Homeowner eyes a 14,500-watt generator, but it delivers 8,750 running watts on natural gas

A homeowner looking to upgrade their backup generator encountered a costly distinction between a generator's advertised rating and its power source.

Here's what to know

In a Reddit post in r/Generator, the homeowner described their existing Wen DF1100T generator and plans to switch to a tri-fuel model. They wanted to use utility natural gas as the primary fuel along with gasoline and propane as backups.

Starting the two air conditioners could briefly push demand above even the homeowner's highest recorded 15-minute average. Their highest recorded summer electricity consumption was 2.15 kilowatt-hours over 15 minutes, amounting to an average demand of 8,600 watts.

The model under consideration was the Wen TF14500X. But according to one commenter, while it's advertised at 14,500 watts, it's rated for just 8,750 running watts when fueled by natural gas.

"The 14500 is likely surge and gasoline; you are going to likely be getting less on natural gas," another commenter explained.

More background

Power spikes, especially during air-conditioner startups, were the homeowner's main concern; they had never connected their existing generator to the entire house.

According to the homeowner, the larger air conditioner was about 18 years old. The outdoor units' nameplates could help clarify startup requirements, a commenter said, pointing to compressor model numbers and locked-rotor amperage.

A commenter urged the homeowner to leave the carbon monoxide monitor intact. They should also follow manufacturer guidance and local placement rules and check whether exhaust could travel. The homeowner planned to put the generator in a vented enclosure against the house and was considering disabling its carbon monoxide cutoff.

What can be done?

Commenters put air-conditioner soft starters on the homeowner's research list ahead of a generator purchase.

Several restarts would give a soft starter time to learn the system's characteristics, one commenter noted. They recommended using an inrush-reading clamp meter to compare startup current before and after installation.

Deciding what needed to operate together during an outage would require a record of the loads from both air conditioners, HVAC blowers, and other major appliances, the commenter advised.

The homeowner said they were willing to avoid running both cooling systems simultaneously.

Where can I learn more?

Other homeowners shopping for backup generators have also had to work out how advertised wattage translates to usable power.

• An owner's 13,000-watt tri-fuel generator powered AC, stove, and pump, but not heat.

• A homeowner sizing backup power for a three-to-four-bedroom house heard recommendations for smaller generators from outage veterans.

• A homeowner received a 9,600-watt generator recommendation, but commenters warned about high fuel consumption.

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