For an oil furnace, a generator size of 5000-7000 watts is usually sufficient. Ensure it can handle the furnace’s startup surge, typically 2-3 times the running wattage.
Oil Furnace Generator Size Chart
Furnace Size (BTU/hr) | Running Wattage (Watts) | Starting Surge Wattage (Watts) | Recommended Generator Size (Watts) |
---|---|---|---|
50,000 – 90,000 | 800 – 1,400 | 2,400 – 4,200 | 5,000 – 7,000 |
90,001 – 120,000 | 1,400 – 2,000 | 4,200 – 6,000 | 7,000 – 10,000 |
120,001 – 150,000 | 2,000 – 2,500 | 6,000 – 7,500 | 10,000 – 12,000 |
150,001 – 180,000 | 2,500 – 3,000 | 7,500 – 9,000 | 12,000 – 15,000 |
Understanding Your Oil Furnace Power Requirements
Components of an Oil Furnace That Need Power
An oil furnace requires electricity to operate various components.
The ignition system sparks to start the furnace. The blower or fan circulates heat throughout your home.
Pumps move the oil from the tank to the furnace. Each of these parts requires power and contributes to the overall energy consumption of your heating system.
Average Power Consumption of Residential Oil Furnaces
The typical power consumption for an average-sized residential oil furnace varies.
However, it generally falls within a range that most households can accommodate.
Knowing the power usage helps you understand the load that will be placed on a generator during operation.
Checking Your Furnace’s Wattage Requirements
It is crucial to check the specific wattage requirements of your own furnace model.
This information can usually be found in the owner’s manual or on a label attached to the furnace.
Knowing the exact requirements ensures that you select a generator with the right capacity.
Difference Between Starting and Running Watts
Starting watts are the surge of power needed to start the motor-driven components of your furnace.
Running watts are the continuous power needed to keep the furnace operating. Typically, the starting wattage is 2-3 times higher than the running wattage.
This difference is crucial for choosing the correct generator size.
Choosing the Right Size Generator for Your Oil Furnace
Generator Sizing Rule of Thumb
As a rule of thumb, the generator you choose should have a capacity at least 20% higher than your furnace’s peak requirements.
This ensures that it can handle the startup surge and maintain smooth operation during a power outage.
Generator Size Examples for Common Furnace Wattages
For an oil furnace, a generator size of 5000-7000 watts is usually sufficient.
To illustrate, if your furnace has a running wattage of 1500 and a starting wattage of 4500, a 5500-watt generator would typically be adequate to cover the surge and maintain operation.
Accounting for Other Appliances During Power Outages
When selecting a generator, also consider other appliances or necessities you may need during a power outage.
This could include a pellet stove, lighting, or refrigeration.
It’s important to calculate the total wattage these will require to ensure your generator can handle the load.
Using a Transfer Switch for Safety and Convenience
For safety and convenience, it’s important to use a transfer switch with your generator.
This switch allows you to safely connect the generator to your home’s electrical system and prevent back-feeding, which can be dangerous to utility workers and damage your electrical system.
Additional Considerations for Generator Selection
Fuel Types and Availability During Outages
Different generators run on various fuel types, such as gas, propane, and diesel.
Consider the availability of these fuels in your area, especially during a power outage.
Propane and diesel can be stored for longer periods, which might be beneficial in extended outages.
Portability and Storage of Generators
Consider the portability and storage of your generator. If you need to move it around or have limited storage space, a portable generator might be the best fit.
Make sure you have a secure, dry place to store your generator when it’s not in use.
Residential Noise Level Considerations
Noise level is an important consideration, especially in residential areas.
Generators can be loud, so look for models that are designed to run quietly. This will minimize the disturbance to you and your neighbors.
Maintenance of Different Generator Sizes and Types
Each generator size and type has its own maintenance requirements.
Smaller generators typically need more frequent maintenance than larger ones.
Regular maintenance is key to ensuring your generator operates reliably when you need it most.
Long-Term Cost Considerations
Finally, consider the long-term costs associated with different generators.
Fuel efficiency and durability can affect the overall cost of owning and operating a generator.
Weigh these factors against the initial purchase price to make a cost-effective decision.
FAQs About Generator Size for Oil Furnace
What size generator is typically needed for an oil furnace?
A generator size of 5000-7000 watts is usually sufficient for an oil furnace.
Do I need to consider startup surge when selecting a generator for my oil furnace?
Yes, ensure the generator can handle the furnace’s startup surge, which is typically 2-3 times the running wattage.
Can a 5000-watt generator power an oil furnace?
Yes, a 5000-watt generator can typically power an oil furnace, but check the specific startup wattage requirements of your furnace first.
Is a 7000-watt generator too large for an oil furnace?
No, a 7000-watt generator is not too large and can provide additional capacity for the startup surge or other appliances.
How do I calculate the generator size for my oil furnace’s startup surge?
Multiply the running wattage of your oil furnace by 2-3 times to estimate the wattage needed to handle the startup surge.
Final Thoughts
When selecting a generator for an oil furnace, a unit ranging from 5000 to 7000 watts will typically suffice.
It’s crucial to choose a generator capable of handling the initial surge in power demand, which is often 2-3 times the running wattage, to accommodate the furnace’s startup requirements.