Energy or Qi clashes are similar to formal clashes in some ways, but formal clashes induce bad luck by the form and shape of an object while Qi clashes are caused by the strong aerodynamics due to energy or Qi flow.
Energy or Qi clashes are commonly due to overactive Yang 阳 energy that can be caused by a sharp corner or busy traffic especially if the curve of the road point to your house. Energy or Qi clashes are associated with the movement of Yang 阳 energy in the air hat goes too fast. That’s why a house is said to be in such a clash if the Yang 阳 energy comes rushing in. Since Qi clashes involve airflow, they can be resolved by the method of covering, blocking and pushing away.
Covering (Che 遮)– use a curtain or close the window suffering from the flow of energy.
Blocking (Dang 挡) – use a plant, a stone or water to block the incoming energy.
Pushing away or fight (Dou 斗) – use a convex mirror, a 3-prong fork or an 8-trigram mirror to fight the energy.
However the best is to turn this energy around for your own use. This method is a bit complicated and it requires some basic FengShui knowledge.
If the clash comes from the East which belong to wood as in the five elements, and is Chen 辰 in the 8 trigrams, you can use fire to dissipate the wood energy, or use metal to control the wood energy.
Use fire to produce wood energy so as to bring back the Yin-Yang balance, the energy will be working for you rather than against you. In this resolutions, you have to know exactly the direction of the clash, its nature in the five elements and the 8 trigrams.
Others clashes include formal clashes, construction clashes, smell clashes, brightness clashes, noise clashes, electromagnetic clashes, and color clashes. There is another called as calculation clashes (Li Qi theory). There are two man streams of Li Qi theory. One is the Nine Stars from the Flying Star plan - the Nobility star comes first, the Sickness star comes second, the Arguments star comes third, the Academic star comes fourth, the Mishaps star comes fifth, the Authority star comes sixth and so on. The other stream involves the interior setup. For example, the number of windows, steps and light bulbs should be in odd number for good luck but I personally do not think this calculation is reasonable and I would not recommend using it.