Need Help with HAP load calculation 2

[edjenyo]

I have provide a load calculation for a building which is supposed to have a chiller plant to provide cooling through a fan coil unit and an AHU system to provide just fresh air(outdoor air ventilation) through diffusers. some amount of chilled water will be supplied to the AHU to have the outdoor air treated. I have been using carrier HAP and my challenge is how to go about the system properties i.e equipment type and air system type. i am not sure if this was right but i created two systems
(1)- air system name= fresh air system
- equipment type= Chilled water AHU
- air system type= CAV tempering ventilation
Then i added spaces that required just fresh air in the zone component tab

(2))- air system name= cooling system
- equipment type= terminal units
- air system type= 2 pipe fan coil
Then i added spaces that required just cooling in the zone component tab.

Thereafter, i created a plant name and chose generic chilled water plant as the plant type. i added the two systems and generated a report.

After these whole process, i was made to understand my load was duplicated,seemed to be too high.
please i really need your input and correction on this.

 

[Drazen]

I have no approach to HAP currently, but you should have maintained link with their support.

From my memory, this "tempering CAV ventilation" is questionable - what is that tempering? That should be something like "single zone CAV" or similar.

Anyhow, each field has to be understood and verified by yourself, to get valid result.

 

[DRWeig]

Yes, your system descriptions sound OK to me. The problem may be in the details, if there is indeed a problem.

i was made to understand my load was duplicated,seemed to be too high

How were you made to understand this?

1. Check the design criteria you entered for your tempering ventilation system, especially its supply air setpoint.

2. Choose one room and use the supply air CFM that HAP calculates for loads. Do a manual calculation to compare and look at the differences, if any.


4. If no solution (or proof that your answers are OK) becomes apparent, do what Drazen said. E-mail tech support. As long as your HAP license is valid, you'll get a good answer very quickly. You should have the e-mail address, and be sure to include your customer account number.

Best to you,

Goober Dave

Haven't see the forum policies? Do so now: Forum Policies

 

[cdxx139]

Your load is doubled? Make sure when you created the Plant, you didnt add the system twice. Common problem.

knowledge is power

 

[edjenyo]

@DRWeig thanks for the piece.

The setpoint was generated by the software and i never changed it.However i assume i was supposed to create just a system
(i.e CAV single zone) for cooling and outdoor air. With my license still valid, i hope the tech support would come in useful

thanks