stumped re. excessive heating

6 posts / 0 new
Last post

I have a proposed building in a tropical climate with CHW cooling and

no heating. Per ASHRAE I'm installing electric heat in both the Baseline

and Proposed models. The heating in the Proposed is double what it is

in the Baseline. Worse yet, I am getting the following warning:

**WARNING*******************************************************************
***

ZONE EL1 East Perim Zn (G.E19)

might have insufficient heating capability.

Check that the SYSTEM or ZONE HEATING-CAPACITY plus this

ZONEs BASEBOARD-RATING is adequate to maintain the ZONE

specified DESIGN-HEAT-T for the calculated peak ZONE load

(see LS-A or LS-B for the ZONE peak load.)

SYSTEM UMA 102

which supplies the above listed ZONE, has a design heating

coil exit temperature, HEAT-SET-T,(plus any zone reheat)

below its MAX-SUPPLY-T or the ZONE DESIGN-HEAT-T, which

might account for the insufficient heating capability.

Does eQUEST overcompensate for an erroneous config for heating such that

it would behave this way? What should I look for?

Thanks in advance.

---

Christian Stalberg

Christian Stalberg2's picture
Joined: 2011-09-30
Reputation: 0

Christian:

Can you post your pd2 and inp files so we can take a look?

Paul Diglio, CEM, CBCP

Paul Diglio's picture
Offline
Joined: 2011-09-30
Reputation: 400

Here you go.

---

Christian Stalberg

Christian Stalberg2's picture
Joined: 2011-09-30
Reputation: 0

Christian:

Can you send the weather file also? I could not download from Does2.

Paul Diglio, CEM, CBCP

Paul Diglio's picture
Offline
Joined: 2011-09-30
Reputation: 400

Hi Christian

I did not have a weather file for Medellin but used one for Bogota. Wow Bogota is at an elevation of 8400 feet and its cold there.

Medellin is above 4000 feet (Not so tropical and heating is needed) you should use this altitude in your model (you currently have 0) this should allow eQuest to properly size the heat capacity for this altitude and your warnings should disappear.

Perhaps you should re-consider electric heat.

Hope this helps

-David

David C. Fishel, PE, LEED AP BD+C

David C. Fishel's picture
Offline
Joined: 2011-09-30
Reputation: 0

I used Botota for the weather file. For system
UMA 102, I changd the cool control to Warmest and
Heat Control to coldest and changed the reset
priority to Temperature First. The heating
energy is cut in half. Do that on all the
systems and you man chop all the heating in half.

The danger of self-sizing with program default is
you don't know what or why the results don't appear correct.

Chris Jones's picture
Offline
Joined: 2011-09-30
Reputation: 0