As the Tick recommends, there are duties you can do that qualify work. I am in a similar situation, I felt my position being used primarily for drafting and tangential tasks engineering work. Plus I saw other people getting mentored and trained with less experience and education.I'm taking a more proactive approach, and I started building references/qualifying experience in my area. There are things to do, on your own time that will benefit you and your company. I'm not sure if it will work, but I think it will defintely add value in the long term.
1)Make lists for shop drawing review, QC of specifications, co-ordinate details and specifications. Show this to senior staff with PE's for their opinions and corrections. These people will serve as references and this will add to your qualifying experience.
2) Research! Do a code review in an area your company is weak in, in your area. Say mabey smoke control. Review the NFPA and other codes. Review the literature and develop a best practice per occupancy, hazard, etc. Use these researched to improve #1 & in coordination and in Q.C., interfacing systems, and harmozing different standards. Look at the novel. For example NFPA 72 2010 will allow for integration of gas detection and fire alarm, how will this affect mechanical room design? Again have this reviewed by a PE when finished.
3) Develop design tools. Work on some excel or HVAC software for some general designs. Learn how to program controllers, learn how to simulate on HVAC software with trial and free version, etc. Ask questions and show engineers.
4) Get practical. Even consider taking outside tech courses in a community college in HVAC boilers, PLC's & refrigeration. From this enhance your reports and standards from #1.
5)Network internally and externally. Meet PE's outside in ASHRAE chapters. Aks questions share and discuss all the stuff you'll be working on. Yes a lot of this is outside work but you'll be improving yourself and become more efficient. Plublish these mini projects on a pdf and email it as a review to the company, asking for opinions and offer it as a design aide. If its of some really good value, publish it or present it a peer review or white paper. Offer to do it with a senior member. Your company can use this for marketing.
6)Keep a notebook of all your references and developed material. You'll soon be "off the drafting table" and doing more design, commissioning, and engineering. Remember to be humble and ask questions, don't give the impression you're going to cross company lines. Plus you'll have a list of projects that will add value to your company, make you a better engineer, and give you qualifying experience.