The first design and energy efficient radiators in the market. Low-H2O stands for Low- water content and mass. Low-H2O radiators contain only 10% of the water content from a panel radiator with identical output. Hereby the inertia is minimal so these radiators can react immediately on external factors, allowing you to benefit from free heat sources such as sunshine, cooking, ironing etc. Low-H2O also stands for Low- water temperatures: these radiators are actually designed to operate on a supply water temperature starting from 110°F (with optional DBE even from 90°F).

Since they only have to heat up 10% of the mass of a traditional panel radiator, the reaction time is much faster. The high tech finned tube element transfers the heat immediately into the room. Also this element stops much faster than any alternative. Each second that your radiator is emitting heat after you switch off the system, is a waste of energy. A traditional panel radiator or radiant floor heating continues emitting heat for a long time, due to it’s Low- mass and water content Low-H2O responds immediately. An independent test of the BRE* (*British Research Establishment) has proved this.

The Low-H2O range offers models that fit into any interior. In comparison with a panel radiator, Low-H2O radiators work on the principle of convection. With traditional panel radiators it usually gets too hot in front of the radiator and too cold in the back of the room where there is no radiator. With Low-H2O radiators this problem is solved due to its better air circulation at lower air temperature.

Due to the quick reaction time, Low-H2O can react immediately to all changes in the room. When external heat comes into the room the radiator stops immediately, preventing an overshoot of the room temperature for optimal benefit from these free energy sources. When the temperature in the room tends to drop, the Low-H2O reacts directly, maintaining every square inch of the room at a comfortable temperature.

Jaga Low-H2O elements are designed to work with Low- water temperatures. The corrugated fins are developed with a maximum aluminium surface and large contact area with the copper tube. The fin distance is optimised to generate the best airflow through the element when using low water temperatures. Up to 16 parallel/serial tubes with specially designed collectors, allows lower water flow while reducing the pressure drop and maintaining the required turbulence. The element is based on the principle of a cross flow heat exchanger, whereby the temperature difference between the water and air is always optimal. The short contact distance between the fin and the air reduces the outlet air temperature, this maintains a laminar airflow in the element and reduces stratification in the room. This means that the warm air does not go immediately to the ceiling but mixes with the ambient room air, just where you want it to become warmer.

In general, you have to double the dimensions of the radiator when reducing the supply water temperature from 170°F to 130°F (this is approximately the point where condensing boilers become fully efficient). Doubling the Low-H2O radiators has a minimal effect on the total mass and inertia. With traditional systems, the water content and mass of the radiators becomes very high. More mass costs more energy to heat the system and increases the inertia of the system.

When reducing the water temperature, the effect of doubling the radiator dimensions is immediately clear: traditional radiators become even much slower!! Slower reacting systems consume far more energy and cannot benefit from free energy.

Modern panel radiators are already equipped with convector fins to increase the output. These radiators have fins that cover the complete length of the frontpanel. These fins are always much larger than the highest Low-H20 element, thus the contact distance between the fins and air is much longer. Hereby the air gets much warmer.
This has several disadvantages:
• the air gets dry and dust particles in the air become carbonised,
• the higher the exit air temperature, the higher the stratification. This means that the warm air goes immediately to the ceiling, where you don’t need it.
• with increasing air temperatures the air speed will increase also. The air moves between two convector fins, faster air movement causes turbulent airflow. This actually limits the output of the radiator.
In general you have to double the dimensions of the radiator when reducing the supply water temperature from 170°F to 130°F (this is approximately the point where condensing boilers become full efficiency). When doubling the volume of a panel radiator, the water content goes from two gallons to four gallons per radiator. For an installation with 10 radiators this goes from 20 up to 40 gallons. With a Low-H2O installation it goes from a quarter gallon to half a gallon. For the same installation with 10 elements this goes from 2.5 gallons up to 5 gallons. That’s 35 gallons less to heat up which results in a much faster reaction a higher comfort level and even more energy savings!

There are several reasons why Low-H2O is so much better, not only for your wallet, also for the environment:
• Since Low-H2O elements are designed to work on Low- water temperatures they allow your condensing boiler to work always in condensing mode. Heatpumps and solar panels can be installed with Low-H2O radiators without a problem.
• Due to the Low- mass, Low-H20 elements have an extreme fast reaction time. There is no heat storage in the radiator they heat up and cool down much faster. This allows you to benefit maximally from free energy sources (such as sunshine) and to heat up the room only when necessary. It’s no use to keep your temperature at 70°F while you are a sleep or at work, this affects your money and our environment.
• The ratio between energy storage and output for a Low-H2O element is approximately 0.04 . For a panel radiator with identical output this is approximately 0.40. This means that it takes +/- 10 times longer before a panel radiator stops with emitting heat. In the old days this was not a problem since the insulation of the houses was so poor that we needed heating 24hours a day. With modern houses the insulation is so good that we can reduce energy consumption with a fast reacting system on Low- water temperatures.

In a study performed by Building Research Establishment, a British independent research laboratory, a house with Low-H2O elements annually emitted as much as 220 lbs less CO2 than a traditional system. Low-H2O is therefore much less polluting for the environment. If all homes were fitted with Low-H2O the Kyoto standard would immediately much more achievable. (*BRE report available at Jaga upon request). Low-H2O elements save on your energy bills (*source: Building Research Establishment), this also benefits the environment since fossil fuels are saved. All Low-H2O units are made of fully recyclable materials such as copper, aluminium and steel, FSC wood in Jaga’s attempt to have a fully cradle-to-cradle product. The mass of Low-H2O systems is approximately 10% of the mass with traditional panel radiators. This means that 90% of the raw materials are saved. Did you know that for every pound of material, approximately 8 pounds of waist is produced? Therefore Low- mass systems such as Low-H2O help us to save the planet. Every Low-H2O product has a LCA (Life cycle analysis) this indicates the effect of every product on the environment. All Jaga Low-H2O elements have a 30 year guarantee. Sustainability is not only saving energy today but means also creating products that last for a very long time.

Low-H2O elements have a positive effect on your boiler on two different ways:
• The lower the water temperature, the more efficient your boiler becomes. Since Low-H2O elements are designed to work with Low- water temperatures, you can operate the condensing boiler always in condensing mode.
• Modern boilers have very compact heat exchangers which are vulnerable for stress caused by the temperature difference between supply and return water temperatures. Due to the fast reaction time, the return water reaches the operational temperature much faster. Therefore the difference between supply and return water temperature reduces very fast, preventing stress on the heat exchanger in the boiler.

The answer is no. Your boiler capacity is determined by the heat loss calculation of your building. Although Low-H2O elements use less water and are smaller in size, they still provide the same amount of heat as conventional radiators. When the boiler also provides the domestic hot water, you have to dimension the boiler according to this. Never over dimension a boiler to much: because modern boilers modulate their capacity. A higher capacity means a higher output at the minimal modulation. The lower the output at minimal modulation, the more efficient the boiler capacity can be controlled.

The finned tube element is very compact so the contact between the fins and the air is very short. This limits the exit air temperature and prevents the air from drying out.

Not like panel radiators Low-H2O heating is based on convection. This means that the cabinet doesn’t get hot to start emitting heat. Jaga Low-H2O cabinets are safe to touch at all times, even with water temperatures of 190°F. There are even special cabinets with soft rounded corners and completely concealed pipe connections. That’s why Low-H2O heating solutions are the first and safest choice for nurseries, schools, homes for elder people, health authorities, government departments, leisure centres and public buildings.

Radiant floor heating is a high mass system and therefore the inertia is very high. It’s not easy to set back the room temperature during the night and while you’re at work not even to mention to benefit from free energy such as sunshine through the windows. Every minute that you heat your house at night or while you’re not home, is a minute of energy wasted. Therefore it’s ideal to combine radiant floor heating with a fast reacting system such as Low-H20. This allows you to set the radiant floor system at 64 °F for basic comfort. The Low-H2O can be installed to get the room at the desired temperature of 68°F – 70°F, allowing you to set back the temperature at night or while you are away from home. When the sunshine comes into the room, the thermostat will close the water flow to the Low-H2O element. Since there is close to no heat stored in the element, it will stop emitting heat immediately, preventing a temperature overshoot without opening a window. The Low-H2O elements can work on the same water temperatures as radiant floor heating!

Scientific research has showed that the best position for a heating appliance is in front of the places with the highest energy losses. Therefore the heating appliance should be installed in front of the windows, especially when you have windows that cover the complete façade. Radiators in front of these big windows are not only blocking the view but they also increase the energy losses since radiation goes directly through the glass. The thermographic pictures clearly indicate that radiators in front of the windows are heating up the glass, emitting heat to outside. Jaga has developed special Low-H2O window solutions that can be integrated into the floor (Mini Canal) or on the floor (Mini or Knockonwood freestanding). These units are not only architectural pleasing, they also turn the cold draft from the window into a curtain of warm air to compensate the heat losses. Since these units are based on convection, there is no radiation directly through outside so all the produced warmth is maximal used. The infrared pictures indicate clearly that the Low-H2O units are not visible with a termographical camera.

Unlike traditional baseboard heaters or convectors, Low-H2O elements are designed to work without any noise. Since most models have multiple pipes with the inlet and return connections on the same side the expansion of the tubes is better controlled. The fins are equipped with a special expansion collar to reduce eventual noise. Even with outside temperatures of -22°F and a supply water temperature of 190°F, these elements operate without any noise.

Any installer should be capable of installing a Low-H2O element, the installation is similar to any radiator installation. All units are delivered with a complete installation manual in English. If you are not comfortable with the installation, please contact our local representative (see website, sales network) or contact the Jaga headquarters (

All our radiators are delivered with a standard ½ inch NPT connector. When using a thermostatic valve the connection can be made with a compression fitting (sleeve coupling). The diameter of the pipe work you have will be determined by your system. Please consult a Plummer for advice and guidance. For more information you can contact our local representative (see website, sales network).

These solutions are the future techniques in the world of heating technologies, providing supply water at temperatures of general 130°F. Since Jaga Low-H2O elements are designed to work with these water temperatures, they offer a perfect combination with these modern techniques.

Jaga Low-H2O elements have a 30 year guarantee on the fin tube element and 10 years on the cabinet. The first Jaga radiators were produced in 1962, many of these radiators are still operational today. When you are refurbishing your house, it’s easy to remove the cabinet for painting the walls.

This is a calculation based upon a number of variables. Room size, height, and type of insulation are the main factors that determine the output requirement. Also the model, dimensions and type of unit determine the output. For an accurate calculation, a heat loss calculation should be made. Please contact your installer or our local sales representative for more information concerning this.

Yes it is possible to replace your conventional radiator with a Low-H2O element. They both work with the same medium: hot water enters the element and emits heat to the room. Most important factors when replacing your existing radiator are: dimensions and heat output.

All Jaga Low-H2O cabinets (except Tempo) are available in standard white (RAL 9010) and sandblast grey colour. Besides this Jaga has many special colours and even all other colours can be custom made.

Download the Jaga Colour Chart here.

All cabinets are painted with a scratch resistant epoxy-polyester powder, sprayed electrostatically and baked at a temperature of 392°F. UV-resistance equal to ASTM G53. For the colored grills in the Mini Canals we use an extremely durable powder coating that is even more scratch resistant.

Thermostatic Radiator Valve, (TRV), is a self regulating valve fitted to hot water heating system radiators. The TRV controls the temperature of a room by regulating the flow of hot water to the radiator. TRV’s consist of two parts, a valve that opens or closes to control the hot water flow, and an actuator that controls the opening of the valve. The actuator adjusts the valve opening based on the temperature in the room via a mechanical linkage or pin connected to the valve. The actuator is usually a plastic unit containing a wax plug, the wax plug expands or contracts as the temperature of the room rises or falls. The plastic unit is preset by a screw mechanism that positions the wax plug a set distance from the connecting pin. It’s very much possible that the location of the room thermostat is colder than the kitchen. When you are not using a TRV, the element in the kitchen continues emitting heat. When using a TRV, the water flow is reduced in order to control the temperature. This not only increases the comfort level but also reduces the energy consumption.

Due to the application of the specially designed Jaga pre-settable Trv’s, the water flow (Kv) in the element can be perfectly adjusted for an optimal performance. The Trv with built in balancing control has two control possibilities. The first flow regulation can be controlled by the thermostatic valve. A setting from 1-6 can be chosen depending on the required flow. This setting limits the maximum flow to the radiator, which is determined by the location of the radiator in the heating circuit. The second control is executed by the thermostatic head which balances the flow between the newly set maximum and zero. This maintains a constant temperature in the room.
• Due to the correct quantity control of the required amount of water to the different heating elements energy is being saved.
• After the night period, when all Trv’s are fully opened, the balancing control allows the furthest heating elements to get the required amount of hot water.
• The water flow temperature can be reduced earlier because of the uniform heating up of all heating elements, which will restrict the energy loss.
• The noise of the flowing water will also be reduced thanks to the balancing flow control.
• The optimal water distribution allows the use of a smaller water circulation pump
• The water distribution to the different heating elements can easily be adapted when extending or changing the heating system.

Yes, Jaga heating elements are certified according the EN442 standard:
• Obligated standard, European radiators and convectors have to be tested accordingly,
• testing procedure includes Low- water temperature rating,
• tests at different flow rates,
• all elements are tested at minimal 3 different temperatures, allowing to generate an accurate graph for output determination at alternative water temperatures,
• several different heights are actually tested
• there is no addition to the measured output.
Jaga is working together with AHRI to develop a new IBR testing standard for Low- water temperatures.

This European standard is introduced in Europe to certify the output of all heat emitters for central heating systems. This standard Defines procedures for determining the standard thermal output of the heating appliances (radiators and convectors) fed with water or steam at temperatures below 248°F, supplied by a remote heat source. This also specifies the laboratory arrangements and testing methods to be adopted, the admissible tolerances the criteria for selecting the samples to be tested and for verifying the conformity of the current production with the samples. Guidelines for testing procedures and conditions are taken into this standard. All outputs are measured and certified for standard water and room temperatures. Standard inlet, return and room temperatures are: 167/149/68 , 194/158/68 and 131/113/68 °F. All alternative temperatures can be calculated according to realistic formulas and graphs. Also there will be tests performed on different products in the same product-range , this includes different flow rates and different cabinet heights. Due to the very strict structure of the test room, an exact reproducibility is obtained. There will be no extra addition to the measured results. All European manufacturers are obliged to participate in this testing procedure. A periodic recheck will be performed on a random selection of appliances. This standard ensures all users that the published heat outputs are officially tested and confirmed by an independent official laboratory.

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