Keyword Expression question - set boiler type

2 posts / 0 new
Last post

I am struggling to determine how to set a BOILER TYPE using a keyword expression.

If( x>Y) then

Christopher R. Jones, P.Eng.
Technical Specialist
Sustainability & Energy

[cid:image001.png at 01D3D6D5.E609DAE0]
T +1 416-644-0252

2300 Yonge Street, Suite 2300
Toronto, ON M4P 1E4 Canada

Please consider the environment before printing...


NOTICE: This communication and any attachments ("this message") may contain information which is privileged, confidential, proprietary or otherwise subject to restricted disclosure under applicable law. This message is for the sole use of the intended recipient(s). Any unauthorized use, disclosure, viewing, copying, alteration, dissemination or distribution of, or reliance on, this message is strictly prohibited. If you have received this message in error, or you are not an authorized or intended recipient, please notify the sender immediately by replying to this message, delete this message and all copies from your e-mail system and destroy any printed copies. You are receiving this communication because you are listed as a current WSP contact. Should you have any questions regarding WSP's electronic communications policy, please consult our Anti-Spam Commitment at For any concern or if you believe you should not be receiving this message, please forward this message to caslcompliance at so that we can promptly address your request. Note that not all messages sent by WSP qualify as commercial electronic messages.

AVIS : Ce message, incluant tout fichier l'accompagnant (? le message ?), peut contenir des renseignements ou de l'information privil?gi?s, confidentiels, propri?taires ou ? divulgation restreinte en vertu de la loi. Ce message est destin? ? l'usage exclusif du/des destinataire(s) voulu(s). Toute utilisation non permise, divulgation, lecture, reproduction, modification, diffusion ou distribution est interdite. Si vous avez re?u ce message par erreur, ou que vous n'?tes pas un destinataire autoris? ou voulu, veuillez en aviser l'exp?diteur imm?diatement et d?truire le message et toute copie ?lectronique ou imprim?e. Vous recevez cette communication car vous faites partie des contacts de WSP. Si vous avez des questions concernant la politique de communications ?lectroniques de WSP, veuillez consulter notre Engagement anti-pourriel au Pour toute question ou si vous croyez que vous ne devriez pas recevoir ce message, pri?re de le transf?rer au conformitelcap at afin que nous puissions rapidement traiter votre demande. Notez que ce ne sont pas tous les messages transmis par WSP qui constituent des messages electroniques commerciaux.


Jones, Christopher2's picture
Joined: 2017-10-12
Reputation: 0

I think boiler / chiller TYPE, like airside system TYPE, is something you can technically ?expressionize? via the eQuest interface, but you?ll find cirtical issues in simulation.

For primary equipment on hydronic loops, I much prefer to define for example

* +1 ?dummy? primary loop, of an appropriate type (hot water in this case). Give that a minor process load to avoid throwing errors in simulation
* Fully define your HW-BOILER and your ?other? boiler(s) as distinct boilers in the same model, but place them on the ?dummy? loop if they shouldn?t be active.
* With parametric run inputs, or with expressions, you can then ?swap? which boiler(s) are on your actual primary loop by swapping the loop assignments.

Another working approach I?ve heard of is to define all boiler options of interest on the same (actual) loop, but use expressions to toggle capacity down to zero (or near zero) vs. actual sizing, to effectively turn ON only the boilers that should be active. A little less work compared to a ?dummy? loop approach, but doesn?t afford the same ?spatial? sense of what boilers are active for a given run.


[cid:image002.png at 01D3D6FA.40CBEA30]
Nick Caton, P.E., BEMP
Senior Energy Engineer
Regional Energy Engineering Manager
Energy and Sustainability Services
Schneider Electric

D 913.564.6361
M 785.410.3317
F 913.564.6380
E nicholas.caton at

15200 Santa Fe Trail Drive
Suite 204
Lenexa, KS 66219
United States

[cid:image003.png at 01D3D6FA.40CBEA30]

Nicholas.Caton at's picture
Joined: 2016-02-26
Reputation: 0