To determine the size of the generator you need to run your furnace and refrigerator, you'll have to calculate the total power (wattage) required by both appliances and choose a generator that can handle that load. Here's how you can do it:
Identify the power ratings: Check the labels on your furnace and refrigerator to find their power ratings in watts. The power rating is typically mentioned on a data plate or sticker attached to the appliance.
Add up the power ratings: Add the power ratings of both appliances to get the total wattage required. For example, if your furnace requires 1,200 watts, and your refrigerator requires 500 watts, the total would be 1,200 + 500 = 1,700 watts.
Consider starting surge: Appliances like refrigerators often have a higher power draw when they start up. This initial surge can be around 2 to 3 times the normal running wattage. Check the appliance manuals or look for surge/startup wattage information to get a more accurate estimation. In the example above, if the refrigerator's starting surge is 2 times its running wattage (2 x 500 watts = 1,000 watts), then the total surge wattage would be 1,700 + 1,000 = 2,700 watts.
Select the generator size: Once you have the total wattage (running or surge), choose a generator with a rated output equal to or greater than that value. It's recommended to opt for a generator with a slightly higher capacity than the total wattage required to account for any additional small loads or future power needs.
For the example above, a generator with a continuous output of at least 1,700 watts or a surge output of at least 2,700 watts would be suitable to run both the furnace and refrigerator simultaneously.
When purchasing a generator, also consider factors like fuel type (gasoline, propane, etc.), noise level, and runtime on a full tank, as these aspects can influence your overall experience and convenience with the generator.
Remember that if you plan to power other appliances or devices simultaneously, you'll need to account for their power requirements as well to ensure the generator can handle the total load safely. If you're unsure about the calculations or have complex power requirements, consult an electrician or generator specialist for assistance in choosing the right generator size for your needs.