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how to find out standard cooling tower leaving temperature(condenser Entering temperature, or CWST)

asked 2019-12-11 19:45:06 -0500

Mr.HA's avatar

ASHRAE 90.1 Large office Prototype building, tower leaving temperature(Condenser entering temperature) is 21.1 celcius temperature have been entered into. What literature and standards are these and criteria set?

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answered 2019-12-13 10:51:33 -0500

Jian Zhang's avatar

The ASHRAE 90.1 Large Office Prototype models (https://www.energycodes.gov/developme...) are being updated for the upcoming 90.1-2019 savings analysis. We are making changes to the cooling tower modeling strategies on tower design/sizing and operational control inputs. There are differences between 90.1-2010 App G G3.1.3.11 and later editions, for example 90.1-2016 G3.1.3.11. Since the design and controls specified in the newer editions are not in the prescriptive requirements yet, we decided to use the following 90.1-2010 App G rules:

The condenser water design supply temperature is either 85 deg. F or 10 deg. F approaching design wet-bulb temperature with a temperature rise of 10 deg. F

The tower is controlled to maintain a 70 deg. F leaving water temperature.

When using CoolingTower:VariableSpeed to implement these rules, we found the following built-in limitations in EnergyPlus The design inlet air wet-bulb temperature to be lower than 20 deg. C, this limit is set in the IDD. The design inlet air wet bulb temperature bounds for the CoolToolsCrossFlow model are -1.00 and 26.67 deg. C. The approach temperature to be lower than 1.11 deg. C or higher than 11.1 deg. C

So, if you'd like to follow this method, the notes above might be helpful.

Thanks,

Jian

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Asked: 2019-12-11 19:45:06 -0500

Seen: 125 times

Last updated: Dec 13 '19