Fresh Air Unit supply fan power

2 posts / 0 new
Last post

Hi, Everyone,

I'm modeling a VRF system with 30% extra fresh air as per ASHRAE standards.
The building has a Fresh Air Unit (without cooling coil and Heat recovery
wheels) which is supplying calculated amount of fresh air to VRF indoor
units.

As the Fresh Air Unit does not have cooling coil and heat recovery wheels,
entire cooling load of fresh air will be taken care by VRF indoor units.

I am doubtful about the Fresh Air Unit supply fan power. How should I model
the fan power of Fresh Air Unit supply fan? Should I break the fan power and
add it with the VRF indoor unit fan power as per the fresh air fraction
provided in that VRF unit?

Thanks in advance!

Regards,

Anil Jangid

Project Engineer

Aniljangid's picture
Offline
Joined: 2014-07-28
Reputation: 0

Anil,
Adding a Dummy zone you can try by putting it as Unit Ventilator and make the heating source as "not installed". Assign the fan schedule and input Design supply fan .....kw/cfm in fan power parameters.

Soham Babu | Project Lead

[setty-logo]

| Fairfax, VA | Washington, DC | Baltimore, MD | New York, NY | Mysore, India
| M/E/P/FP Design Engineering | Project Management | Energy Management Services | Construction Management | Design-Build Services | Commissioning
| Voice 703.691.2115 Ext. 135 | Fax 703.691.8084 | Cell 984.411.2737 | soham.babu at setty.com | www.setty.com

This e-mail and any files transmitted with it are confidential and are intended solely for the use of the individual or entity to whom they are addressed. If you are NOT the intended
recipient or the person responsible for delivering the e-mail to the intended recipient, be advised that you have received this e-mail in error and that any use, dissemination, forwarding,
printing or copying this e-mail is strictly prohibited.

Soham Babu's picture
Offline
Joined: 2011-09-30
Reputation: 0