A recuperator made from inexpensive and available materials suitable for flats and homes with a need for frequent ventilation.
A wide range of central and local recovery units using the thermal capacity of the exhaust air, can be found on the market, but at the cost of thousands to tens of thousands of crowns, which outstrips the financial capabilities or needs of customers. Economically efficient building insulation + well-sealed windows (especially plastic windows) regularly reduce the spontaneous exchange of air, thus increasing the need for ventilation. The same applies to workshops, cellars, bathrooms, store rooms, and other rooms.
The basis for the heat exchange surface is formed by goosenecks, storedheld? installed? in a supporting cylinder ( plastic sewer pipe, 20 cm in diameter, 1 m long) + small 12V fans + an adapter .
The goosenecks are threaded through an expanded polystyrene foam disk and then fixed in place with insulating spray foam. The resulting unit is inserted into the pipe and sealed at the ends. Two 70 mm pipes are inserted through the building’s walls and the recuperator is affixed to them with foam sealant at the point where they exit the building.
Additionally, the plastic structure makes it possible to supplement the outlet channel (the original warm airstream from indoors) with a manually or even thermostatically switched heating element, thus making it possible to extend the recuperator’s use during periods of frost and in significantly colder areas.
Altogether there are 70 pieces of tubing contained in the recuperator’s total length of 110 cm, giving an exchange surface area of over 5 square metres.
Efficiency is around 70% and it can be increased by reducing the capacity of the fans, which is particularly effective on frosty days. The device weighs approx. 7 kg. It replaces air at a rate of about 500 l/min. Efficiency is at about 90%.
The warm room air flows out of the 10/16 pipes, where it may condense. The resulting water drips onto a slanted cylindrical casing and leaves through the openings of the fan that draws air out of the room.
The recuperator may freeze during very cold periods. Frost can be removed by short discharges of warm air from the room, using both openings simultaneously.
In operation, the device significantly reduces indoor humidity, mainly in periods of frost. This effect can be used for such tasks as drying out basements, but in contrast, in residential rooms (eg. a block of flats) it may become necessary to humidify the air.