How Does a Whole House Generator Work?

how does whole house generator work

A whole house generator is a stationary fixture that connects to your home electrical system and fuel source (natural gas or propane). It automatically starts when power goes out, powering up your furnace, kitchen appliances, lights, and even well pump.

They can also help you avoid the chaos of power outages, including the loss of food or the threat of spoilage. A generator can save you money, improve your home value, and add a sense of security.

Automatic Transfer Switch

An automatic transfer switch, or ATS, is an electronic device that monitors electrical signals from your primary power source and backup generator to transfer your loads to the alternative power supply. It uses a microprocessor to continuously track electrical parameters like voltage and frequency, as well as the status of your connected devices.

When a power outage occurs, your automatic transfer switch senses it and directs the generator to start. Then, a set of relays transfers your building’s loads from the utility grid to the generator.

Depending on the quality of your generator, and the type of automatic transfer switch, this process can take only seconds or minutes. Some systems even deliver uninterrupted power.

For homes with older, less reliable service, a standby generator installation may be integrated into an electrical upgrade. This can reduce future costs because the electrician won’t have to tear up your current wiring to install a new switch.

Built-In Exhaust System

A generator’s exhaust system is an essential part of its operation. As thousands of small explosions occur in the engine, they produce gases that need to be safely disposed of.

These are carbon dioxide, nitrogen oxides, and hydrocarbons that pose health risks to homeowners when inhaled. Whole house generators feature a built-in exhaust system that routes these gases outside your home.

In addition, a generator can be located far from your home, ensuring it will not send carbon monoxide into your house through open windows, doors, or vents. This is important for safety and code compliance.

The built-in exhaust system on a whole house generator is similar to the one in a car. It is designed to safely dispose of the exhaust gas and other chemicals that are released by your generator.

Liquid-Cooled Engines

Liquid cooled engines use water instead of air to cool the engine. This allows the engine to work for a longer period of time and run at higher compression.

It also helps keep the engine’s temperature within manageable limits. This is crucial for a generator because if one part overheats, the whole unit can fail.

The liquid is also denser than air, meaning more heat can be packaged around a hot spot, allowing the engine to operate at a much lower temperature. This, in turn, allows the engine to run with better tolerances and produces more power.

Because of these advantages, liquid cooled engines are ideal for commercial establishments. They can fulfill huge energy requirements, especially during power outages. However, they can be quite expensive and require a lot of maintenance. In addition, they require a lot of space and are heavy to move around. An air cooled generator, on the other hand, is smaller and lighter in weight, making it easier to move.


The installation process for a whole house generator involves a lot of different steps, from setting up the location to obtaining permits. This is a project best left to a professional.

A licensed electrician should be hired to handle this portion of the installation. They should know the local codes, how to secure the required permits, and be familiar with your home’s electrical system.

They should also be familiar with the construction types in your area, the quality of local utility power, and how to size a generator for your needs.

When determining how much power your generator needs, make sure to account for the largest load in your home, such as the heat and air conditioning. You can reduce the size of your unit by not connecting appliances that you rarely use, such as the dishwasher and dryer.

After choosing a model and sizing it for your needs, the installer will install it. This includes securing the unit, placing it on a pad, and installing the automatic transfer switch.