Bulk pumps: design, purpose, application in HVAC systems

In any climatic installations (fan coil units, chillers, monoblock air conditioners) associated with dehumidification or air cooling, condensate forms. It is most convenient to take it away, of course, simply “outside the window” - at the nearest point of contact between the room and the outdoor space, and from devices located outside the premises - generally “under oneself”. However, this is contrary to aesthetic, sanitary and building codes (even technical harm to various structures is possible). If in the domestic and communal sector such violations can (for quite a long time and unsuccessfully) be fought by operational and other services, then at enterprises the issue should be resolved in the only way:

• excess moisture must be drained and discharged into drains - centralized or arranged specifically for this purpose.
  

Pumps for pumping condensate should not provide significant pressure or performance: drainage lines rarely have lifts of more than one meter, the volume of moisture from the largest units (not counting very exotic objects) is only tens of liters per hour, and in the vast majority of systems under moderate conditions, not more than a litre. But there may be increased requirements for dimensions, aesthetics and noise characteristics - when the equipment is located directly in the front room or with a long stay of people.

For such purposes, pumps of a very different principle of operation can be used:

• piston (more rational to use for high pressures);
  
• axial (for high flow rates, not very clean liquids);
  
• centrifugal (compact and reliable, also uncritical to pollution);
  
• vibration (very cheap and small, but unreliable and noisy);
  
• rotary (a lot of advantages, but exotic, are used very rarely);
  
• peristaltic (primitive for young technicians, but serial ones also exist).
  

Due to the small volumes of condensate, and most importantly, its instability (even in the same installation with the same mode, the release of moisture varies depending on the environmental conditions), it is impossible to choose such a pump performance at which it would confidently cope with incoming water, but would never run dry. Automation is used (most often with a float sensor), which turns on the engine only when the liquid level exceeds a certain value. In most bulk pumps, the second (higher) level is also set - emergency, the achievement of which means that for some reason the pump did not turn on (or is faulty, or cannot cope with the volume) and the fan coil or other sources of condensate must be turned off.

 Since the constant start-stop mode is harmful to the engine, switching devices, pump impeller, the entire hydraulic system and even the electrical network, it makes sense to at least reduce the frequency of switching on / off. To do this, a storage tank is installed (in fact, the volume of the float chamber increases): the pump has to work longer, but less often. As a rule, there is more than one entrance to the tanks, since there are often several units in close proximity, from which a common tank can be used to collect condensate.

 Fancoil Motors provides an opportunity to buy from a warehouse in Moscow or order a filling pump for an air conditioner, including a multi-system type, for several fan coil units in an even wider range.