A great contractor can tell if the house has prerequisite duct work throughout the house for superior air movement. A heating system results in that the groundwork has been laid for air. Ducts will breed the HVAC system, create noise, pollute the atmosphere, drain energy, and also cause a hassle even. Placement is also important, as there has to be use of airways without any barriers. Units that are outside should be at least two feet away from any plants or shrubbery that could cause any kind of congestion, hvac quotes.