Updated January 18, 2024

A home standby generator can be a great addition to your house. This type of unit is wired into a home’s electrical system and will automatically supply electricity to the residence any time a blackout occurs. While your neighbors are stuck sitting in the dark, a home generator will allow you to turn the lights on, keep the food in your refrigerator cold, and even run your heating or air conditioning. That is, as long as you make sure to choose a generator that is large enough to effectively power your home. You also obviously don’t want to opt for a generator that is much too big since this will just be a waste of money. This guide will show you the different factors you should consider when choosing a home generator so you can make sure the unit is exactly the size you need.

Calculating Your Energy Usage Requirements

A home standby generator won’t always need to power everything in your house at one time. Most units can be paired with an electronic controller to allow you to prioritize only the appliances and other things you must have at that moment. This is called load management, which we’ll cover in more depth in what follows.

Load management is useful for ensuring that everything you need to use has power without potentially overloading the generator and causing it to shut down. Nonetheless, you still want to ensure that the generator always has sufficient power to run your lights, heating or air conditioning, refrigerator, and all of the other important things at one time. The easiest way to do this is to write a list of everything you think you may need to power during a blackout. You then need to find out how many watts per hour of electricity each thing on the list uses. In this way, you can ensure that your generator isn’t undersized.

If you have LED light bulbs, each one will use approximately 10 watts per hour. Of course, you typically won’t need to have all of the lights on in your home at once so you should focus predominantly on the things that use the most energy and are the most important. This would include your refrigerator and freezer to ensure your food doesn’t spoil. If your power is out for a long time, you’ll probably want to make sure that at least your primary TV still has power, and it should also go on the list. If you have an electric cooktop or oven, you’ll want to at least estimate how much power that requires as well.

If you have an outdoor hot tub that you keep filled in the winter, this should also go on your list. Otherwise, you will probably need to drain it to prevent it from freezing if the power goes out for an extended time in the winter. Your hot tub isn’t a necessity, but it’s still something to consider to ensure it doesn’t get ruined. Anyone who owns an electric vehicle may also want to factor in their EV charging station since many public charging stations don’t have backup power and won’t work in a blackout.

Evaluating Your HVAC System

In homes with a central AC, heat pump, or ductless mini-split, the main thing you should focus on is how many watts the HVAC unit requires. This is because an HVAC units will generally use much more power than anything else in a typical home other than a hot tub. The other exception is if your home has any type of electric heating. This will also require lots of power. No matter what type of heating system you have, you need to choose a generator that is powerful enough to keep the system running, or your pipes could easily end up freezing if a severe winter storm knocks the power out.

You don’t necessarily need to make sure you can run your air conditioning during a blackout, but it will help to keep your home more comfortable. It’s also a good idea just in case you lose power during extremely hot weather. Otherwise, your home could get dangerously hot and put you at risk of heat stroke.

When evaluating the energy needs of your HVAC system, you should always focus on how much power the system uses when starting up. Most HVAC units draw around three times as much electricity when turning on compared to what they use when running. If your home has a 3-ton AC or heat pump, it will typically use anywhere between 2.4 and 3.3 kilowatts per hour (2,400 to 3,300 watts) when running, depending on how energy efficient it is. The HVAC blower will also usually use around 0.5 kWh. However, a system this size would normally draw around 9 to 12 kWh when first starting up. Consequently, you’d typically want to have at least a 14-kWh generator to ensure the HVAC system can start without having to take away power from almost everything else in the home.

Managing Energy Loads

Your generator will always need to produce at least a bit more energy than your HVAC system needs to start. Nonetheless, load management can allow you to get away with a slightly smaller generator than you’d otherwise need if it had to power everything in your home at the same time. By connecting an electronic controller to the automatic transfer switch that controls the generator, you can prioritize certain things in the home. This allows you to set it up so that not everything in your home tries to start up at the same time because this would likely overload the generator.

In most cases, the electronic controller will be programmed so that the HVAC system turns on first and has the highest priority. Once the system is running, the generator will then typically send power to your refrigerator and whatever else is a higher priority. The HVAC system will normally turn on two or three times an hour. Each time the system needs to start, the controller can then temporarily divert power from the lower priority things to ensure the generator can easily supply all of the additional electricity needed for the HVAC system to turn on.

You’ll need an electrician to install the generator, connect it to your electricity system, and program it to ensure the unit always powers everything you need. The first step will be to have the electrician perform a load calculation, which means evaluating your home and its energy needs to determine what size of generator will work best. This is something that the team at Golden Rule can help with because we offer expert home generator installation services.

When you’re looking to install a home generator, our electricians will help you determine what size of unit you need and which option will best meet your energy requirements. We can then keep your generator properly maintained and handle any repair needs as they arise. Our team can also help if you need any other electrical services in Grimes or the Des Moines area or if you need any plumbing, heating, or air conditioning services. For more information on your home generator options, give us a call today.

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