Buyer’s Guide for Whole Home Generators

Several years ago, a standby generator was considered an expensive luxury. After our region experienced a number of widespread, severe weather events with power outages that lasted for weeks, generators are now considered a necessary emergency planning tool. A whole home generator can make your home a safe and comfortable refuge, even in scenes of chaos and disaster.

Generators are available in two major types: small, portable standby generators and larger, Whole Home Generators.

• Portable generators can be stored safely away until needed. During a power outage, the generator is set up (outdoors) and started. It can either be wired directly into the electrical panel or used with several extension cords. Portable generators will not generate sufficient electricity to power all of the circuits in your home; if wired direct, a limited number of circuits can be powered. Make sure that you are prepared with the fuel necessary to power the generator for a few days.
• Whole Home Generators have a wide range of capacity, from 22kW to 48kW, enough to power the entire house and make you forget the power outage. They are designed to engage within seconds after losing power and are installed permanently outdoors with a ready fuel supply. The liquid-cooled engine runs much quieter than portable generators.

If you have determined that a Whole Home Generator best meets your family’s needs, here are three steps to help you decide which model best fits your situation.

First Step: Determine Which Fuel is Available. Many portable generators are fueled by propane bottles or gasoline and the small fuel tanks needed to be refilled often. Whole house generators offer a few different fuels—fuel choices are propane, natural gas, and diesel fuel. You will need to make sure the fuel of your choice is available locally and can be used on your property.

• Both liquid propane and diesel fuel will require a large tank on-site to fuel the generator properly
• If natural gas is available at your home, it will require a properly sized supply line and meter to accommodate the generator.
• Your installation contractor can help you explore this option.

Second Step: Determine the Right Size Whole Home Generator. If your goal is to power your home as if the power grid was still delivering power, how much power will be needed? This question might prove difficult; consider consulting your electrician. Whole Home Generator are sized by kW (1000 watts). To determine the need, you might:

• Gather manufacturer’s data plate information on major appliances—both the starting amps and the voltage required for the appliances. Multiply the amps by the volts to determine watts—amps x volts = watts.
• Gather the same information from your electrical service panel. If your home service panel receives 100 amps, with 240 volts available for large appliances, such as the dryer, a quick calculation shows 100 amps x 240 volts = 24,000 watts. Divide this number by 1,000 to determine kW—your home receives 24kW. This is a method to determine a guideline for a conversation with your electrician.
• In order to handle peak loads under difficult situations, your electrician will recommend adding 25% to the calculated load. In the above example, 24 kW x 25% = 30 kW. This is a reasonable discussion point, but the decision is yours.
• Selecting the correct whole-house generator by kW:
  • An entry-level whole-house generator might be the minimum size—a 22 kW generator.
  • A mid-range whole-house generator is sized between 27 kW and 36 kW and accounts for the lion-share of generator sales. Expect some advanced features with these sizes, such as load-managing hardware that mitigate the load surge when the air conditioner cycle begins.
  • Whole-house generators for large homes are between 38 kW and 48 kW, capable of handling the power needs of the largest of homes.

Third Step: Determine the Appropriate Transfer Switch. Being prepared for a power outage emergency is great planning. Generating electricity on your property is a tremendous step toward keeping your family safe. What your generator CAN NOT do is send power to the utility grid that can endanger other homes or repairmen working on downed lines.

A transfer switch “unplugs” your home from the utility grid to ensure power generated for your home does not migrate off of your property.

• An automatic transfer switch continuously monitors the utility power grid and detects a power outage that lasts more than a few seconds. The switch simultaneously disconnects the home from the utility grid and starts the generator engine to send power to your home. It will also sense the moment electricity begins to flow through the power lines and reverses the process—stops the engine and plugs the house back onto the power grid.
• The transfer switch will need to be matched to the amp service—a 200-amp electrical service will need a 200 amp transfer switch.

The purchase and installation of a Whole Home Generator is an exciting enhancement, fully appreciated the first time it is utilized. Choose a local contractor, familiar with municipal installation codes, available fuel sources, and a working relationship with the local utility service provider.

Interested in a Whole Home Generator Before Hurricane Season?

Our four decades of experience as a Houston Electrician and contractor AirPro Houston provides you with the skill and expertise to help with Whole Home Generator Installation in your home and business.

We have financing options available with great options with up to 72-month terms with approved credit. Call us today at  281-880-8805 and let us partner with you for all of your electrical repair and installation needs.