360-499-6604 Generator sizing is one of the most common and confusing questions homeowners face when planning for power outages. Whole-home generators are highly useful tools for backup power planning, but it’s essential to get the right size for your needs.
Generator size depends on usage needs, and not just the size of your home. This home generator sizing guide will share how to choose the right fit for your home. We’ll explain why proper generator sizing matters and how to conduct power load calculation before making a decision.
Why Generator Size Matters for Home Backup Power
In outage prone areas, whole-home generators can be lifesavers. They provide reliable backup power to ensure your family stays safe. Choosing the correct generator size is important for safety, comfort, and usability.
For one thing, the size of a generator determines how much power it can deliver. If your generator is too small for your power needs, it will quickly get overloaded. Strain from overloading causes risk of failure and shortens the unit’s lifespan. If your generator is too powerful for your needs, you’ll waste money on purchase, installation, and maintenance costs.
That’s why it’s so important to calculate your power needs during an outage. You’ll want to calculate your power demand by adding your essential loads, or the systems and appliances you can’t live without.
Understanding Watts, Kilowatts, and Power Demand
When purchasing a new whole-home generator, you must understand the sizing terminology. First, let’s discuss watts. There are two types of watts to consider: running watts and starting watts.
- Running watts: The amount of power it takes to run an appliance continuously once it’s on.
- Starting watts: The amount of power it takes to start an appliance. This typically is a momentary surge to kickstart the motor and can be much higher than running wattage.
It’s important to consider both running and starting watts to prevent tripped breakers. Your generator must be able to handle the power needed to start appliances and run them simultaneously.
A kilowatt (kW) represents 1,000 watts. So, when calculating your total power demand, it can be easier to convert the sum to kilowatts. Many whole-home generators range from 10kW to 30kW depending on their size.
Different homes will have different power demands. To determine the power rating you’ll need, make a list of all the essential loads and their staring and running wattages. Then add a 20%-30% safety buffer on top.
Common Household Items Homeowners Want to Power
The essential loads are the common household items homeowners want to power during outages. This may vary from home to home, but in general, many homeowners will prioritize powering:
- Refrigerators and freezers: Keeping your refrigerator and freezer running ensures you have safe food to eat and avoid food spoilage.
- Heating or cooling systems: Your HVAC system is important for safety, especially during severe weather.
- Sump pumps: Powering your sump pump is essential to prevent flooding, reduce damage, and protect your foundation.
- Lighting and outlets: Lighting and outlets are essential for being able to walk around safely in your home.
- Medical or essential devices: If you have critical medical devices such ventilators, CPAPs, or home dialysis machines, you’ll want to ensure they can remain powered during outages.
Portable Generators vs. Whole-Home Generators
You may be considering whether you should get a portable or whole-home generator. The two tools are both great options for homeowners looking for reliable backup power solutions.
Portable generators are designed for temporary, on-demand power. These units are set in place and started by the user once an outage occurs. They are manually connected to appliances or circuits to power critical appliances. They are not designed to power an entire home. Portable generators require manual setup and shutdown, and users choose which devices to power.
Whole-home generators are permanently installed and built for automatic, long-duration backup power. They sense when the power has gone out and use an automatic transfer switch to start the flow of electricity to your home. They aim to replicate normal household power and can power most or all household items simultaneously without user intervention.
Factors That Influence Generator Size Selection
Outage frequency, climate, household needs, and lifestyle all affect generator sizing decisions. For example, if your area experiences frequent outages and you have high essential load needs, a whole-home generator may be best. If you don’t experience outages frequently but would like to power a few select appliances, a portable generator will likely meet your needs.
If you work from home, you may also benefit from a whole-home generator to keep your business up and running, even during power outages. The size of your home matters when choosing a generator, but your lifestyle and household needs matter even more. For families with small children or the elderly, power needs may be more important.
The size of your generator is a personal and situational choice based on your needs. A professional generator technician can help guide you in making the best decision.
Preparing for a Generator Evaluation
Before speaking with a professional generator technician, gather some basic information, such as listing essential appliances and understanding your outage goals. Generator education should come first, then evaluation by a professional.
If you need help choosing a generator for your home, contact G & G Heating at 360-646-2170 today! We install home generators throughout Olympia, DuPont, Puyallup, Tumwater, and other cities in Washington.
