{"id":3152,"date":"2013-09-09T14:18:11","date_gmt":"2013-09-09T14:18:11","guid":{"rendered":"https:\/\/informatech.energir.com\/?p=3152"},"modified":"2021-04-15T15:31:28","modified_gmt":"2021-04-15T20:31:28","slug":"energy-recovery-on-air-air-ventilation-systems-under-winter-conditions","status":"publish","type":"post","link":"https:\/\/informatech.energir.com\/?p=3152&lang=en","title":{"rendered":"Energy recovery on air-air ventilation systems under winter conditions"},"content":{"rendered":"

The primary goal of a heat recovery unit in a North American climate is to minimize the cost of heating fresh air.<\/p>\n

In a cold climate, operations may be carried out below the freezing point. To protect operations and avoid complications, freeze-prevention methods are used, which reduce system efficiency.<\/p>\n

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These prevention methods may thus have an impact on overall heating consumption and on operating costs.<\/p>\n

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Performance and climatic conditions<\/p>\n

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\nThroughout the winter, energy recovery is done by exchanging heat from the warm fluid (the stale air from the building) toward the cold fluid (outside air introduced). A good design must take into account the possibility of ice build-up on the airflow side, which loses heat during cold winter temperatures. In this regard, the at-risk side is the stale air side.<\/span> <\/span>
\nThermal exchange diagram<\/span> <\/span> <\/span>
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The formation of ice on a heat exchanger reduces the exchange surface. The flow of air required by the building may thus be reduced, as well as the efficiency of the recovery system. Also, the condensate needs to be drained when it defrosts or when it remains in its liquid form.<\/p>\n

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There are several methods for preventing icing. The main ones are:<\/p>\n

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