Find Out What Generator Size Do You Need to Run a House!

Let’s picture a scenario:

Due to a natural disaster or a technical error, your neighborhood loses power. You rush to start your generator, and within minutes, your house goes black again, your appliances are not functioning, and your generator is on fire. 

You do not have power for the rest of the crisis and suffer greatly, with no escape… but why did this happen in the first place?

Would you believe us if we said it was because of a simple miscalculation?

You will be surprised what misjudging your generator’s wattage can lead to, which is why you need to learn the basics of sizing your generator according to your needs:

All The Different Sizes 

It is best to know all the generators available in the market for your reference. So you make up your mind before purchasing the power source blindly. 

Just remember, the wrong wattage can cost you a lot of time and effort. 

The industry categorizes the generators into different groups based on energy and portability

1. Up to 1000 watts – Recreational Inverters

Image of a 1000-watt generator manufactured by Hyundai.
Image source:

Recreational generators help power only essentials, usually on a trip. These devices are not made to sustain a house and will overload if forced. They have an energy supply of approximately 1000 watts

This amount of power helps them support one heavy appliance, with a running wattage up to 800 watts and smaller electronics. This vital device could be a refrigerator, washing machine, heater, etc. 

Such generators are mainly used for outdoor activities, such as RV drives, tailgating, camping, and hiking

A Quick Evaluation:

A recreational generator is commonly known as a portable generator due to its high mobility and lightweight. Furthermore, it is quiet and peaceful to use, as it does not have much power to produce. 

These generators do not require intense installation and can be initiated by a beginner without any difficulty. 

However, they have their shortcomings too. For example, recreational generators can often be overestimated and result in disasters during a vacation. 

Moreover, it is impossible to operate a portable generator in recreational sites without enclosure or covering due to the changing weather. Therefore, you need to be prepared for incoming rain, snow, winds and protect your generator accordingly. 

To find out more about generator coverings and shades, you can visit our webpage here. 

2. Up To 5000 watts – Essentials Only!

Image of a 5000-watt generator manufactured by A-iPower.
Image source: 

Families and offices facing terrible weather conditions only once or twice a year often rely on fundamental electronics during an electrical blackout.  

Since they do not require continuous aid from generators and need to prepare for the rare occasions of emergency, they save cost by buying a generator with limited power.  

The essential gadgets could include refrigerators, washing machines, stoves, lights, heater, air conditioners, and a few lighter appliances. 

A Quick Evaluation:

The average range for this generator is 3kW to 5kW, and it is the perfect secondary power source for individuals on a budget. It is cheaper than the standby or whole house generator and does not waste electricity. 

Mid-ranged generators often allow dual-fuel variations, which have countless benefits, including eco-friendly and cheaper maintenance.

Unfortunately, these generators are not fit to run entire buildings and houses for prolonged periods. As a result, they fail to sustain any house and require new fuel regularly. 

Maintenance of a 5kW generator is usually a lot if you want the best experience. 

3. Whole House Generators – The Father Of Them All

Image of a whole house generator manufactured by Kohler Power.
Image source:

Also known as standby generators, whole house generators can simultaneously power all household devices. They provide up to 20kW of energy and allow a seamless switch between your power sources during a blackout. 

These power sources are owned by big businesses and families with big budgets. Moreover, they are the first choice for individuals living in constant poor weather conditions.

When blackouts are regular, you go for a whole house generator. It provides you with a comfortable lifestyle and a warm home during emergencies or natural disasters.

A Quick Evaluation:

A whole house generator is expensive, with a hefty cost of $10000. In addition, it requires regular maintenance and the utmost care

Any small mistake could result in significant problems. 

Furthermore, the fuel cost and installation are additional expenses that you might forget but shouldn’t. 

Whole house generators are ideal for people wanting a quiet environment during outages, natural calamities, or bad weather conditions. Of course, the convenience comes at a cost, but it might just be the right choice for you!

Onto The Math!

You need to figure out which one of these generators you will require to support your house during a dimout. To settle on a generator, you will need to determine how much power output you require

There are specific steps to follow to calculate the total energy needed.

Step #1 – Put Your Priorities in Order

You should make all your crucial decisions before emergencies. This includes the devices you plan to run during an electrical blackout.

You need to know what your family requires and make a list accordingly. The most common appliances on the list are basic household machinery

If anyone in your house is on life support or uses electrical medical equipment regularly, you need to put them at the top of the list. It is best to include any small and chargeable tools in case of prolonged disasters. 

Remember, your safety and healthcare are always a priority. 

Step #2 – The Calculations

Once you have completed the list of all the devices that your generator will support, it’s time you calculate the exact amount of power needed. 

While referring to a professional for a proper consultation is a good idea, it is not always feasible and affordable. Furthermore, many of you might lack access to help that will benefit you. 

Thankfully, you have us to help you out!

Every device requires a certain amount of energy to function efficiently, and this energy includes the kick-start and running power

Starting Wattage: 

Starting wattage or surge power is the wattage required by a device to initiate its motor, and it is the highest wattage any appliance requires and lasts for only a couple of seconds. This peak wattage is compulsory in calculations and must be taken into account. 

Running Wattage:

Running wattage is the electrical supply a device needs to maintain, and it remains consistent throughout the usage.

If the power supply does not fulfill either of these wattages, the device fails to initiate and run efficiently.

This information is placed on the labels of any electronic device and can be noticed with ease. Both of them should be considered separately when deciding the power for your generator. 

Now, you need to do the math according to a simple formula:

The total energy required by the generator = total running wattages + peak starting wattage

You need to consider the running wattages of all the appliances in the list and the highest starting wattage.

In simple words, it’s the addition for all running wattages plus one starting wattage. 

The Internet Helps!

Several beginners hate the sound of math, and we understand you! Unfortunately, calculations are not a cup of everyone’s tea.

Hence, we have a simple solution for you. Websites are working to provide you with an effortless experience with a generator. This is why a calculator was invented to help you compute a good approximation of your household needs.

This is one of the websites that will do the work for you. It is often that beginners take help from automated sources to prevent errors in their mathematical labor. 

Step #3 – Precision Might Doom You!

Once you have totaled the energy supply, you need to consider extra wattage before buying your generator. This additional wattage takes the burden off your backup power source and makes it more efficient. 

It is highly recommended to buy a slightly bigger generator than the calculated power. You may end up damaging your generator if you play by your rules, and here’s why:

1. Overloading – A Generator’s Crutch

It is easy to overload a home standby generator, as you want to take maximum advantage of the power source. You can fry out the panels on your generator or overheat it when this happens, causing a short circuit and fire.

Moreover, your energy source might not even function after sensing the extra load and shut down immediately. This is treatable most of the time, but you will not always be this lucky.

Hence, you could use a few extra wattages to aid you when you are not thinking straight. After all, blackouts can be pretty stressful.

2. Beware Of The Risks!

A generator running at maximum load is a ticking bomb and can set off at any moment. It is a major fire hazard and almost inevitable.

It can result in severe internal damages, permanent breakdown, and, unfortunately, even an explosion

Warning: This is not an exaggeration!

An electrical outage due to a nationwide crisis can be daunting and difficult by itself. You do not want your family to suffer more during such intense times. A few extra watts can be the difference between a peaceful evening and a disastrous one. 

3. One Last Breath…

A generator with excess charge is far more efficient than a strained one, and It burns fuel more effectively and prevents damage to any running appliances. 

Generators used with full load regularly tend to wear after a few years of operation. As a result, they do not fulfill their purpose throughout their function and are essentially a waste of money

With extra load, your power source can provide better results and help for a longer time to your homes. 

4. Save The Bucks

With fewer maintenance runs and reduced damages, additional costs of keeping a generator are removed, and you have a more pleasant experience with the device. 

A bigger generator might be slightly expensive; however, it is an investment into your future and will benefit you indefinitely.

It Is Complicated!

Sizing a generator can be tricky because you shouldn’t overcompensate and also can’t underestimate its power

A generator too small has the risk of blowing up, while overcompensation will be a waste of money and maintenance costs. Therefore, you need to invest proper time and effort to decide the ideal generator size you and your family need. 

Do not take this lightly and cut any slack in this matter!

The Talk Of Essentials 

You should have proper knowledge about the devices in your house and how much power they take to operate. This information can be found in the labels, accompanied manuals, and the manufacturer’s websites

However, we decided to provide you with a good estimate of all the common household appliances to make your life a little bit easier! 

Chart of Household Appliances and Their Wattages:

AppliancesStarting Wattage [watts]Running Wattage [watts]
Ceiling Fan7060
Clothes Dryer67505400
Electric Heater (Fan)2 0001 000
Electric Thermal RadiatorN/A500
Electric Water HeaterN/A4 000
Electric Water Heater (tankless)6 6002 200
Flat Screen TV120120
Furnace Fan Blower (1/2 HP)2 350800
Furnace Fan Blower (1/3 HP)1 400700
Garage Door Opener2 350875
Heat Pump4 7004 500
LCD Monitor3030
Light Bulb (conventional type)N/A75
Light Bulb (LED)N/A9
Space HeaterN/A1 800
Sump Pump (1/2 HP)2 1501 050
Sump Pump (1/3 HP)1 300800
Washing Machine22501150
Well Pump (1/2 HP)2 1001 000
Window AC (12 000 BTU)9 7503 250
*These values are merely an estimate; your appliance’s power consumption may differ

Some of these appliances take priority over others during a blackout and need to be considered first when making the requirements list. 

However, if you are uncertain of what to put on your list, this will give you an idea: 

Refrigerators – Can You Survive Without Food?

It is a given that in a crisis, you need to have a stable supply of food and secure storage space. If the outage is elongated, you need frozen goods and fruits in their original quality. 

This is why you need a working refrigerator during an emergency, so you do not lose the one hope for survival after a power source. 

TV/ Radio – Keeping Up With The “Kalamities”

While radio and Tv might hold entertainment value in your house, they can be an excellent source of information and updates on poor weather conditions, storms, natural disasters, and global tragedy

Nothing is worse than being in the dark literally and figuratively about the rest of the world. You need a constant supply of knowledge and what’s happening around you to grasp the situation without panicking. 

A mobile phone with an internet connection can be a viable option, too, as nothing is faster than the spread of word through the fingertips of your fellow web users. You will need at least two working sockets for a fully charged handheld device and the modem. 

Stove/Oven – Good Food = Good Mood

A frozen slab of meat and uncooked rice will be of no use without at least one cooking electronic device. You need a working stove or oven to cook your food and serve it with a smile during tough times. 

Canned foods will help you survive, but homemade meals will let you live!

Air Conditioner/ Heater – Where Do You Live?

An air conditioner or a heater is a choice you have to make based on your living conditions. Either of them is necessary to survive frequent outages and do not require a lot of power. 

For families living in changing weather conditions, you can always switch between the two devices to meet the needs of your climate. It is unlikely that you will require the use of both simultaneously. 

Lights/Bulbs – Because Darkness Can Be Frightening

We do not have to convince you to enlist a few bulbs in your essentials for apparent reasons. However, you need to pick the lights in your house strategically. 

You should only allow light to one or two rooms with good ventilation and a view of your neighborhood. Moreover, you do not need more than a single bulb in each room as it’s not a ball party; it’s an emergency. 

Save as much power as you can because you do not have the time to make accurate predictions during an emergency. 

What Else Do You Need To Look For

The size of a generator is essential; however, that’s not all. To have a safe and comfortable experience, you need to consider a few other factors before buying this sensitive electronic. 

Transfer Switch – Simple Solution, Complex Connection

A generator needs to be connected to your house’s main circuit panel during installation, and this attachment needs a secure path that is not easily breakable. 

A transfer switch is your answer!

A transfer switch is a device that allows an instant transfer of energy when the power goes out. It establishes a bond between the primary and the main power source and springs into action. 

It does not need any manual interference and automatically turns your generator on. Therefore, it is preferred by most individuals and requires installation by experts.

CO Detectors – Suffocation Is Not A Cool Way To Die

Generators release lethal fumes, dangerous emissions, and poisonous gases that significantly harm your health. One of the biggest threats is carbon monoxide

Carbon monoxide is a dense gas that can accumulate quickly in confined areas. It can lead to carbon monoxide poisoning, making you nauseous and sick, eventually leading to your death

Excessive levels of CO can cause chronic respiratory problems and need to be tackled with care. 

Hence, most generators are equipped with carbon monoxide detectors. These devices alert the user about the build-up of said gas and ring the alarm. Additionally, they turn the generator off automatically to let the contaminated air dissipate. 

Starting Mechanism – Which One Is For You?

Modern generators require the push of a button to begin operation, and this is called an electric start and is most beginners’ favorite. 

A complete opposite of this mechanism is the manual start. This requires the pull of a recoil cord repeatedly to kick start the device and produce power. Manual start can be slightly complex as it was the pioneer method of initiating a generator. 

Remember, before starting any generator; you need to check if your generator is ready. The checklist includes the fuel quantity, a stable connection, a secure location, etc. 

Total Harmonic Distortion – Let’s Simplify It!

THD orTotal Harmonic Distortionis a measurement for the potential damage of a device. It is commonly found in sensitive electronics and should be avoided when purchasing an appliance. 

A standby generator needs to have a THD value under 6% and should be your go-to choice. 

Check the retailer’s website for a generator’s THD value before purchasing it. You can also contact an electrician to gain proper knowledge about your choice of generator.

What Is Wattage?

Watt is a unit used to measure the energy/power utilized by your generator. It varies for each device, and the bigger the appliance, the higher the wattage. 

Most companies place the wattage of a device on an information label on the device. However, some settle for other Amperes (A) and Volts (V)   units.

You can just copy the wattage printed on the label, but you need to find it indirectly if it is not mentioned. This will involve the other units. 

The formula connecting the three elements is:

Watts = Amps x Volts

You Will Thank Yourself!

After reading this detailed guide about sizing your generator, you should make a wise decision. The calculations may seem overwhelming. , and however, we assure you they are not. 

It takes time to gather all the information, plus different wattages and units can be tricky, but nothing you can’t overcome with a bit of effort!

In the end, when you sit peacefully amidst the chaos of a blackout, you will be thankful that your generator did not give up on you. 

And It Was All Possible Because Of You!

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