The letters in HVAC stand for heating, ventilation and air conditioning. An HVAC system enables you to regulate your home or building’s internal temperature (thermal control) for comfortable living and working. You can bring heat levels down in the summer and up in the winter, keeping your home or office livable year-round. HVAC systems can also help with humidity levels and regulate indoor air quality in a home or office. There are many types of HVAC systems and technologies available.
A BTU is the amount of energy required to heat or cool one pound of water by one degree Fahrenheit. So a 1-ton air conditioner can cool 12,000 pounds of water by one degree every hour. That’s all it means, so don’t let yourself be lost in jargon! How this affects your HVAC installation cost is that the larger your house is, the more tons will be required to heat and cool it.
Installing a split system may involve making modifications to the house itself for the necessary lines to be run. The heat exchangers are also more prone to picking up debris and must be cleaned on a regular basis. While they come with protective screens over the fan, care must still be taken to ensure that nothing gets in, especially in a home with children.
Energy efficiency can be improved even more in central heating systems by introducing zoned heating. This allows a more granular application of heat, similar to non-central heating systems. Zones are controlled by multiple thermostats. In water heating systems the thermostats control zone valves, and in forced air systems they control zone dampers inside the vents which selectively block the flow of air. In this case, the control system is very critical to maintaining a proper temperature.
Though this installation is not always complicated, it's best to work with an air conditioning contractor to ensure it's done correctly. Permits are usually required for this type of work and can be obtained by a state-licensed contractor. You should not attempt to install central air conditioning on your own since you need a license to handle the refrigerant chemicals (Freon) involved.
An alternative to packaged systems is the use of separate indoor and outdoor coils in split systems. Split systems are preferred and widely used worldwide except in North America. In North America, split systems are most often seen in residential applications, but they are gaining popularity in small commercial buildings. The split systems are a great choice for small buildings where ductwork is not feasible or where the space conditioning efficiency is of prime concern . The benefits of ductless air conditioning systems include easy installation, no ductwork, greater zonal control, flexibility of control and quiet operation . In space conditioning, the duct losses can account for 30% of energy consumption . The use of minisplit can result in energy savings in space conditioning as there are no losses associated with ducting.
American design standards are legislated in the Uniform Mechanical Code or International Mechanical Code. In certain states, counties, or cities, either of these codes may be adopted and amended via various legislative processes. These codes are updated and published by the International Association of Plumbing and Mechanical Officials (IAPMO) or the International Code Council (ICC) respectively, on a 3-year code development cycle. Typically, local building permit departments are charged with enforcement of these standards on private and certain public properties.
Reinstall the access panel and disconnect block. Turn on the circuit breaker and furnace switch. Then set the thermostat to a lower temperature and wait for the AC to start (see “Be Patient at Startup,” below). The compressor should run and the condenser fan should spin. If the compressor starts but the fan doesn't, the fan motor is most likely shot. Shut off the power and remove the screws around the condenser cover. Lift the cover and remove the fan blade and motor (Photo 7). Reinstall the blade and secure the cover. Then repower the unit and see if the fan starts. If it doesn't, you've given it your best shot—it's time to call a pro.