Air conditioning has as much influence on human health as any generic heating system. Poorly maintained air-conditioning systems (especially large, centralized systems) can occasionally promote the growth and spread of microorganisms such as ''[[Legionella pneumophila]],'' the infectious agent responsible for [[Legionnaire's disease]].<ref>[http://www.merck.com/mrkshared/mmanual/section6/chapter75/75e.jsp Sick building syndrome]</ref> Air conditioning can have a positive effect on sufferers of [[allergy|allergies]] and [[asthma]].<ref>{{Cite web |url=http://www.lungusa.org/site/pp.asp?c=dvLUK9O0E&b=22591 |title=Home Control of Asthma & Allergies |access-date=2007-06-30 |archive-date=2009-06-18 |archive-url=https://web.archive.org/web/20090618051853/http://www.lungusa.org/site/pp.asp?c=dvLUK9O0E&b=22591 |url-status=dead }}</ref> | Air conditioning has as much influence on human health as any generic heating system. Poorly maintained air-conditioning systems (especially large, centralized systems) can occasionally promote the growth and spread of microorganisms such as ''[[Legionella pneumophila]],'' the infectious agent responsible for [[Legionnaire's disease]].<ref>[http://www.merck.com/mrkshared/mmanual/section6/chapter75/75e.jsp Sick building syndrome]</ref> Air conditioning can have a positive effect on sufferers of [[allergy|allergies]] and [[asthma]].<ref>{{Cite web |url=http://www.lungusa.org/site/pp.asp?c=dvLUK9O0E&b=22591 |title=Home Control of Asthma & Allergies |access-date=2007-06-30 |archive-date=2009-06-18 |archive-url=https://web.archive.org/web/20090618051853/http://www.lungusa.org/site/pp.asp?c=dvLUK9O0E&b=22591 |url-status=dead }}</ref> |