What is the purpose of a dedicated outdoor air system?
DOAS and Dehumidification Instead it allows the local heating/cooling units to be sized smaller, and requires less valuable floor space.
What is the principal benefit of using a DOAS system?
Here are the main benefits discussed: DOAS provides better ventilation. Decoupling sensible and latent cooling functions of air handling systems. More freedom when selecting local units.
What does a DOAS do?
How Does a DOAS Work? A dedicated outdoor air system is an HVAC unit that is installed outside and is often used with other HVAC equipment. DOAS units bring fresh outside air into interior spaces independently from heating or cooling efforts.
What is meant by a dedicated vent system?
A dedicated outdoor air system (DOAS) is a unit supplying cooled, dehumidified outside air to the building in summer and heated outside air in the winter.
How much does a DOAS unit cost?
| Cost item | Unit cost | Cost savings |
|---|---|---|
| Ductwork | $1/sq-ft DOAS, $4/sq-ft VAV | $558,000 |
| AHU | $2/cfm VAV $4/cfm DOAS | $170,000 |
| Electrical Serv. | $50/kW | $12,400 |
| Facade/partitions | $35/ ft 2 of facade | $150,780 |
How can a dedicated outside air system DOAS save energy when used in conjunction with a central VAV system?
A dedicated outdoor air system (DOAS) supplies outside air to the terminal units in the building separately from the main supply air. This strategy allows for better humidity control, more precise air delivery, and decreased energy consumption.
What is the difference between DOAS and Ahu?
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.
Does a DOAS dehumidify?
A DOAS unit can also provide the dehumidified air directly to spaces at 55°F where it will offset some of the sensible load of the local HVAC unit. It is this technique that differentiates it from conventional HVAC systems. This configuration will cool and dehumidify air in the summer and heat or cool it in the winter.
What are the advantages of variable air volume air conditioning system?
The advantages of VAV systems over constant-volume systems include more precise temperature control, reduced compressor wear, lower energy consumption by system fans, less fan noise, and additional passive dehumidification.
Is an ERV a DOAS?
A Dedicated Outdoor Air System (DOAS) with a high efficiency Energy Recovery Ventilator (ERV) is an alternative ventilation system design that can significantly reduce a building’s heating and cooling loads and provide controlled and conditioned ventilation that improves indoor air quality and occupant health, while …