Generator Sizing & Load Calculation

The #1 Cause of Generator Disappointment Is Wrong Sizing

Buying a generator is a major investment - and the single biggest mistake homeowners make is buying a unit that is too small for what they actually want to power. The second biggest mistake is over-buying and paying for capacity you will never use. ARK Generators helps Greater Houston Area homeowners and business owners avoid both by doing real load calculations before you sign anything. This page walks through how we size generators and what you should know before shopping.

What Load Calculation Actually Means

A load calculation is the process of measuring exactly how much electrical demand your home or business actually has - taking into account:

• Starting vs. running watts - Motors, compressors, and well pumps pull significantly more power at startup than during steady operation
• HVAC demand - Air conditioning is usually the largest single load in a Houston home
• Critical vs. optional circuits - What do you must have running during an outage versus what would be nice to have?
• Simultaneous demand - If you want to run AC, refrigerator, lighting, and a well pump at the same time, your generator needs to handle that peak - not just the sum of average draws
• Future load growth - Are you adding an EV charger? A pool? A backup freezer? We plan for that

Why "Square Feet" Rules of Thumb Are Wrong

Many generator sellers will quote you a unit based on square footage alone - "your home is 3,000 sqft, you need a 22kW generator." That is a lazy calculation. A 3,000 sqft home with a big AC, a well pump, an electric range, and an EV charger has a very different load profile than a 3,000 sqft home with gas appliances and no well. We walk your home, look at your panel, and ask real questions before we quote.

Generator Placement and Gas Supply

Sizing is only half the story. Placement and fuel supply matter just as much. During a planning visit, we also check:

• Gas meter capacity - Most standby generators need a meter upgrade to supply sufficient fuel pressure. The volume of fuel is the most important factor for engine longevity. ARK includes the meter upgrade with every project.
• Required setback distances - Generators must be placed a specific distance from windows, doors, fresh air intakes and combustibles per NFPA 37 and local code. Hurricane Beryl provided an education for everyone in Houston. CO2 poisoning is real and lead to death. ARK takes placement serious.
• Sound considerations - Distance from bedrooms and neighboring property lines
• Flood and storm exposure - Elevation and protection from falling branches and debris
• Concrete pad requirements - Proper foundation that will not shift or erode
• Electrical service tie-in path - Where the conduit will run and how it terminates at your panel

The Meter Upgrade No One Tells You About

Here is a frustrating surprise we have seen countless times: a homeowner buys a standby generator only to find out their existing gas meter cannot supply enough fuel. Every install we do checks gas meter capacity first - and if an upgrade is needed, we coordinate with Centerpoint Energy (or your local utility) before installation day. You should never find out about a meter upgrade after the concrete pad is poured. The meter upgrade is the cheapest form of insurance for the life expectancy of your engine. NOTE: Centerpoint Gas Energy will not upgrade your gas meter before the generator is set in place. THIS IS GREAT STUFF GUYS!!

Start With a Free Planning Visit

Whether you are exploring your options for the first time, learning about the Generac and Kohler lineups, or trying to figure out what the previous contractor meant, we will come out, walk the property, and give you an honest recommendation. Request a free planning visit or call (936) 441-4ARK. See also our residential installation and commercial installation pages for what happens after the plan is set.