HVAC heating only doesn't do anything.

asked 2018-02-26 10:06:48 -0500

Mans_sopers's avatar

updated 2018-02-26 11:45:11 -0500

I'm trying to simulate a multi-room building with several electric furnaces of a building that is only occupied once a week. To simulate this, I added several electric furnaces (they don't have the same power) and added the related zones to the HVAC systems. Furthermore, I made different thermostat schedules by setting the heating thermostat at 0 degrees C as standard and priority 1 15 degrees celcius every Wednesday (the day is random, just wanted it to run once every week). I set the cooling thermostat standard on 100 degrees C, since there is no cooling done.

When I ran the simulation, I didn't see any noticable difference compared to other days of the week. Even increasing the heating capacity from 2000W to 20,000W didn't make a difference.

The only room that seems to do what it needs to do is the room with also a cooling unit. I did exactly the same thing there as for the other rooms, apart from a more reasonable cooling thermostat ofcourse.

Does anyone know what the problem could be?

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What is the temperature in the rooms that don't turn on heating? If < 15C then what system type are you using?

rraustad's avatar rraustad  ( 2018-02-26 10:45:33 -0500 )edit

Temperature differs along with outside temperature. So sometimes they are below 15C (temperature set of the Netherlands is used). For the rooms that do not turn on heating, I only use an electric furnace. Some of them are with a fan, others without.

Mans_sopers's avatar Mans_sopers  ( 2018-02-26 11:47:03 -0500 )edit

Did you look at the temperature of the spaces? What specific zone object are you using to model the electric heaters? Are your sizing runs assuming the space is at 15C or 0C?

mdahlhausen's avatar mdahlhausen  ( 2018-02-26 12:27:17 -0500 )edit

After running the model I looked at the temperature of the spaces if thats what you mean. It looks like no heating is done at all.

And sorry if I don't understand, I'm still a beginner, but do you mean what type of heater? It is an electric coil heater (some with and some without fan).

For the sizing runs do you mean the design days? I'm sorry, but the HVAC section is still a bit complex to me.

Mans_sopers's avatar Mans_sopers  ( 2018-02-26 14:11:21 -0500 )edit

If you mean the Heating Sizing Parameters or Cooling Sizing Parameters, I did not change them. For heating, the Zone Heating Design Supply Air Temperature is now set at 40C for each room. But this still confuses me on why the room with cooling and heating works and the others do not.

When I look at the results, at the table Zone Sensible Heating, it shows that the Thermostat Setpoint Temperature at Peak Load is 0C for all the rooms. It does give 15C for the room that works. Which makes absolutely no sense to me, since I did exactly the same for both rooms.

Mans_sopers's avatar Mans_sopers  ( 2018-02-26 14:18:29 -0500 )edit