com.hp.devicemodel.TransportProxy

These steps were helpful.

Reset the Printing System:

Note: This will remove all printers in the print and Fax/Scan, any printer removed can be re-added later by clicking the plus ➕ symbol.

1. Click the Apple icon and then click System Preferences.
2. Click Printers & Scanners.
3. Right-click (or Ctrl +click) in the left white side panel, then click Reset Printing System.
4. Click OK to confirm the reset.
5. Type the correct Name and Password.
6. Click OK to reset the printing system.

source: Solved: com.hp.devicemodel.transportproxy uses 100 percent of CPU, p... - HP Support Forum - 5581256

It appears to be a driver for an HP printer/device.

http://h30434.www3.hp.com/t5/Printer-All-in-One-Install-Setup/OS-X-Yosemite-Driv er-for-OJ-8600-Pro-loses-settings/td-p/4…

Try updating/reinstall the drivers for your HP devices.

Also try resetting the SMC since that can help with fan problems:

Intel-based Macs: Resetting the System Management Controller (SMC)

Have you been able to solve the problem? I'm experiencing the exact same at the moment..

Update: solved it by uninstalling the HP software by using the HP uninstaller, ventilation slowed down immediately after completion.

Hi guys,

No need to update/reinstall the drivers for your HP devices. No need to uninstall the HP software by using the HP uninstaller (pre-Yosemite leftover)). Just go to the printers and scanners preference and delete the various entrees of trouble maker printer (the one who initiated the issue) from the list. Immediate solution guaranteed (it may take a few moments for the MacBook to cool down though).

Thanks Pink Panther! My problem solved!

My friend.. problem solved. Thank you very much!

Thanks, that fixed it 🙂

How do you do that exactly? I tried deleting all the HP printer's in the list of my Printer and scanner page but on the activities monitor still shows com.hp.devicemodel.transportproxy

After deleting the printers did you reboot?

yes i did reboot

Nevermind, I checked again and apparently I did not close all of the printers, thank you Pink Panther and lllaass for helping me.

uninstalling the HP 6500 worked for me as well - the HP process was using over 300% CPU!

Oh man, thank you. This issue had been making my Air run like a hot plate for days.

Thanks so much, Pink Panther! Worked perfectly ... almost immediate results!