How to Install a Home HVAC Unit
Installing a two zone home heating, ventilating and air-conditioning (HVAC) system is not for a casual do-it-yourselfer but most aspects of the system past design, sizing and assembling the unit can be accomplished. The big thing to remember is that in the HVAC world, very little is standard and rules get broken all the time.
Required Materials
- Heater
- 5 wire cable
- 18 gauge wire-for runs over 100ft.
- Thermostat
- Zone controller
- Dampers
Required Tools
- Screws
- Drill with bits
- Stud finder
- Wire pull
- Wire stripper
Step One: Choosing a Thermostat
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Choosing a thermostat is one of the more difficult aspects of installing a home HVAC unit. There are many available units on the market today with all offering differing options. As the HVAC unit that you decide to install becomes more complex, the thermostat needed will change. In most instances, they will become more sophisticated.
In some cases, however, they will become less sophisticated. As stated, there is always an exception to the rule when HVAC systems and installations are concerned. For our two-zone system, a simple thermostat with a call for heat function is desirable. It has two settings; heat or no heat and cool or no cooling.
Step Two: Placing the Thermostat
Placing a thermostat just makes sense when you stop to think about it. It should be placed at about 5' high and in a location that has good airflow. The area should also be used quite a bit. It should not be in a location that receives direct sun, behind a door, on an outside wall, close to a vent or near electrical systems.
Step Three: Choosing Zones
Most home HVAC zones are chosen by floor. They can, however, be chosen in any way you choose. A good idea, however, is to not choose a section of the house to zone that is rarely used or is fairly small. From a cost benefit point of view it is not effective. Also, remember that zones are usually designed towards the furnace for ease of installation.
This does not mean that you cannot have the design call for a break-off to a zone further away from the heat source. A damper, which controls where the heat flow goes, occurs at the break-off point between the main ducting and the airflow to a particular zone. The real need here is to have a conversation with a professional HVAC designer regarding zones and overall ducting size.
Step Four: Installing the Thermostat and Controller
Using a simple thermostat (or a more complex if you so choose) find the stud in the location you choose. In addition to the above conditions it should be located in such a place where running the cable through the wall meets no inner wall obstacles. Drill a hole in the wall and sill and use the wire pull to pull the wire to the HVAC unit. The HVAC cable has a specific color coding method for the wiring, so be sure of which wire goes where.
Attach the damper controller to a wall somewhere near the HVAC unit. Run cable to the HVAC unit and the thermostats in both zones.
Step Five: Have Your Work Checked
The process of hooking up a two-zone home HVAC unit is not very difficult if you understand the unique way that HVAC contractors have oriented their wire coloring system. It should be done carefully to prevent any possibility of harm.
