Full disclosure, this is a silly question. You may elect not to take it seriously.
Warforged have the following traits worth of note:
You have advantage on saving throws against being poisoned, and you have resistance to poison damage.
You don't need to eat, drink, or breathe.
Although they do not need to breathe, it is somewhat unclear as to whether they can (whether they have lungs). Perhaps so, due to being able to speak (unless their vocal chords don't require the passage of air to function); perhaps not, due to the fact they are only resistant to poison, and we know that the Last War in Eberron involved a lot of deadly gases being used, leading to believe that perhaps Warforged have been conceived specifically without a breathing function in order not to die from gases.
Now, Ventilating Lungs have the following features worth of note:
When you attune to these lungs, they replace the lungs in your chest, which disappear.
If your attunement to the lungs ends, your original lungs reappear.
If Warforged do, in fact, have lungs, then everything works as per normal. But if Warforged don't have lungs, and one of them somehow decides to attune to Ventilating Lungs, what happens? And then, what happens if they deattune?
It is somewhat humorous, in this situation, to imagine a lungless Warforged, attuning then deattuning to the magic item, and suddenly getting a pair of real lungs from nowhere! Although in reality, that's probably not how it works.