How Big Whole House Generators Are

Whether you have a small cottage or a large home, it’s important to have the proper backup generator. Without electricity, many of your appliances will break down or stop working, making it a dangerous situation during storms or power outages.

One way to determine how big a whole house generator you need is to know how much wattage your appliances use. This wattage is usually on the appliance’s label.


The size of a whole house generator is largely dependent on how much power you need. This will depend on how many appliances you have that use a lot of electricity, the number of central air conditioners in your home, and other factors.

To determine what size generator you need, start by listing all of the appliances and electrical devices that you want to run during an outage. Then, check their owner’s manuals for wattages to determine what running and starting wattage they need.

Generally, starting wattage (also known as surge wattage) is 2-3 times more than running wattage. This means that if you have a refrigerator that states 700 running watts, you’ll need about 2,100 watts to start it up when you need it!


Power outages are inconvenient, costly, and can be dangerous if prolonged. To help protect your home, a generator is a smart investment.

A whole house generator, also known as a standby generator, automatically detects when your utility goes out and comes on to restore power within seconds. They are permanently connected to your electrical panel and are fueled by either natural gas or liquid propane.

They offer many benefits over a portable generator, including bigger engines that are liquid-cooled for longer run times without maintenance, sophisticated programming for better load management, and fuel options like natural gas or liquid propane. They typically come in sizes from 22 to 48kW.


The fuel used for a typical whole house generator can be natural gas, liquid propane, or diesel. These three options differ in availability, cost, efficiency, and environmental impact.

In most cases, natural gas is a convenient option for homeowners as it’s already being used in their homes for heating and cooling, fireplaces, appliances, and other uses. It can be tapped into an existing gas line in the home to feed power to your generator.

Liquid propane (LP) is another option that can be pumped from an underground storage tank or delivered via a service truck. This type of fuel has a longer shelf life than gasoline and does not degrade as quickly.


When you think about how big whole house generators are, it’s easy to get overwhelmed. There are many choices to make, including size, type, fuel, and a myriad of other elements that can impact your final price.

For example, if you have critical medical devices such as a breathing machine, respirator, home dialysis machine, or power-assistive device, you need a whole house generator to keep them going until the electricity comes back on.

Fortunately, most backup generators are designed to comply with noise ordinances so that they won’t bother your neighbors or drive you crazy. The most popular Generac whole house generators are rated at about 66dB when heard from 23 feet away, which is just loud enough to make you feel uncomfortable without annoying your neighbors.


A whole house generator requires regular maintenance and inspections to ensure it’s in good working condition. This helps to keep it ready to provide electricity during a power outage.

The frequency and extent of these maintenance tasks depend on the type and size of your generator. For example, industrial products tend to require more thorough inspections and service than residential generators.

Routine visual inspection includes checking that the unit is clean (even if it is enclosed), no rodents have inhabited it, there are no loose wires or clamps, and everything functions correctly. Other routine maintenance tasks include checking battery electrolyte levels, specific gravity, fuel and oil hoses, air filter changes, spark plugs, and more.