[Equest-users] temperature dead band query

[Wolfe, Josh]

For CHW/HW the way I interpret the code is the cooling control valve cannot start to open to coil until at least 5F above the temperature at which the heating control valve starts to open to coil.

eQuest has a throttling range, so if you put a 75F cooling setpoint and a 70F heating setpoint the deadband will be less than 5F based on the throttling range input.

For example an input of 2R throttling range in eQuest, then one would need to use 77F for cooling setpoint and 70F for heating setpoint. Cooling would shut off completely at 76F and heating would shut off completely at 71F to achieve a 5F deadband.

Josh

From: Equest-users [mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of John Aulbach via Equest-users
Sent: Wednesday, September 19, 2018 10:57 AM
To: equest-users at lists.onebuilding.org; equest user <equestuser00 at gmail.com>
Subject: Re: [Equest-users] temperature dead band query

I will give this a crack, as it has been some time since i dealt with this.

The temperature deadback will be a 5 DegF band between heating and cooling. So your cooling t'stat setting in eQuest day schedule will be, say 75 DegF and heating t'stat at 70 DegF. Between those temps, no cooling or heating should take place.

Group, it isn't any more complicated than that, correct?

John

On Wednesday, September 19, 2018, 2:42:12 AM PDT, equest user via Equest-users <equest-users at lists.onebuilding.org<mailto:equest-users at lists.onebuilding.org>> wrote:



Hi all Modelers,



I am having a hard time understanding the below statement mentioned in my country's local guidelines. I assume it is pertaining to 4 pipe AHUs which goes as follows:



“All heating and cooling systems shall be temperature controlled. Where a unit provides both heating and cooling, controls shall be capable of providing a temperature dead band of 3 degree Celsius (5 degree Fahrenheit) within which the supply of heating and cooling energy to the zone is shutoff or reduced to a minimum."



Can anyone help me what exactly the guideline is referring to as “temperature dead band” and how can I verify it with my installed system (is it mentioned in AHU datasheets?).



My system is a 4 pipe units which provides cooling in summer and heating in winter season.



Eagerly waiting for your suggestions.



Thanks,

Tejas
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