The seller collects up front for a system an uneducated buyer (the homeowner) has chosen according to very limited and, quite possibly, faulty criteria. In most cases, the companies that are offering the ability to order a system online use the system that is currently in the home to determine which new system is the correct fit. This is not a good idea - and here's why:
According to a statement posted by Energy Star
... "...nearly half of all HVAC systems are incorrectly installed." Additional studies
by industry professionals state that the majority of systems are not installed correctly. They state the following:
- 72% of installed systems are improperly sized
- 68% of AC Systems were not charged correctly
- 70% of new systems installed do not have proper airflow to support system performance
- 91% did not get tested for combustion safety and efficiency
Judging from my experience in Mesa, AZ and the surrounding areas we serve... it is quite common to find improperly sized equipment in homes (over- or under-sized).
Selecting a new heating and air conditioning system based on the capacity of your existing equipment is not a good idea. If your existing system needs to be replaced - because it failed, your utility costs are high, or it is inefficient and doesn't keep your home comfortable, having an over- or under-sized unit is likely the culprit!
There are good reasons heating and cooling manufacturers have traditionally opposed or forbidden selling equipment direct to the end user, online or otherwise.
There is liability, but also the dynamics of heating and cooling mechanics and efficiency are complex, especially with today's systems. Complications can range from being outright dangerous to higher than expected operating costs, failures, and reduced equipment life. For all of the reasons mentioned, manufacturers require that installation of their equipment be done by a licensed contractor in order to validate the warranty on new equipment. The online process requires this and offers you a couple choices, however, the quality of work done by licensed contractors runs the gamut.