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Large fish tank in OpenStudio

asked 2016-01-27 13:55:23 -0500

RChidwick gravatar image

updated 2016-02-03 17:35:51 -0500


I am trying to model a large fish tank (essentially a swimming pool - the size of these cylindrical tanks is 3m in diameter, and 2m high) in OpenStudio. I have several thoughts on how I could go about doing this and wanted to get some feedback from the community. Maybe some of you have better ideas. The goal is to account for every way in which the fish tank, in the real world, absorbs and releases thermal energy into the thermal zone, and account for the heating and cooling needs of that water as well.

1) Use the 'Thermal Storage: Chilled Water: Mixed' object. I could use this object in combination with a chilled water radiant floor or some other method of allowing the water to gain and lose energy to the thermal zone, and then use a chiller to cool the water. This idea would cover the thermal storage aspect of the fish tank, but not how the fish tank is actually open the air.

2) Create a 'Water Use Equipment Definition'. A flow rate can be described, along with sensible and latent heat fraction schedules, and a temperature schedule, but no volume.

3) Use the 'Internal Mass' object. I could define the internal mass using material definitions and constructions. This would indirectly be modelling the water's thermal mass properties, but I can no longer actively cool the water, which is an important part of my energy model.

The fish tank is located inside a thermal zone with no windows, just solid walls. The space is also conditioned (currently I just have a PRAC in that zone).

I look forward to hearing your thoughts or other suggestions.

Thank you.

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I don't have an answer but was glad to see you tagged it with swimming-pool, as I think this is large enough that it would be modeled much like swimming pool, vs, a 30-100 gallon tank, which would probably take a similar approach. Assume the fish tank is heated, but not cooled?

David Goldwasser gravatar image David Goldwasser  ( 2016-01-29 11:37:49 -0500 )edit

I visited the Ripley's Aquarium here in Toronto. The one thing I notices was the number and size of pumps required to keep the water circulating, clean and aerated. Huge kWh load.

Chris Jones gravatar image Chris Jones  ( 2016-01-29 12:24:56 -0500 )edit

Thank you both for your comments. David - the tank would be both heated and cooled. The fish require the temperature to be nearly constant if they are to grow large and be healthy. I think the fish can tolerate at most a +/- 2C change, but any more than that and they get stressed and stop growing. But if the tanks are in a well insulated building, and the building is conditioned to below the water temperature, then I suppose the water would only require heating.

RChidwick gravatar image RChidwick  ( 2016-01-29 13:18:09 -0500 )edit

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answered 2016-02-03 16:42:37 -0500

I think the EnergyPlus SwimmingPool:Indoor would probably be the best approach it does the evaporation and heat transfer as well as being connected to a EnergyPlus branch. You might want to look at the documentation:

And the EnergyPlus example file named:


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Thank you for this answer! It is very helpful. I have put together a simulation using the SwimmingPool:Indoor object, but I cannot seem to get any heating to the pool. I compared my simulation to the example file and made sure all the branches were set to active or passive as I saw in the example file. Do you have any ideas as to what could lead to a pool getting no heating? The example file pool is kept at 27, but the fish require a much cooler temperature, around 15C. Could that be the problem?

RChidwick gravatar image RChidwick  ( 2016-02-12 13:35:33 -0500 )edit

Yes, at 15C, they are unlikely to need any heat

JasonGlazer gravatar image JasonGlazer  ( 2016-02-16 08:33:06 -0500 )edit

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Asked: 2016-01-27 13:55:23 -0500

Seen: 714 times

Last updated: Feb 03 '16