Inflation layer

Hi, I want to simulate a turbulent air flow through a heating coil. Heres the system:

https://preview.redd.it/g6o8d8xadegf1.png?width=729&format=png&auto=webp&s=7ce691328ede7d47b63752b720c591f043724e5c

https://preview.redd.it/frvwbjjddegf1.png?width=669&format=png&auto=webp&s=3664a19aad980166a2430e3696bff59bd2b70b52

a heat flux density is impressed on the heating coil, therefore I want to use inflation layers on the coil. First of all I used sizing on all faces of the system and a very fine mesh on the coil itself. Now when I try to use inflation layer I use as geometry the coil and for the edge the faces of the coil, my element quality is horrible.

https://preview.redd.it/a0owlo61eegf1.png?width=1552&format=png&auto=webp&s=78c5a78b63e7d7aa727eb599a781dd19fb749d00

https://preview.redd.it/qg5yoso2eegf1.png?width=563&format=png&auto=webp&s=a9ffafb90bdb198eb46e14265812837ecc865b80

https://preview.redd.it/nmcm4j54eegf1.png?width=447&format=png&auto=webp&s=575f258014c41fcc0ad0ae7193979089ae3502cd

Sorry my program is in german.

Is it correct that I use as geometry the solid coil and for the edges the faces of the solid coil or what is the issue? Thanks