Innovation provider

Elysium OÜ


Merivälja tee
111911 Tallinn
tel. +372 681 6800
fax +372 681 6801
gsm +372 510 0690
Contact person: Henri Kruusel


Within the last few years the heating rates have increased enormously. To lower the financial pressure on housing co-operatives, Elysium LCC has developed a Heatcatcher system. The principal of the product is to save the departing heat and use it for central heating system and/or heating up domestic water.

On the roof of the building’s ventilation chimney Heatcatchers are installed which consist of ventilators, dampers and air-water heat-exchangers.  On ventilation chimney a forced outflow is built, where each flue can be adjusted with the dampers, for example in accordance with the standards (e.g. 20 l/s). This will help to solve problems with the efficiency of natural ventilation that depends on many aspects: number of storeys (length of the flue), wind (strength, direction), temperature difference (internal and external), over- and under-ventilation and loss of heat. Heatcatcher can be tuned to fit these changing factors reactively and dynamically. Heat carrier (e.g. coolant) circulating in heat exchangers provides a year-round input to the heat-pump (for example it can be installed into the heat-unit). The system is installed on the top of the roof and its operation does not disturb the residents.


Heatcatcher is a system that can be installed to bigger buildings (block houses, multi-storey apartment buildings) and dwellings that are older – a part of housing stock very common in Estonia and other former Soviet countries. The product considerably decreases heat loss via natural ventilation system and has reasonably short payback time.

Innovative aspects (ecologic, social and economic)

Environmental aspects
The heat loss occurring with natural ventilation makes up 30-50% of heat balance of the building (percentage depends on how well the building is insulated). When that energy is used for heating up the apartments and hot water instead of letting it escape from the building, substantial amount of energy is saved.

Social aspects
Installing a Heatcatcher system improves the indoor climate and helps to solve ventilation problems that are very common for multi-storey apartment buildings. Both over- and under-ventilating are avoided: that way the indoor temperature does not get inconveniently cold (that would be the case when over-ventilating) and at the same time humidity is kept under control and oxygen levels sufficient. The freshness of air (oxygen content) is important because in rooms with poor oxygen people get tired more quickly and cannot get a good rest. In under-ventilated rooms there can be problems caused by excess humidity, e.g. mold and fungus and other microorganisms that can cause allergies and asthma and may also damage building’s constructions and refinement.
As the system is built on natural ventilation, air circulation does not stop in case of e.g. power cut.

Economic aspects
Instalment of Heatcatchers does not increase the spending, i.e. at first an investment must be made, but savings that are achieved later cover all these costs. It is also possible to apply for financial support from national funds for this kind of energy efficiency and micro climate improvement projects.
The average reduction in the share of district heating is 45-60% and the payback period at today's price level is less than 10 years.

Application examples

At the moment Heatcatcher is installed at three apartement houses in Estonia (Tallinn, Paide and Järvakandi).


The average cost per apartment is less than 1600 euro. Size of the investment per apartment depends on whether the house is smaller (has less than 60 apartments), in that case the cost is slightly higher. Maintenance costs are the same magnitude as the thermal node maintenance costs (depending on building size, etc.)

To reduce cost for clients it is also possible to apply for financial support from national funds for this kind of energy efficiency and micro climate improvement projects. For bank loans there is a guaranteeing system set up through KredEx.


Current stage of development

Already on the market

Intellectual Property Rights

Patent applied for, Patent granted, Trade mark
Patent granted in Estonia, patent applied for in Europe. Trade mark Heatcatcher is registered in Estonia and will be registered in Europe in the near future.

Country of origin


Country of application




National Contact Point

Antti Roose
Tartu Ülikooli, Geograafia Osakond
Vanemuise 46
51014 Tartu

Tel: +372 737 6841
Fax: +372 7375825