New system installations: Considerations
Do you want a full system with a thermostat or a specific machine for the summer like a swamp cooler?
Do you need a new furnace just for the winter? For any of these projects, the cost will vary depending on the quality, style and machine size you choose.
If you have a tight budget, think of going smaller and upgrading over time. For example, if you can't afford to convert your entire home to solar power, you may want to consider only utilizing it to heat your water. Some other types of heating systems are:
Single stage or multi-stage? -- Single stage systems have one speed designed to provide maximum comfort. They run at full power even when they don't have to. A multi-stage system adjusts itself as needed to maintain comfort. While more expensive upfront, these systems offer greater savings in the long run.
Zoned systems -- Zoned systems monitor areas of your house and only heat or cool the ones that need it. Dampers in the ducting close off areas of the house to divert the airflow only to certain rooms.
Humidity control -- This is a must-have in very dry or humid climates. Remember humidifiers or dehumidifiers do not work when the system is not on, so you may want to see about a separate humidifying system.
Filtration systems -- A second-stage filter is sometimes inserted & used to remove particulates such as pets, smoking or cooking, as well as other odors, gases, and VOCs (volatile organic compounds). A HEPA filter is also available to remove spores, pollens, bacteria and lung-damaging particles. There are also systems that use ultraviolet (UV) light to protect against bacteria and germs.
Ductwork in your house is one of the main sources of loss of efficiency with your HVAC unit. If you are installing a completely new system, the contractor will have to map out:
Ducts: to ensure that the air is being efficiently circulated throughout your home.
Vents: so they send the air out correctly, and it must be determined if these vents will be in the ceiling or the floor
Floor vents: so that they are not going to be blocked by furniture or other objects.
If you are using existing ducting, it will have to be inspected. Proper ducting loses around 2% to 5% of your energy. Old, leaking ducts can lose 50% or more. A contractor will need to have the ducts inspected and replace any parts ahead of time. If you are changing the size of your HVAC system because of significant changes to your home, you might need to replace the ductwork regardless.
Installing an HVAC system involves determining whether the unit is going to be roof-mounted or a split system.
Roof-mounted systems have the heating and cooling systems in one cabinet. Sometimes called "gas packs" (if the heater uses natural gas), they typically cost less than a comparable split system. In dry regions, most homes originally had "swamp-coolers" installed. When replacing them with HVAC systems, it's often cheaper to use existing mounts and ducting.
They are also often harder to install. A proper location on the roof must be selected that can support the weight of the unit. Then a platform must be built and a drain pipe for the unit must be run along the roof to avoid problems with mold and corrosion. A crane must be used to lift the unit onto the roof while a team guides it into place and hooks it up.
Split HVAC System
Split systems are generally more efficient because the heat exchanger can be put in a shadier or cooler location instead of on the roof in full sunlight. All that is needed for the heat exchanger is a concrete platform in the right spot.
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.