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For Real Fuel and Water Savings

Energy Efficiency Engineering


Heat Recovery Steam Generator

The ecoHRSG heat recovery steam generator is a further development of our innovative ecoFLUE heat exchanger .


The ecoHRSG  uses seamless carbon steel spiral coils as standard, suitable for steam pressure to 25 barg, maximum temperature 450 degC.

Go to the  ecoHRSG page.

THERMGARD has decades of experience with all aspects of equipment and systems for increased energy efficiency, higher plant productivity and improved maintenance outcomes in industrial and commercial plants.

Specialised knowledge of steam and condensate systems enables us to offer tailored solutions to the numerous challenges and problems faced by plant engineers and management.

From 1985 we pioneered the application of heat recovery from boiler blowdown in Australia, which can reduce boiler fuel costs by 5 - 10%. Invariably this also leads to better boiler water chemistry through automatic TDS controls, and additional savings in treated water costs due to condensation of the recovered flash steam in the feed tank or deaerator.

Deaeration of boiler feed water is another focus of our activities. We can offer both pressurised and atmospheric units.

We have been involved since the early 90's with recovery of waste heat from boiler stacks, when it was realised that conventional economisers had, frankly speaking, an unfavourable repution in many applications. This is due to the very real corrosion issues caused by condensing of acid vapours whenever the surface temperature of the economiser tubes drops below the acid dewpoint.

We initially developed our ecoDENSER system, which, by eliminating the corrosion problem, allows heat recovery down into the ambient temperature range. The ecoDENSER essentially converts an existing boiler into a condensing boiler, with fuel cost savings around 10 - 15%. More recently, our ecoDENSER design has been expanded for applications were primarily a wet scrubber is required for e.g. air  pollution control to remove solid particles and/or condensible vapours.

For smaller boilers and water heaters we developed our ecoFLUE heat exchanger. It also features all stainless steel construction and an internal bypass damper. It uses corrugated stainless tubing coils, identical to those used for solar water heaters, at economical prices.

We also offer a range of true in-line heat exchangers from ENERVEX, our partner in the USA. These excellent products feature an integral draft inducing fan to integrate  fully automatic draft control with the heat recovery package. It features removable radiator-style heat exchange coils for ease of cleaning, and an integral bypass damper.

Our association with ENERVEX began quite a few years ago when we realised that automatic draft control was essential for the vast majority of retrofit flue gas heat exchangers, since the lowering of the exhaust gas temperature, together with the pressure drop due to gas passage through the exchanger, reduces the natural draft considerably. By a happy coincidence, Steen Hagensen, President of ENERVEX, was just then on the lookout for flue gas heat recovery systems, and we were invited to contribute some heat recovery design packages. Since ENERVEX are the leaders in the field of automatic venting solutions, we are appreciative to now have access to their vast knowledge and equipment range. 

Condensate return system design requires practical experience to ensure that the plant operates safely and efficiently. Due to the two-phase flow occuring when condensate at steam pressure experiences a pressure drop, the layout of condensate piping is anything but straightforward. We have designed many systems that have in some cases been in continuous operation for in excess of 20 years, in industries such as corrugated cardboard, food processing and petrochemical. We have available specialised equipment which solves problems like water hammer and water logging, including automatic start-up valves, condensate lifting pots and our ecoLIFT steam or air-powered condensate pumps.

Dry steam is a requirement in processes such as autoclaves, plastic foam and rubber presses and molds, to name a few. By combining our ecoSEP steam separator with a downstream pressure reducing station and steam-jacketed delivery pipe, we impart superheat to the steam to prevent condensation right up to the point of application.

We pioneered the application of electrode-type self-checking boiler level controls in Australia from the1980's, originally with Gestra and more recently with Igema, both of which are in Germany. We are able to offer complete packages to convert boilers with on/off level control to modulating control. For boilers which operate more than one shift per day, this is justified by the economic benefits alone. Modulating level control also provides a remedy to upsets in steam supply caused by level surges, as well as reducing maintenance issues caused by relatively cold water slugs entering a boiler with on/off level control. We incorporate feed forward control from steam flow meters in applications where shrink and swell phenomena make straightforward proportional control less than ideal.


We are authorised by RTK (Regeltechnik Kornwestheim) to represent their products in Australia and NZ. Of particular interest are feed water control valves for modulating boiler level controls. These high quality valves feature an integral bypass to guarantee a minimum flow through the feed pumps. This feature eliminates the need for uneconomical orifice plates or unreliable minimum flow controllers.

Other products from RTK include self-acting pressure and temperature control valves, wafer-type check valves, and bellows sealed globe valves. In addition, RTK have available control valves with pneumatic or electric actuator for practically any application in the industrial and commercial HVAC market. An extensive range of instrumentation for level, flow, pressure and temperature monitoring and control allows the provision of complete control loops from one high quality source.

A system design approach sets us apart from other suppliers. Instead of simply offering hardware, we thrive on the challenge of integrating various equipment items into a complete package. Each application is evaluated individually to ensure that a comprehensive and complete system is presented to our clients, requiring the least amount of site work to complete the installation.

For Flue Gas Heat Recovery and Boiler Blowdown TDS Control and Heat Recovery, we have evolved standard modules which we can easily adapt to suit individual requirements.

For Condensate Return and Steam Distribution Systems, we generally include a site survey in our proposals to ensure that we fully understand our clients goals and objectives to arrive at the optimal solution from the points of safety, economy and productivity.


Deaerator and feed tank system packages are designed after all relevant information is collected, to ensure full compliance with statutory and customer requirements. To achieve this we have access to the latest design tools from a number of global sources.

In the Services section we highlight some of the tasks for which we are available to assist our clients. In some instances our clients prefer to choose their own suppliers of hardware, but would like to utilise our vast experience to write the specifications for specialised equipment, systems or sub-systems.

We can tailor our consulting services to any requirement. Site surveys for assessing new installation or replacements of steam traps and other equipment can be arranged, with the understanding that our recommendations will be free from bias since we are not associated with any steam trap manufacturer.

We receive regular enquiries from users of legacy equipment from e.g. Gestra, Igema, Cochrane etc., mainly to assist with sourcing of spare parts or replacement for out-of-date items. In many cases we supplied such equipment many years or even decades ago, and current agents and representaives simply don't have the access to archives to satisfy a clients requirements.

A specific example is the conversion of old Ogden condensate pumps from float operation to electronic control.


For some years we have received orders for supply of designs for our equipment and systems, mainly from countries other than Australia, where the shipping costs may be prohibitive or the client is a reseller expecting repeat business in his market. Examples include design packages including thermodynamic calculations and manufacturing drawings for flue gas heat recovery systems and boiler blowdown heat recovery systems.

We hope the information within these pages will be of interest, and look forward to being of service with any of your specific applications.

CONTACT US for further details.



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