Low energy buildings have been designed and built in such a manner to reduce the costs of operation, compared with civil engineering structures build in accordance with current standards and rules. These costs include, primarily, heating and ventilation, cooling of air in summer, service water heating, power and water consumption.

But what exactly does it mean in the Two Colour Letňany Project?

Two Colour Letňany Estate have been classified B-level, i.e. low-energy buildings (lower heat consumption than standard buildings in B category, in accordance with the energy label of the building.

In the Two Colour Letňany Project, this has been achieved by Porotherm insulation brickwork and triple-glassed plastic windows guaranteeing almost perfect thermal insulation of our new houses. The air handling system guarantees pleasant environment with minimum costs.

Air handling and heat recovery

Whereas previous civil engineering projects accepted air change through leaky windows, contemporary apartments in low energy houses are almost hermetically closed units, where adequate air exchange is provided by air handling system.

Thanks to heat recovery, fresh air is heated by exhaust air, thus reducing heat losses caused by ventilation. The heat generated in the apartment remains in the interior and fresh air from outside is pre-heated to pleasant temperature.

Each heat recovery unit has additional electric air heating system, which is sufficient for heating low energy apartment with minimum power consumption.

Efficient air handling system with heat recovery unit guarantees air exchange amounting minimum 10 per cent of air volume in the apartment each hour. Hence, whole air in the apartment will be changed in ten-hour´s time, which significantly improves air quality, both in terms of carbon dioxide content, smell and air moisture. The entire system is controlled and its performance can be increased several times.

Two separately adjustable subsystems are installed in each apartment, the one removing air from the kitchen and the other from other rooms. For instance, you can boost air exhaust from the kitchen during your cooking, while allowing minimum ventilation of other rooms.

A new feature of the 2nd project stage is extension of the air handling unit to add cooling system of incoming air in summer ( by approx. 10°C, which is substantially more favourable for human health than air-conditioning). In the 2nd project stage, the air handling unit has been inter-connected, i.e. booth functions (cooling and heating) are integrated in one system. Local electric air heating units installed in all apartments allow additional heating of incoming air.

All benefits of this system will become apparent only by personal experience of every occupant, nevertheless, it is sure that this system will increase living comfort in the apartment. And we also have received only positive feedback from the occupants for the following reasons:

  • No ventilation ´shocks´ - you avoid thermal differences, which means not only increasing you living comfort, but also benefit for flowers sensitive to temperature changes, for instance.
  • Fresh air is pre-heated by exhaust air, i.e. significant reduction of heating costs.
  • Air exchange can be controlled. At minimum setting, 10 per cent of air will be changed in the apartment every hour, which guarantees pleasant environment, without dust and moisture, but also without feeling air flow in the room.
  • Air handling system significantly improves hygienic comfort – no fogged windows, no moist in room corners and, hence, no mould.
  • Removing air from the kitchen – ventilation of the kitchen entire space, not only above the cooking stove. Of course, you can install circulatory cooker hood with carbon filter above the cooking place for local filtration of cooking fumes.
  • No noise generated by the system – there are no fans in the apartment and air-handling units are installed on the roof of every apartment house.
Download documentation of heat recovery units

Fired bricks – time-tested quality

To obtain ideal building static parameters, green houses in Letňany are made of quality fired bricks, starting from the first storey. Even in the age of alternative building materials, fired bricks maintain their privileged position, first of all, owing to high quality and long-time durability. They have been used for thousands of years and even now they are highly appreciated as a building material with excellent properties.

Made by one of the most significant manufacturers, the bricks used for construction of the Two Colour Letňany Estate are ideal choice for low energy houses. Well-tried material, sophisticated perforation system and, last but not least, processing quality make Porotherm brick indispensable component of any high-quality and cost-effective building project.

Benefits of houses made of bricks:

  • Natural thermal insulation. Ability to accumulate heat
  • High moisture resistance, unrivalled durability
  • Excellent technical parameters in terms of acoustics
  • Constant volume

Triple-glassed plastic windows

Plastic windows become ‟green ‟ standard in most of new houses now, yet, we are again a step ahead of the competition, thanks to offering triple-glassed windows to our customers. Compared with double-glassed windows, they guarantee better thermal insulation and unmatched parameters vs conventional windows.