Modeling, optimization, control or simulation of building energy systems:
-Analytical or Numerical models.
You may also use building energy simulation tools: eQuest, BEOpt, Energy Plus, ...
-Read several papers of a topic of your interest and learn about the most recent works in that area -You may come up with a new study or choose a peer-reviewed journal paper and replicate it with your own model, results and discussions.
-Geothermal cooling/heating system
-Investigation of passive design options for a particular building
-Solar building technologies: heating and cooling
-Innovative educational tools
-Radiant cooling and heating systems