## How does demand control ventilation work?

Demand controlled ventilation (DCV) is a feedback control method to maintain indoor air quality that automatically adjusts the ventilation rate provided to a space in response to changes in conditions such as occupant number or indoor pollutant concentration.

### How much is a DCV?

\$300 to \$1000 per room
DCV costs of \$300 to \$1000 per room are typical, where the variation is due to the unique design of each building.

#### What are the three types of ventilation?

There are three methods that may be used to ventilate a building: natural, mechanical and hybrid (mixed-mode) ventilation.

How do you calculate demand control ventilation?

With a design population of 80 and a floor area of 1000 ft², the design ventilation rate (DVR) is 660 cfm of outdoor air. DVR = (VP × P) + (VA × A) DVR = 7.5 cfm/person × 80 people + 0.06 cfm/ft² × 1000 ft² = 660 cfm Here, the classroom receives 8.25 cfm/person [585/80 = 8.25].

What is the advantage of incorporating demand operated ventilation in civil designs?

By reducing average airflow over the year, demand controlled ventilation permits a reduction of the demands placed on the exhaust fan, and thereby increases its longevity.

## What are the 2 types of ventilation?

The two main types of mechanical ventilation include positive pressure ventilation where air is pushed into the lungs through the airways, and negative pressure ventilation where air is pulled into the lungs.

### What is the best type of ventilation?

Supply ventilation: Fresh outdoor air is pulled in through air intake vents and is distributed to points throughout your commercial facility by a powerful fan and a ductwork system. This type of ventilation is most effective in hot or mixed-temperature climates.

#### Which type of sensor is typically used with demand ventilation?

The sensor used to adjust the ventilation rates is most commonly a CO2 sensor that is hyper sensitive to CO2 levels in the air.

What range would CO2 be controlled to for a space set point?

When designing a DCV system with CO2 detectors, one of the first design requirements is setting the optimal CO2 setpoint. Standards from OSHA and other organizations normally set a limit of 5,000 ppm, while Canadian standards establish a lower limit of 3,500 ppm.

How much CFM do I need per person?

Occupancy method Example: For an office, the recommended ventilation rate is 20 cfm per person. The occupancy of a general office is one person per 80 to 150 sq. ft.