Problem with EUI and annual loads calculations when changing the fabric's construction set

Hi! I am working on a simple single zone room and trying to test different parameters that mainly concern the fabric construction. I have built the model using Honeybee 1.6 and followed the program of a midrise apartment as an estimation. I have created my own construction details of the fabric with an insulation layer in between. I have made all construction layers fixed apart from the insulation layer where I kept it as a number slider to explore the impact when changing the thickness. I have been trying to simulate the annual heating and cooling loads but I am getting the same EUI and the same heating and cooling loads. The same issue is occurring when I constructed the widow material where changing the u value and the SHGC does not give any different outcomes. I have tried introducing an HVAC system but the same issue still noticeable. I have tried running it on different machines but no change. Any help or suggestion to understand the issue is highly appreciated.

Hi @Kamal_Haddad, welcome to the forum - how much are you changing the thickness by and what is original thickness?

You’ll likely need to increase thickness by around 50mm to see a significant difference.

Also what climate are you working in? Temperate climates you’ll see less impact in, hot and cold climates you’ll likely see a bigger impact.

What system are you applying? Heating/cooling will be impacted by system efficiency so you’ll probably be better using an ideal air system to see the difference

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Hi @charlie.brooker, Thank you for your response. I am working on a hot-arid climate (Jordan). I have been testing the values between 0.01m and 0.1m with a step of 0.01 but getting the exact same results in each run. I have tried it with different parameters like WWR and its working perfectly. As you mentioned, I am using an Ideal Air HVAC system with DCV set to true and Sensible heat recovery and latent heat recovery set to 0.75 while other inputs are set to defaults.

Thanks @Kamal_Haddad.

I would turn off heat recovery and DCV (no economiser).

I would test increments of 50mm instead of 10mm.

Hopefully that helps see a difference.

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Thanks @charlie.brooker this helped a lot. I had an issue with my definition of the specific heat of some fabric layers. Your suggestions have helped getting better results to what I am expecting in my work. Many thanks!

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