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How to add extra heating system?

asked 2016-01-18 08:42:06 -0500

Dubravka's avatar

updated 2016-01-18 09:03:44 -0500

Hello! I am trying to make an energy model of existing building in OS. For the heating of the building is used district heating with HW baseboards. In winter months (December, January and February) employees use electrical heaters to sustain heat comfort and increase temperature for 2-3 degrees. Can you help me how to include this in my model? I have tried and end up with decreased DH consumption, but I want DH to stay the same and just to add more electricity consumption for extra heating. Thank you in advance. Dubravka

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answered 2016-01-18 14:55:03 -0500

On the Zones tab you can specify multiple pieces of zone equipment in addition to any air-loop connections you might have specified in the HVAC tab. If you scroll to the bottom of the Library pane in the Zones tab you'll see several Baseboard Radiant and Convective options that can be dragged into your zones.

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This is the correct answer in my opinion, but with one little wrinkle. By default HVAC components are autosized in OpenStudio, meaning that first component is going to pick up all of the load and the supplemental space heater will not do anything. To work around this you might hard size the primary system, leaving some unmet hours for your secondary space heater to pick up.

Kyle Benne's avatar Kyle Benne  ( 2016-01-18 15:44:09 -0500 )edit

Thank you for the answer. I wasn’t clear enough with my question. My problem is not adding second piece of equipment but how to control working of two pieces of equipment. I have tried @Kyle Benne proposition to hard sized one system (I am not sure how OS chooses system to become primary or secondary system). I end up with nearly the same result but with more unmet hours. I was wondering is there a way to make a schedule in which I could choose when secondary system would start and increase temperature achieved with primary system?

Dubravka's avatar Dubravka  ( 2016-01-19 11:04:28 -0500 )edit

answered 2016-01-18 12:49:03 -0500

Rohini's avatar

I am assuming E+ does not allow you to add one more heater in the space in addition to the baseboard. If you know how much is the extra electrical energy, you could add it as a misc load in the spaces. You will have to change the heating thermostat setpoint to higher value that you are seeing in the spaces.

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Zones want to be attached to only a single air loop, but you can have multiple pieces of zone equipment attached to any zone along with an air loop connection - if appropriate.

ljbrackney's avatar ljbrackney  ( 2016-01-18 14:58:57 -0500 )edit

Thank you for your answer, that is one way to overcome my problem, but I was hoping for some solution that would reduce the 'not comfortable time'.

Dubravka's avatar Dubravka  ( 2016-01-19 11:11:20 -0500 )edit

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Asked: 2016-01-18 08:42:06 -0500

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Last updated: Jan 18 '16