Look at any case. Label the sides
1 for the shortest,
3 for the longest and
2 for the other side.
For the Q100 that would be as follows:
Note that on the front, the drive ejects on the right hand side of the front panel. I marked this on the overhead view so you can identify the front width as being side 2 and the case being side 3 in depth.
As the Q100 has dimensions of 450*140*360 mm you can easily work out what side relates to what dimension.
450(Side 3)*140(Side 1)*360(Side 2) mm
Think about how the case sits and you'll see that Side 1 and Side 2 will be the front dimensions and Side 3 will be the depth of the case.
14cm height (Side 1) is less than the 18cm space between shelves - it fits! Next the width, at 36cm (Side 2) it will easily fit in the 45cm wide gap. The big question is the depth - your TV unit does not look very deep and the case is 45cm deep (Side 3).
Now consider the Zalman Z1 case. Using the same labelling method for the sides you get:
The dimensions of that case are listed as 169*425*340 mm so you can easily work out what side relates to what dimension
169(Side 1) * 425(Side 3) x 340(Side 2) mm
Think about how the case will sit on its side and you'll see that Side 1 and Side 3 will be the front dimensions and Side 2 will be the depth of the case.
169mm height (Side 1) is less than the 180mm space between shelves - it fits! Next the width, at 425mm (Side 3) it will just squeeze in the 450mm wide gap. This case isn't as deep at just 340mm (Side 2) so if your shelf is 340mm or more deep it will fit.