How does DOAS unit work?

By conditioning the outdoor air and recirculated air independently, a DOAS unit effectively separates the sensible and latent loads. The outdoor-air DOAS unit removes the latent load to control humidity. The main HVAC unit then removes the sensible load to produce a comfortable temperature.

What is a DOAS in mechanical engineering?

A dedicated outdoor air system (DOAS) is a type of heating, ventilation and air-conditioning (HVAC) system that consists of two parallel systems: a dedicated system for delivering outdoor air ventilation that handles both the latent and sensible loads of conditioning the ventilation air, and a parallel system to handle …

What is difference between Ahu and DOAS?

In its simplest form, a DOAS is an AHU dedicated to ventilation, not sized to provide cooling air. DOAS often are supply-only systems with relief to outdoors; however, they also can include exhaust heat recovery.

What is a water source heat pump?

The water source heat pump replaces the outdoor fan and coil with a heat exchanger. For this system to work the building provides a loop of water. This water loop includes a cooling tower and a boiler to maintain the water entering and leaving the unit for optimal performance.

Does a DOAS need economizer?

Therefore, water-side free cooling (WSFC), or economizer, is thought to be required for practical DOAS applica- tions.

What is a DOAS terminal unit?

The DOAS unit provides the Designer, Owner and Occupant with a series fan powered terminal unit which includes an integral chilled water sensible only coil at the plenum air inlet.

What is outdoor air requirement?

ASHRAE 62 recommended minimum Outdoor Air Flow Range 15 – 60 cfm per person. Most common range 15 – 35 cfm per person. Average range 15 – 20 cfm per person.

How do water source heat pumps heat?

Water source heat pumps, on the other hand, work on basically the same principle as air source heat pumps, but they extract heat from a body of water rather than the air. They do this by cycling water through a system of pipes that is laid out at the bottom of a body of water.