The equipment selection steps of fresh air unit are as follows:
1. Select the form of the new fan according to the installation Settings;
2. Determine the design conditions for cooling capacity and heat generation;
3. When selecting the air volume and wind pressure of the equipment, the principle shall not be less than the design value;
4. In principle, fresh air units are only responsible for the amount of fresh air required for a floor (definition: volume of air per unit time).
Suggestions on safe operation of fresh air units
1, the construction unit in winter construction of the fresh air unit of the anti-freezing problem is serious, pay attention to all air-conditioning equipment and pipeline anti-freezing. The key point of relative humidity control of fresh air unit is the location of humidity sensor or the selection of control parameters, which is related to the source and control mode of humidification. Pay attention to the outdoor air temperature during piping pressure test flushing, and ensure the complete system drainage after flushing and no safety hazards. The use of fresh air units for temporary heating should also be inspected and accepted in accordance with the normal procedures. If there is no automatic control measures and special management, it is not recommended to use fresh air air-conditioning equipment for temporary heating.
2. Bij het ontwerp van luchtbehandelingsunits dient een effectief automatisch beveiligings- en bewakingsapparaat tegen bevriezing te worden geïnstalleerd. Bij het bedienen van de ventilator moet eerst de nominale doorstroming van de verwarming worden gegarandeerd; wanneer de watertemperatuur te laag is of de waterstroom gedurende een bepaalde tijd onder de ingestelde waarde daalt, dient onmiddellijk de ventilator te worden uitgeschakeld en de luchtisolatie te worden ingeschakeld. Zonder adequate bescherming biedt het luchtventilatie‑systeem in feite slechts een halfafgewerkte oplossing; in koude streken mag een dergelijke unit in de winter zonder passende beveiliging niet operationeel zijn – dit is geen vrijblijvende “verantwoordelijkheid”.
3. Establish and improve the operation management system. The fresh air unit that stops at night should also use constant flow rate or temperature controller to automatically control the water valve to open or set up electric heating device to ensure the temperature of the fresh air unit heater. During the operation of fresh air units in winter, weather changes should be checked regularly. In cold weather, the commissioning and maintenance of the air-conditioning system should not be arranged to ensure the safe operation of the air-conditioning water system.
