LED touch screen controllers simplify the various settings to suit each individual installation with cooling water temperatures as low as 7°C and hot water temperatures of up to 60°C.  The Metran Multi-Function Heat Pump units are capable of operating in all weather conditions and ambient temperatures of between -15°C and +45°C.

By Mel Peatey

Solar Thermal Panels and Heat Pumps Hybrid Systems

Figure 1

The addition of solar thermal panels in conjunction with Heat Pumps to form a hybrid system certainly does have the capability of creating a complete energy efficient solution for any hot water installation regardless of volume requirements.   Solar thermal panels will contribute their maximum free “solar” energy only during the daylight hours when the sun is shining brightly and without any cloud cover.   Air to water Heat Pumps on the other hand will continue to contribute free “solar generated” energy from the air during the daytime, rainy or cloudy periods, as well as night time.  Another point to consider is that air to water Heat Pumps will operate at optimum efficiency and therefore contribute the maximum level of free “solar generated” energy during the same periods of the day as the solar thermal panels which is, during the highest ambient temperature periods of each day.   Therefore when solar thermal panels are used in conjunction with Heat Pumps in a hybrid system the “actual” achievable saving in energy will be reduced because both systems enjoy a “positive” COP.  When the Solar thermal panels are contributing the maximum amount of free “solar” energy, the Heat Pumps will also be contributing the maximum amount of free “solar generated” energy from the air.

Figure 1: above shows a typical layout with solar thermal panels connected with Heat pumps. The daily energy contributed by solar thermal panels can be calculated by using the following formula:

kW = Collector area x Collector efficiency x Average Daily Radiation (Mj/m²) ÷ 3.6

Figure 2

In addition, solar thermal panels actually lose efficiency as the water temperature rises as shown in the chart - Figure 2.  For a good quality solar thermal panel operating in the highest instantaneous solar radiation conditions it can be seen that the efficiency at a point where the temperature difference between the solar panel and the ambient temperature is around 30 degrees Celsius the efficiency is approximately 75%.  If we select as an example the average daily radiation of 17.56 Mj/m² per day for Manila Philippines the equation would be:

 kW      = 1m² x 0.75 x 17.56 Mj/m² ÷ 3.6

            = 3.66 kW/m² per day of available solar collector aperture area.

Therefore, during the maximum energy collection period for the solar thermal panels they will contribute approximately 3.66 kW of energy for every one square metre of collector aperture area that is installed.  In the same location (Manila - Philippines) during the same period & same climatic conditions that has been used to assess the solar thermal panels, the Heat Pumps would also be operating efficiently and producing a COP of approximately 3.8 to 4. 
Then assuming that the solar collector panels were NOT installed as part of the hybrid system and only the Heat Pumps were required to contribute the total energy requirement during that same period.  The 3.66 kW/m² per day of “free” energy contributed by the solar thermal panels would only require approximately 0.96 kW of energy to be “consumed” by the Heat Pump to produce 3.66 kW of output using a COP of 3.8 for the Heat Pumps.  However, in the location of Manila – Philippines during the peak high ambient temperature periods the COP for the Heat Pumps may even be around 4 of higher which would result in even less energy to be “consumed” in order to produce 3.66 kW of heating output.  Therefore, the lower calculated energy consumption, for the Heat Pumps that would be required to produce the same heating output as the solar thermal panels becomes the “actual” or real amount of energy saving that should be used to calculate the ROI or payback in relation to the cost of supplying and installing the solar thermal panels in a hybrid system with Heat Pumps.

By: Mel Peatey.

Metran Swimming Pool Heat Pumps

The Air to Water Metran Swimming Pool Heat Pumps are available in both vertical and horizontal air discharge options.   Depending upon the installation location there are also options for the outer casings of the Swimming Pool Heat Pumps namely; powder coated steel, UV stabilized ABS or stainless steel.   The main feature or “heart” of the Metran Swimming Pool Heat Pump is the patented titanium heat exchanger.  Without an effective and durable heat exchanger a swimming pool heat pump will become ineffective in a very short period of time due to the rapid deterioration of incompatible components.  For example; the advantage of the titanium heat exchanger over a cuprous nickel alloy heat exchanger is that it is not susceptible to the highly corrosive chemicals (particularly high levels of chlorine) that are generally present in all swimming pools and spas.  The external casing component of the titanium heat exchanger is a fully molded non-corrosive, high impact strength material that can withstand high water pressures as well to ensure durability and maximum performance of the complete Metran Swimming Pool Heat Pump at all times.

Scroll compressors are used because they have 50% fewer moving parts than standard piston type compressors. This equates to greatly improved reliability and improved efficiency as well as reducing noise levels to a minimum.   The Digitally-based microprocessor can control water temperature to within 1ºC of the set point.  The controller also permits the user to pre-set different pool and spa water temperatures and it can also prevent unauthorized tampering by the use of locking controls via a Celsius control key.  The versatility of the Metran Swimming Pool Heat Pump is again demonstrated by its capability to heat and cool a swimming pool or spa in different climatic conditions.  This allows the operator to have full control all year round.   The Metran Swimming Pool Heat Pump can warm your pool or spa with the reliability and efficiency of our other heat pumps, but with the flip of a switch, it can also cool your pool or spa to refreshing temperatures during hot summer months. For cooler climates, heating & cooling heat pumps offer unique advantages over the passive defrost models.

The Metran Swimming Pool Heat Pumps are also hot gas defrost heat pumps that are uniquely equipped for an active defrost cycle.   Active defrost involves directing hot refrigerant vapor to the heat collector thereby melting accumulated ice away in a matter of a few minutes and then allowing the heat pump to return back to normal heating cycle.  Standard defrost heat pumps may remain off for extended periods when defrosting during very cold weather.  However, because of the hot gas defrost function on the Metran Swimming Pool Heat Pump it has the ability to continue to operate-even during freezing weather.  Hot gas defrost models will extend the swimming season longer than any standard-defrost heat pump.  A large variety of Models are available ranging from 4 kW heating output right through to 149 kW heating output which will ensure a suitably sized product can be selected from the calculation chart for any project.

By Mel Peatey

Solar Lantern Lighting Kit

The Solar Powered Lantern is a lighting system that consists of 28pieces including an LED lamp, battery and controller all placed in a strong metallic housing and ABS plastic as well as a solar panel and a AC/DC adapter.  The battery is charged by two methods:
1.    By electricity generated through the solar panel
2.    By the AC/DC Adapter that is supplied with the kit.
The lantern is basically a portable lighting device suitable for either indoor or outdoor lighting covering a full range of 360 degrees.
The product features adjustable lighting modes where the setting can be “strong” to an “energy saving” setting   The “energy saving” setting has a brightness of approximately half the maximum brightness strength but this setting will allow the lights to operate for a longer period during the night time.
In addition, there is a DC output for mobile phone charging, which is suitable for any type mobile phone. The complete unit is compact and light weight, as well as being easy and convenient to use.

The product is suitable for outdoor campers, hunters, hikers, boat cabin lighting, vehicle roadside emergency lighting, recreational vehicle cabin lighting, earthquakes and hurricane emergency kits.  Indoor applications include home lighting in rural regions where the power supply is irregular or scarce and also in urban areas as backup lighting during power cuts as well as for mobile phone charging during these periods.

By Mel Peatey

Solar Home Power Supply System Model No.: SHS1206

This great new addition to the range of solar lighting kits now allows you to create a power solution to match your requirements.  Each system includes the solar panel, charge controller, solar battery, DC to AC inverter, cables & DC 12V lamps to complete your system.
The Model SHS1206 - 6W Solar lighting Kit gives you all the components needed to install a small lighting system in remote homes, caravans or wherever you need a reliable power source for lighting.

This Solar Lighting System consists of 3 LED lights & mobile phone charger as shown in the illustration.  The PV Solar panel has a maximum generating capacity of 6W and has an expected life cycle of approximately 10 years.   The three lights that are supplied with the Model SHS1206 consist of 2 pieces of 12V/3W LED bulbs and 1 x 12V/1W LED bulb.  The controller incorporates over-charging (14V) and over-discharging (10.5V) protection functions as well as short-circuits protection.  The battery is a 12V-4AH lead-acid battery with a rated charging current of 1Amp and a rated discharging current of 2Amps.

There is a no load loss of 8mA and a USB port current of 500mA.   The estimated full charging time with the solar panel is ten hours when clear sunny conditions are available.   Orientation of the 6V Solar PV panel in a direction facing towards the equator (North for Southern Hemisphere Countries and South for Northern Hemisphere Countries) will ensure maximum collection of solar energy each day.
An approximate lighting duration after the battery is fully charged of around 5 hours when the 3 lights are operated at the same time can be expected.

By Mel Peatey

Low Cost Solar Lighting Kits

In remote Regions of Developing Countries the people tend to use the traditional methods of either burning firewood, lighting candles or kerosene lanterns in order to provide lighting during the night time periods.  It is well known that candles and kerosene are expensive for these people as well as being harmful to the eyes - particularly when children are exposed to these types of lighting.   In addition, gathering firewood is heavy, hard work that is generally carried out by the women and sometimes the children of these communities and burning firewood can contribute to larger rural fires that can destroy large areas of vegetation.  Burning firewood is also not really environmentally responsible and could be considered to be somewhat of an unsustainable resource.  In many cases the remote Regions in Asia, Pacific Islands, and Africa are blessed with abundant amounts of solar energy which is freely available but is very much underutilized.  In order to overcome the problems with traditional lighting methods there has been a concerted effort to develop low cost, but effective solar lighting systems for these Regions.   The benefits of using the low cost solar lighting kits is that they are easy to install, are safe to handle, and simple to operate.  The solar PV lighting kits generate direct (DC) current which is totally safe to use unlike alternating current (AC) that is used in most developed world locations.   A NI-MH (Nickel Metal Hydride) rechargeable battery is used instead of lead-acid battery or NI-CD battery because of its long life, no memory effect, non-toxic, and is environmentally friendly.  Once the kit is installed, the sun will provide the energy needed to operate one 6V/1W LED lamp that is supplied with the Model SRY-001E (as illustrated above) for up to 8 hours after the battery is fully charged.   The expected life cycle of the Model SRY-001E lighting kit is approximately 10 years.  Over charging and discharging protection devices are incorporated into these lighting kits to simplify the use of the products.  Additional charging points are also available for other devices such as mobile phones.
 
Since the year 2009 over 100,000 pieces of the Model SRY-001E Lighting Kits have been installed in various parts of Africa and another 20,000 units have been sent to remote locations in South America.  The World Bank has recently conducted quality testing for the Model SRY-001E product and it has now been passed and has been accepted for their "Lighting Africa" Solar program.
There are a number of different Solar lighting kit models available in the range that are CE accredited and also include extra LED lamps and other charging options.  These kits have slightly larger solar panels that are capable of collecting the additional solar energy that is necessary to power the extra lights or charging points. 
 
By Mel Peatey

Solar Thermal Collectors Connected to Heat Pumps

There can be some advantages gained by connecting Solar Thermal Collectors to Heat Pump water heaters, but there are some important points to assess before this combination can be recommended.  The first point to consider is the economics of the project.   In other words will the addition of Solar Thermal Panels provide sufficient reduction in traditional energy use, which can then be calculated as a cost reduction when compared to the actual initial cost of supplying and fitting the Solar Thermal Collector Panels?

                                                              Schematic Image Only

There is an unwritten expectation for energy efficient products such as Solar Thermal and Heat Pump systems to provide a reasonable “payback” period, and this can sometimes be linked to the expected life cycle of the system or probably more closely linked to the warranty period offered for the products involved.   If the capital cost can be recovered within the warranty period then it is worth being given further consideration. However, when assessing the value of adding Solar Thermal Collector Panels to a Heat Pump installation it must also be remembered that during the daylight hours when the Solar Thermal Collector Panels could be contributing to the energy input of the system, that is also the period of each day that the Heat Pump units would be operating at their highest efficiency as well so the amount of purchased (input) energy for the Heat Pump units during the day time period could be between 3½ to 4.0 times less than the actual output that is produced in the form of hot water depending upon geographical location, ambient temperature and humidity.

The thermal contribution to a Heat Pump system from Solar Thermal Collector Panels is governed by the amount of radiation that is available at any given time and this can be intermittent because of varying weather conditions.   Therefore it is important to recognize that the Heat Pump units must be considered as the primary heat source and sized accordingly to be able to meet the total hot water requirement of the project due to the reliability of Heat Pumps being able to produce energy efficient hot water in all conditions including daytime, night time, as well as cloudy or rainy periods.  The Solar Thermal collectors will therefore only provide supplementary energy input during periods when there is a favorable level of radiation available for collection.  A number of factors can influence the decision to add Solar Thermal Collectors to a Heat Pump installation or not, but generally it has been found that in Regions where Government or Utility incentives are offered for the inclusion of Solar Thermal Collector Panels and the value of that incentive covers the cost of the Solar Thermal Collector Panels then obviously the economic equation is positive however, when no incentives or subsidies are available then there are some questions that need to be asked as to the added value of the Solar Thermal Collector Panels fitted to Heat Pump Units.

By Mel Peatey

Water to Water Heat Pumps

Another option for Commercial/Industrial Heat Pump water heaters is the Water to Water - or hydro sourced Heat Pump.   Water source heat pumps (WSHP) are specialized types of heat pumps that can also be used as reverse cycle or multi function units that use water as a heat source when in the heating mode and as a heat sink in the cooling mode. In the Water to Water HeatPump, heat is absorbed or rejected in a fluid medium rather than from the ambient air. Water loop heat pumps (WLHP) use a circulating water loop which could be from a chiller/cooling tower system as the primary heat source for the liquid refrigerant causing it to vaporize before moving it to where it is upgraded by an electrically-driven compressor and is then subsequently delivered at a useful super heated temperature for heating potable water via a suitable heat exchanger.

A typical schematic of a multi function Water sourced Heat Pump shown above indicates how in some cases a single Water to Water Heat Pump Unit can be used to provide hot water, air conditioning, as well as under floor heating if required.   In the schematic layout above the primary heat source can be provided by any medium (ground, lake, sea water or hotel cooling tower circuits) where heat energy can be captured (transferred) in the primary evaporator in the Heat Pump Unit.   These types of Heat Pumps can also be used very effectively for just the hot water output function depending upon the project requirements and still have the capability of delivering a very high Coefficient of Performance (COP) outcome of over 370% more than the actual energy consumed.   However, when used as a multi function unit for example, delivering hot water and air conditioning in an ambient temperature environment of around 24ºC the combined COP’s for both functions can be as high as 700% more than the energy consumed for the operation of the system.

By Mel Peatey.

Difference between Heat Pumps and Diesel or Gas Fired Boilers

In years gone by heating sources for large volume Commercial/Industrial Water Heaters have mainly been in the form of diesel or gas fired boilers.   These systems have always been afflicted with some disadvantages such as heating inefficiencies and the rising cost and the vulnerability of supply in some cases for these fuel types.  In addition there has also been a need to duplicate these systems with stand-by units to ensure continuous operation in the event of a breakdown or maintenance requirements.   The heating inefficiencies are caused – because only a low percentage of the gross energy that is produced from “burning” the diesel or gas, is actually transferred to the water or other fluid that is being heated.   This percentage of energy input can be between around 75% for new systems down to as low as under 50% for older systems.  The main cause of energy inefficiency in diesel or gas fired systems is that a good proportion of the heat that is generated through the burning process of these fuel sources is dissipated into the atmosphere through the flue pipe or chimney.   Further inefficiencies (up to an additional 30% reduction) can be experienced if the diesel or gas fired systems (in a Hotel for example) are required to heat the water to steam (100ºC) and then that steam is directed to a calorifer type storage tank to produce potable water at 60ºC for circulation to the various fixture points.    
In most cases when a diesel or gas fired boiler is initially installed it has to be duplicated with at least one additional identical system as a stand-by unit that will be able to handle the full hot water load requirement when the primary system requires repair or maintenance.   During these repair or maintenance periods the complete diesel or gas fired system is totally shut down and cannot contribute in any way to the heating requirements of the project; therefore the need for a stand-by unit.   However, the larger Commercial/Industrial Heat Pump products that are now available are normally fitted with multiple Heat Pump modules in the one unit that are digitally controlled in such a way that they can operate individually or together at any given time.   Provided the Heat Pump daily run cycle design is done correctly for each project there is usually no requirement to include any stand-by units thereby contributing positively to the reduction in capital cost and subsequently having a positive effect on the ROI equation.   The design of the system is critical in order to maximize the daily run cycle and at the same time keeping the daily run cycle at a suitable operational percentage that will allow the system to still contribute effectively even if one of the Heat Pump modules is isolated for service or maintenance at any time.  The non requirement of stand-by units for the Heat Pump alternative also reduces the amount of occupied floor space required in the building to house the heating systems.
Finally, a Heat Pump solution also provides a positive effect on the operating cost due to the energy efficiency of its design.   Whilst diesel or gas fired boilers produce a negative Coefficient of Performance (COP) because of the various heat losses that are experienced during their operation, a Heat Pump will actually produce a positive COP that provides a heating output in the form of hot water of somewhere between 360% to 400% more than the energy that is actually consumed by the system depending upon regional ambient and humidity weather conditions.   Heat Pumps are also capable of operating effectively in most areas of the World during the daytime, night time, or rainy and cloudy periods.  
By
Mel Peatey

Heat Pumps compared to Solar Water Heaters

An Air to Water Heat Pump provides an ideal energy efficient hot water system alternative for both domestic household use, or for larger Commercial applications.  In reality a Heat Pump provides slightly less energy savings when compared to a domestic solar water heater, but there are a number of other significant advantages associated with the use of an Air to Water Heat Pumps.

One major advantage of the Heat Pump is the aesthetic appearance that is gained by not needing any thermal solar panels and in some cases a storage tank on the roof of the building to ensure efficient operation.  In some cases roof structures may have to be reinforced when they are required to support the weight of a domestic sized solar storage tank that can weigh in excess of 400 kg.  In addition, the installation cost of an Air to Water Heat Pump is very simple compared to the installation cost of a solar water heater, and this significantly lower installation cost for the Heat Pumps should also be taken into consideration when assessing the overall installed cost of either product alternative.

Another advantage of the Air to Water Heat Pump is the low energy input from the electricity supply that is required to operate the system, while at the same time producing an output of around 3 times more than the actual electrical input, when operated in average ambient temperatures of 20 degrees Celsius.  This results in an energy saving (reduction) of approximately 75% when compared to traditional electric water heaters.  In Regions where the average ambient temperature is higher than 20 degrees Celsius the actual energy savings can be higher due to the extra heat energy that is available from the ambient air in these locations.  Air to Water Heat Pumps do not require direct sunlight to operate efficiently because they collect free energy from the ambient air.    Contrary to popular belief, a solar water heater does requires back-up electrical energy to operate the booster element during periods of inclement weather, low radiation periods, and at night time when there is a need to supply hot water during those times.  When comparing similar volumes of hot water delivery the annual booster or back-up energy needed to ensure solar thermal water heaters provide a continuous supply of hot water during all weather conditions, or if hot water is needed during the evening period, is similar to what is expended annually for a Heat Pump to drive the evaporator fan and compressor.   A domestic sized Heat Pump could, in some cases, operate from Photovoltaic (PV) solar cell system due to the low energy input needed when compared to the actual output that is delivered in the form of hot water.  This makes the Heat Pump products ideal for isolated and heavily forested locations such as remote Eco Resorts.

By Mel Peatey.

Benefits of using Integrated Heat Pumps for Small Commercial Installations

Integrated Heat Pumps that are designed with a storage tank and heat pump module in one unit can definitely be an economically viable option to provide hot water for small commercial installations such as single block multiple level hotels with up to 100 accommodation rooms or in some cases even up to 150 rooms.    Provided there is sufficient floor space to locate the Heat Pumps and the proposed design (number of units) is correct the integrated models can provide a complete solution of hot water storage capacity as well as multiple heat pump modules that allow flexibility to maintain total hot water load requirements to be maintained even during periods when some units could be undergoing servicing or maintenance.
 
For example if a quantity of integrated systems were designed with sufficient units to meet all of the hot water demand criteria for a particular project and based on a 70% daily run cycle it would mean that the total heating capability of the combined units would be 30% above what is actually required on a daily basis.   Therefore the equivalent number of integrated heat pumps that represents 30% of the total could be isolated for a period of time while servicing or maintenance was carried out and the rest of the integrated heat pump units could still meet all of the daily hot water requirements for the project.   This design also removes the requirement to install additional stand-by units therefore reducing the capital costs and subsequently improving the return on investment (ROI) for the installation.
 
The plumbing pipe work connection design for multiple integrated heat pump installations is simple and straight forward with the main considerations being the use of reverse return pipe work which basically means that the first integrated heat pump unit that the cold water supply pipeline is connected to should be the last unit that the hot water delivery is taken from.   In addition the geometry as well as the length of branch connections off the main header pipe line to each integrated heat pump unit should remain the same in order to provide a balanced cold water flow and hot water delivery and ensure that each integrated heat pump unit contributes equally to the overall hot water requirement.  
 
By  Mel Peatey

Viable Alternative Energy Reduction Methods

There is no doubt that one of the biggest challenges facing the World today is the task of reducing our dependence on fossil fuels, and reducing harmful emissions into the Earth’s atmosphere.   Most Governments look towards heavily subsidising Photovoltaic (PV) Solar Panels as a way of achieving this goal however there are other ways that possibly could be considered as a priority over PV Solar in order to achieve higher energy reductions for less cost.  The use of energy efficient Heat Pump heating and cooling products, particularly for larger commercial or industrial installations can produce substantial energy savings at a much lower cost but with a similar saving in energy that is achieved with Solar PV Panels.   The current disadvantage with Solar PV is the overall efficiency of the panels (generally between 17% and 18%) to collect available Solar energy when the sunlight is available.   On a good clear day this still only represents approximately 33% of each 24 hour period and that is an additional drawback associated with Solar PV Panels.
 
In small installations, for a similar capital investment, energy efficient Heat Pump heating and cooling products can more than double the actual energy reduction achieved when compared to Solar PV Panels.   For larger installations such as Hotels, Hospitals, Processing Factories, and other similar places the reduction in energy can be even higher if energy efficient Heat Pump heating and cooling products are used.  The purpose of giving strong consideration to the Heat Pump method is that they will create a much larger reduction in energy load requirements from the main generating facility which can be achieved quickly, easily and at a much lower cost.   Because Heat Pump heating and cooling products substantially reduce the energy load from the generating facility they therefore achieve the first stage of being energy independent by reducing the need to augment existing, or build new generating facilities to service the needs of the ever expanding population.
 
If Governments were to consider providing the same level of subsidy that is available for Solar PV Panels and use that to subsidise large Heat Pump heating and cooling products then they could quite easily achieve a much higher Return on Investment (ROI) for any funds invested.   Solar PV Panels can still be used as an energy reduction alternative, but in the early stages of working towards this goal it may be more beneficial to give a higher priority to energy efficient products such as Heat Pumps that can provide an immediate and high impact to energy reduction for the same level of investment, but with a significantly improved ROI.
By
Mel Peatey.

Typical Air to Water Heat Pump Cycle

The heat pump operates on the basis of a working fluid (refrigerant/coolant) which changes state (liquid/gas) in a continuous cycle and absorbs and releases heat.

The heat pump cycle is essentially based on the Carnot cycle. (Theoretical thermodynamic cycle proposed by French Physicist & Engineer Nicolas Léonard Sadi Carnot in 1824)

Heat pump heating/cooling circuit is shown below:

 

The diagram illustrates the operation of the heat pump cycle:

The Importance of Heat Pump Design

To achieve the best economical benefits from the installation of Heat Pump water heaters, the design is critical.   For domestic installations there is a little more flexibility because daily hot water volume requirements are considerably lower than those required in commercial or industrial applications, and therefore a more general approach can be made to selecting the most suitable domestic system.  However for the larger and more continuous daily volume requirements for commercial or industrial applications, a suitably designed Heat Pump water heater is critical in order to achieve the most economically suitable outcome.  The most important issue with the larger volume installations is firstly that the designed system must be able to – do the job that is expected of it and that is, to provide hot water at the fixture point at any time of the day and on any day of the year.  

Heat Pump Performance Comparison

The “Metran” Heat Pump operates with the use of electricity.   The electricity is used only, to drive the compressor, and fan in the “Heat Pump” section of the system.   The metran Heat Pump systems electrical draw is approximately 3 to 4 times less than the heating output capability therefore providing a saving in energy costs of between 75% and 80% when compared to a traditional electric water heater. 

Heat Pumps - How they work

A Heat Pump transforms heat from a low temperature level into heat at a high temperature level at which it can be used for heating purposes. Even in wintertime with temperatures far below 0°C a Heat Pump can take energy from the environment.This is performed by an endless “cooling” cycle. The cooling liquid evaporates at a very low temperature and takes a substantial amount of energy from the ambient air, when changing from a liquid to a gas phase.

Welcome to the METRAN GROUP

Air to Water Heat Pump Specialists

Metran International Pty. Ltd. offers a complete design service for Heat Pump installations in all types of new and existing Commercial/Industrial applications, as well as being able to offer the most cost effective Heat Pump Units to suit each application. 


Each design presentation includes the calculated daily hot water requirement, any peak load requirement, as well as a calculation for Return on Investment (ROI) on each installation.


A full range of domestic as well as Commercial/Industrial Metran Heat Pump Units are available for the International Markets of Asia, Pacific Islands, India, and Middle East.