Antihistamines, H1. Histamine antagonists or antihistamines are drugs that relieve allergy symptoms.Histamine is a chemical used to identify and remove substances that trigger an allergic response. Ã¢ There are four histamine receptors &#40;designated H<sub>1</sub>, H<sub>2</sub>, H<sub>3</sub>, H<sub>4</sub>&#41;.
Quick Answer. Blocked condensation drain lines often cause excessive amounts of water in an air conditioner drain pan. These lines are designed to funnel excess water from condensation away from the air conditioning system inside the home. If these lines become blocked, the excess water drains into a drain pan.
Report Abuse. Some air conditioners contain freon, carbon dioxide or ammonia. All are bad for the environment (CO2 isn't as bad as people think it is, people make CO2 when they breathe). But these chemicals stay inside of the air conditioner, these gases are responsible for making it cold.ir conditioners do not normally make a reaction that involves releasing CO2 (except when the fail and burn up, I suppose).