issues with heating load

asked 2021-10-09 16:18:42 -0600

charlottenauss's avatar

updated 2021-10-11 08:54:23 -0600

My heating loads are way too low for a 12 story, 153 unit MURB, and there shouldn't be a heating load in July and August. I don't know where to start to look for where to fix this.

image description

*New HVAC load profile and HVAC system images

C:\fakepath\hvac load profile.JPG

C:\fakepath\thermal zones.JPG

C:\fakepath\ahu.JPG

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Comments

That isn't a lot to go on. I notice you tagged this as measure. If you did use a measure to make some portion or all of the model can you provide details. Also notice there isn't any cooling loads, maybe that is related to what is happening with heading loads. Also depending on your system you may have re-heat coils in terminals that would result in some heating load even in summer.

David Goldwasser's avatar David Goldwasser  ( 2021-10-10 18:53:04 -0600 )edit

yah I will make sure I include more next time. I did manage to fix the issue of the loads being too small, however I still have heating in July and August. This is the baseline building, and my supervisor does not want me to include cooling because it is not really necessary at the buildings location (Halifax Nova Scotia). The system uses baseboard electric heating paired with an AHU with a DX single speed heating coil, that heats the air to 65 degF, there is an AHU per floor and the parking levels are unheated. I attached more pictures above.

charlottenauss's avatar charlottenauss  ( 2021-10-10 20:28:18 -0600 )edit

I think it's important to point out that the "HVAC Load Profiles" chart is actually showing HVAC Energy (which of course the units imply) - it queries the monthly energy consumption for the Heating and Cooling end-uses, which include system efficiency. I think the use of 'load' in this section of the report is misleading as it doesn't conform to the common HVAC definition (i.e. heat addition/extraction required to maintain a specific interior conditio

ericringold's avatar ericringold  ( 2021-10-11 15:50:23 -0600 )edit

Okay but when there is no cooling, and the outside temperature is warm, the HVAC system should not need to use so much energy to maintain the zone temperature in the summer months

charlottenauss's avatar charlottenauss  ( 2021-10-11 15:57:19 -0600 )edit

I am using a scheduled setpoint manager for the AHU, should I instead use a different one?

charlottenauss's avatar charlottenauss  ( 2021-10-11 15:58:25 -0600 )edit