A:Answer Hi Barb. Thanks for reaching out! The only models that are compatible to be stacked with the washer that you've offered are: GFT14, GFD14, QFT15, and QFD15. The stacking kit, should you purchase any of those dryers, is GFA24KITL. For venting, page 4 of the installation instructions cover exhaust length. 4" diameter ducting is what is recommended to ensure that the unit is able to vent properly. This information can also be found on page 1 of your installation instructions. We hope that this helps! Stay safe.