# Zone Boundaries

Hello Everyone!

I’m building my own algorithm to use Honeybee + Ladybug Tools for the purpose of Building Characteristic according to Polish Norm of evaluating demand of energy for designed building. We’re starting from twin house building and I have a couple of questions about setting HB Zones and Construction Materials.
I went through all @chris basic tutorial on YT - thanks for the great work! But I have couple of questions how to properly set up the simulation:

1. HB Zone walls have no thicknesses - these are included in Construction Material. How to properly place borders of walls, floor, roof / ceiling? Should I place walls on the inside surface of the building external wall? Internal borders (between zones) in the middel of internal walls?
What about floors? Does floor thuckness should belong to the zone under of above?

2. For the twin house simulation - how should I build and set up zones to have a proper simulation only for one half of the building? The separating wall between halves is fireproof and quite wide - 60cm.

I hope you will find this topic interesting! I will have more topics with my work beginning with
“Building Energy Performance /” in title. Can anyone help me with this?

The thickness of consructions is defined in the material defiinition and not in the geometry.
For energy simulations mostly the ouside boundery is used. (see image below)

For a twin house you could make a model of whole building and and split the simulation in 2 streams.
One for the left and one for the right house. If the neighbors are not at home and have set their thermostat to 10 C the other house has still to be confortable during winter. So you have to define different heating setpoints and a two seperated climate systems for the two houses.
Energyplus has olso the ability to use “The otherside coefficients” for constructions
https://bigladdersoftware.com/epx/docs/8-2/tips-and-tricks-using-energyplus/using-osc-other-side-coefficients-to-create-controlled-panels.html
but as far as I know this not possible yet in honeybee.

@Erikbeeren 's answer is correct. I just wanted to clarify that OUTDOOR surfaces get modeled to the exterior boundary but adjacent INDOOR surfaces should get modeled to the center-line of the interior surface. So interior adjacent surfaces should always bet touching each other.

If I were building this model and both halves of the house have the same occupancy, I would use an Adiabatic boundary condition for the wall in between the two houses (assuming no heat flow and that the temperature of each of the house-halves is the same). If the two halves have wildly different occupancy, then I would probably just simulate everything as one model. Honeybee Legacy does not have support for Other Side Coefficients but the new Honeybee[+] that is in development will support them. So Erik’s suggestion will be possible soon.

1 Like

Hi @chris
That is really great to hear!

Hi!
@Erikbeeren , @chris thank you guys for explanation!
I’m working on it now, setting up the materials and give some updates soon!

Hi guys!
I’m stuck. Is there any way to add a heating system - which is concrete slab with water heating? (See attachment) and calculate heat distribution? This is a very typical solution in our country - apears almost in every project. Standard is water but also: air and electrical system. Any tips?

You can use the Honeybee legacy in combination with this example wich explaines how to set up an internal source construction:

With the new LBT tools I think you will have to use Ironbug. Radiant floors are not yet there as a standard HVAC template.
1 Like