[Equest-users] VAV with Electric Reheat

[Will Mak]

Could be a handful of factors but most of the control of the main heating coil with be the zone entering air temp/hot deck leaving temp input. Play with those numbers to match what the design should be and you should be able to get the results you are targeting.

 

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 <http://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: DongEun Kim [mailto:equested at gmail.com] 
Sent: Tuesday, June 28, 2011 12:31 AM
To: John Aulbach
Cc: Will Mak; equest-users at lists.onebuilding.org
Subject: Re: [Equest-users] VAV with Electric Reheat

 

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 <http://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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