[Equest-users] VAV with Electric Reheat

[DongEun Kim]

Dear Will,

Thank you for your help on this!!

The result was exactly as you mention below.

But, why can't  main heating coil work to meet the zone heating load if the
reheating coil does not work ?

~DE

2011/6/28 John Aulbach <jra_sac at yahoo.com>

>  Sorry, Dong, if I did not interpret your question correctly. If you have
> a VAV system with reheat, you will ALWAYS have the reheat available, even if
> just in a space heating sense (in winter months).
>
> You cannot change SYSTEM types in eQuest by Season. You are stuck with
> reheat (especially if electric). But IF you had Hot Water reheat, you COULD
> schedule your boiler off when you don't want the rehat to work.
>
> Result? Your SYSTEM will try to reheat cold zones, and be unable to. You
> will get zones whose load you cannot meet as the power behind the reheat
> isn't there.
>
> The DOE-2.2 engine behind eQuest combined the old SYSTEM and PLANT into
> HVAC. NOW, if your plant does not have the capability to heat or cool, space
> temperatures will rise. That wasmn't true in DOE-2.1E.
>
>
>  ------------------------------
> *From:* DongEun Kim <equested at gmail.com>
> *To:* John Aulbach <jra_sac at yahoo.com>
> *Cc:* Will Mak <wmak at epsteinglobal.com>;
> equest-users at lists.onebuilding.org
> *Sent:* Mon, June 27, 2011 6:06:41 PM
>
> *Subject:* Re: [Equest-users] VAV with Electric Reheat
>
> Let me re-direct my question regarding reheating:
>
> How do I make my reheating (electric) work only(mainly) for cooling mode?
> ~DE
> 2011/6/27 John Aulbach <jra_sac at yahoo.com>
>
>>  DongEun:
>>
>> There is no difference, except to make the secondary heating coil
>> ELECTRIC. No problem in eQuest.
>>
>> John Aulbach
>>
>>
>>  ------------------------------
>> *From:* DongEun Kim <equested at gmail.com>
>> *To:* Will Mak <wmak at epsteinglobal.com>
>> *Cc:* equest-users at lists.onebuilding.org
>> *Sent:* Sun, June 26, 2011 9:19:02 PM
>> *Subject:* Re: [Equest-users] VAV with Electric Reheat
>>
>> Will,
>>
>> If I understand correctly, reheat Delta T, which was to specify  max
>> reheat coil capacity.
>>
>> What I want is to switch reheat source from 'how water' to 'ectricity',
>> while the heating source for
>>
>> the main heating coil is 'how water.'
>>
>> Thank you.
>>
>> ~DE
>>
>> 2011/6/24 Will Mak <wmak at epsteinglobal.com>
>>
>>>  You have to put a value for the reheat delta T or the reheat coils
>>> don’t kick on.****
>>>
>>> ** **
>>>
>>> *William Mak, LEED AP BD+C*
>>> Mechanical Design Engineer
>>>
>>> *EPSTEIN*
>>> Architecture
>>> Interiors
>>> Engineering
>>> Construction****
>>>
>>> Sustainability
>>>
>>> 600 West Fulton Street
>>> Chicago, Illinois 60661-1259
>>>
>>> D: (312) 429-8116
>>> F: (312) 429-8800****
>>>
>>> E: wmak at epsteinglobal.com
>>> W: www.epsteinglobal.com
>>>
>>> þ Epstein is a firm believer in sustainability. We ask that you please
>>> consider the environment before printing this e-mail.****
>>>
>>> ** **
>>>
>>> *From:* equest-users-bounces at lists.onebuilding.org [mailto:
>>> equest-users-bounces at lists.onebuilding.org] *On Behalf Of *DongEun Kim
>>> *Sent:* Thursday, June 23, 2011 11:58 PM
>>> *To:* equest-users at lists.onebuilding.org
>>> *Subject:* [Equest-users] VAV with Electric Reheat****
>>>
>>> ** **
>>>
>>> Hi all,****
>>>
>>>  ****
>>>
>>> Can anyone give me an advice regarding a problem described below?****
>>>
>>>  ****
>>>
>>> I need to model a VAV system with chilled water coil and hot water coil,
>>> and also with Electric Reheating.****
>>>
>>>  ****
>>>
>>> As a start,  I selected  'VAV with HW Reheat' system.****
>>>
>>>  ****
>>>
>>> However, I've realized that the system only generates a reheating coil
>>> without a main hot water coil(heating coil).****
>>>
>>>  ****
>>>
>>> So I installed  'heating coil'  in the detailed mode, and then, I  changed
>>> the zone heat source to be 'electric'.****
>>>
>>>  ****
>>>
>>>  ****
>>>
>>> However when I take a look at the result, there came two problems.****
>>>
>>>  ****
>>>
>>> 1. Heating was mainly done by reheating coil not by main heating coil.**
>>> **
>>>
>>>  ****
>>>
>>> 2. Reheating didn't seem to use electricity.****
>>>
>>>  ****
>>>
>>> Any advice will be greatly appreciated.****
>>>
>>>  ****
>>>
>>> Thank you in advance.****
>>>
>>>  ****
>>>
>>> ~DE ****
>>>
>>>  ****
>>>
>>> Kim, DongEun(DE) | Research Engineer, LEED AP
>>> Annex R&D Institute, HIMEC(Hanil Mech. & Elec. Consultants)****
>>>
>>>  ****
>>>
>>
>>
>
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