Question-and-Answer Resource for the Building Energy Modeling Community
Get s tarted with the Help page
Ask Your Question
2

HVAC for PassivHaus

asked 2017-02-20 16:37:37 -0500

Shawn gravatar image

updated 2017-02-23 17:00:03 -0500

I am trying to simulate a PassivHaus in EnergyPlus via OpenStudio and I am finding several problems with that. I tried with the following layout, but it doesn't do anything. I want to keep the inside temperature about 18-20ºC always, working with a heat exchanger using the exhaust air to preheat the outdoor air.

I attached a few images about I want to do.

My layout:

My layout

What I want to represent:

picture

Another one:

Edit -----

Okay, now, I've included the ERV in my ThermalZone, and edited it. I found some problems here...

  1. The first one. I don't know how to draw the airloop to add the ERV. I tried to add it in the one I posted (Link “My layout”) but I got a failed simulation. I am so lost here.
  2. When I am editing the control of my HVAC, I selected "Siempre 20º" (Always 20ºC), but in the results I don't get that. The temperature comes from 10 to almost 30ºC.
  3. When I am trying to edit the ERV, the Air Inlet Node Name and Outlet have a very strange name, so I can't identify the correct ones. In addition, I don't have the proper air-loop to know that nodes.
  4. Another question that I have is about the schedule that I need for Heating Thermostat and Cooling Thermostat. Should I use time? temperature? always on?
  5. I don't know either what type of SetPointManager use to set the temperature always in range between 18-24ºC

I am working with OpenStudio since November for my Final Project, and this is a completely chaos.

I put some links to helpful screenshots of what I want to explain.

image description image description image description image description image description

Edit 2 ------

I've deleted the air-loop, inserted a Recovery Ventilator in the Zone Equipment. But now, when I try to simulate, I get an error that didn't happened before... It says: Object=Wateruse:connections, name=Water use connection, Required Field=Water Use Equipment 1 Nambe (was blank)..

I've checked all the water system and the equipments has name. I am so confused cause I dind't change anything else and this error appeared.. Here some image references.

image description image description image description image description image description

Edit 3 -----

I've solved the Water Equipment error. When I deleted the old thermal zone, it disappeared from Spaces, thats all. Now I can run the simulation, but, I get the same results than before... Minimums temperatures of 14ºC and maximums of 28ºC (average), with the same graph. I tried to activate cooling and heating system from ERV's options (cooling setpoint 24ºC and heating setpoint 18ºC) but the temperature doesn't change anything... Any suggestion?

Apart from that, how can I know that this nodes are the correct ones (Air inlet/outlet)? Which ones should I select?

image description image description

edit retag flag offensive close merge delete

Comments

Welcome to UH! I fixed your post by adding the images directly in your post and removing greetings.

Julien Marrec gravatar image Julien Marrec  ( 2017-02-22 16:45:29 -0500 )edit

Perfect Julien!!

Shawn gravatar image Shawn  ( 2017-02-22 16:47:30 -0500 )edit
1

1) don't use an air loop. use the ZoneHVAC:EnergyRecoveryVentilator object only, and delete the air loop from your model. 2) You need to specify both a heating and cooling thermostat for your zone. If you don't want heating or cooling, just set the thermostat sufficiently high or low (e.g. 0 C for heating and 50 C for cooling). Use a constant temperature for both. 3) A heat recovery ventilator will only exchange heat - it cannot provide heating or cooling. You will need HVAC equipment to provide that, thus the temperature swings.

mdahlhausen gravatar image mdahlhausen  ( 2017-02-22 17:02:50 -0500 )edit
1

the water use equipment error likely existed in your prior model, but you ran into your other error first and the simulation quit before it got to this one. It looks like you might not have a hot water loop that serves hot water to your service hot water loop. You can try adding that or deleting the service hot water for now to get your simulation running.

mdahlhausen gravatar image mdahlhausen  ( 2017-02-23 14:16:05 -0500 )edit

per above, 3) A heat recovery ventilator will only exchange heat - it cannot provide heating or cooling. You will need HVAC equipment to provide that, thus the temperature swings.

mdahlhausen gravatar image mdahlhausen  ( 2017-02-23 17:02:50 -0500 )edit

1 Answer

Sort by » oldest newest most voted
2

answered 2017-02-21 17:01:18 -0500

Can you describe more of what you mean by "it doesn't do anything"?

If you only have a single zone model, you can simulate this with the ZoneHVAC:EnergyRecoveryVentilator object. This is available in the Library under "ERV" in the thermal zones tab in OpenStudio.

Remember to include heating and cooling thermostat schedule objects in your thermal zone.

edit flag offensive delete link more

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account.

Add Answer

 

Question Tools

1 follower

Stats

Asked: 2017-02-20 16:37:37 -0500

Seen: 651 times

Last updated: Feb 23 '17