Power outages disrupt daily life and compromise home systems. For a 1600 square foot house, generator sizing is dictated by the specific appliances and systems the homeowner intends to keep operational during an outage, not the home’s physical dimensions. Assessing these individual power requirements is the first step toward selecting a unit that provides reliable backup power without unnecessary expense.
Determining Your Power Needs
Generator sizing begins with a detailed load assessment, requiring the homeowner to decide between powering only necessary circuits or achieving whole-house comfort. Focusing on essential circuits means prioritizing items that maintain safety and prevent damage, such as the refrigerator, furnace fan, well pump, and a few lights. This approach typically results in a smaller, more economical generator choice, providing functionality rather than convenience.
A comprehensive approach aims for whole-house comfort, including high-draw appliances like central air conditioning, an electric range, or a clothes dryer. To begin the assessment, one must identify the running wattage of each intended appliance. A standard refrigerator typically draws around 600 watts, while a gas furnace fan might require 800 watts to operate. A sump pump, which is often a high priority for flood prevention, can demand approximately 1000 watts of continuous power.
The total power requirement is the sum of the running wattages for all devices operating simultaneously during an outage. For example, if the plan is to run a refrigerator (600W), a furnace fan (800W), and ten 60-watt light bulbs (600W total), the combined running load is 2000 watts. This foundational calculation establishes the minimum continuous power the generator must supply to maintain basic function.
Calculating Required Wattage
Generator sizing must account for the difference between continuous power draw (Running Watts) and the momentary surge needed to start a device (Starting Watts). Running Watts represent the continuous power needed to keep an appliance operating.
Motor-driven appliances, such as refrigerators, well pumps, and air conditioners, require a significant, momentary burst of power to overcome inertia and initiate the motor’s rotation. This Starting Wattage can be two to three times higher than the appliance’s Running Wattage, lasting only a fraction of a second. For instance, a well pump that runs at 1000 watts might require 3000 watts to start up.
To accurately size a generator, calculate the total running wattage of all devices intended for simultaneous use. To this sum, only the single largest starting wattage requirement from any one appliance is added, not the starting wattage of every device. The formula is: (Total Running Watts of all devices) + (Largest Single Appliance Starting Wattage). If the total running load is 5,000 watts and the largest surge comes from a central air conditioner requiring 7,000 starting watts, the generator must be rated for at least 12,000 watts to handle the initial load spike.
This calculation ensures the generator can handle the initial demand when the largest motor-driven appliance cycles on while all other devices are already running. Failing to account for this surge can cause the generator to overload, trip its breaker, or potentially damage the connected appliances.
Sizing Recommendations for a 1600 sq ft Home
Translating the calculated wattage into a generator size for a 1600 square foot home typically falls into three distinct coverage scenarios.
Essential Coverage
This scenario focuses on maintaining basic function and safety, requiring a generator in the 5,000 to 7,500-watt range. This size is generally sufficient to power the refrigerator, furnace, a few lights, and perhaps a television or computer, often utilizing a portable generator connected via a manual transfer switch.
Comfort Coverage
This scenario aims to power all essential items plus one or two high-draw appliances, such as a small central air conditioning unit or an electric water heater. This level of coverage typically requires a generator rated between 10,000 and 15,000 watts. A unit in this range allows for greater flexibility in appliance usage, providing a higher degree of comfort during extended outages.
Whole-House Coverage
This is the most comprehensive option, designed to power nearly every circuit simultaneously, allowing the home to operate almost normally during an outage. For a 1600 square foot home with modern appliances, this level of coverage usually necessitates a generator rated at 18,000 to 22,000 watts or more. Generators of this size are almost always permanent standby units, which automatically activate when utility power is lost.
Choosing the appropriate size depends on the homeowner’s tolerance for inconvenience and budget, as cost increases significantly with wattage capacity. The final selection should align with the specific load assessment calculation to ensure the generator is neither undersized nor unnecessarily large.
Generator Type and Fuel Options
Once the required wattage is determined, the next consideration involves the generator type and fuel source, which impacts operation and cost.
Portable Generators
Portable Generators are typically lower in cost and wattage, often ranging up to 15,000 watts, and require manual setup and refueling. These units commonly run on gasoline or propane, offering flexibility but requiring the user to manage fuel storage and connection during an outage.
Standby Generators
Standby Generators are permanently installed outside the home, connected directly to the electrical system via an automatic transfer switch. These units are generally higher in wattage, often exceeding 18,000 watts, and are designed for hands-off operation. Standby units typically run on natural gas or liquid propane (LP), providing a continuous fuel supply without the need for manual refueling.
Fuel Considerations
Natural gas offers the advantage of an unlimited supply from the utility line, eliminating the need for storage, though its pressure can sometimes drop during widespread emergencies. Propane is easily stored in tanks, providing a reliable, long-shelf-life fuel source, but the supply is limited by the tank size. Gasoline is readily available but degrades over time, making it less suitable for long-term storage and extended outages.