# Sizing Home Backup Generator



## Redi (Nov 22, 2017)

In sizing a home backup generator is the monthly, daily and/or seasonal kWH data useful?

That is to say, I can easily generate these numbers from monthly bills. Are they useful if determining size of a backup generator to run a critical load during outage?

Comments and advice appreciated.

R


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## KRE (Nov 29, 2011)

A false load calculation will result from those numbers, as back up gen sets are not an infinite buss like your power company.
Tell us if you want to run the HVAC or not, if so is it gas or electric or a combo of both (aka gaspack)?
Do you heat water with gas or electric?
Do you want to be able to wash an dry clothes while the power is out?
Do you want the generator to run the whole house, or just some things?
How many square foot is the home an what state is it located in?
What type of fuel do you what to run, Natural gas, Propane, Gasoline, or Diesel?
Do you wish the system to be completely automatic? 
Do you care about noise?
Do you require a open unit or one that is weather proof? 
What is the budget start to finish?
Correct answers to the above questions will allow spot on sizing, with the worst case of inrush currents an voltage dip possible.

A properly sized an quality unit will give/have a long life cycle, unlike anything from box store.


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## RonJ (Aug 5, 2015)

Treat the purchase like you would an insurance policy...you want the very best - you will never go wrong! I tried to remember some saying, You will be bitter long after the failure of a cheap product, especially when you consider how much you spent. Ron


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## exmar (Jun 29, 2015)

When determining budget, take all the above into consideration and also, how often you "usually" lose power and duration. e.g. Don't spend $10,000+ with a whole house, auto transfer, etc. installation if you only have few outages of short duration. JMHO


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## KRE (Nov 29, 2011)

exmar said:


> When determining budget, take all the above into consideration and also, how often you "usually" lose power and duration. e.g. Don't spend $10,000+ with a whole house, auto transfer, etc. installation if you only have few outages of short duration. JMHO


Interesting that you say that, as I've never had trouble call for an appointment. When my family's safety or convenience is at stake, money has never, an never will, be an issue with me. Especially if there is or might be a medical issue in the home. I find it interesting that people will buy high end toys that when the power go out are worthless. Or spend 10's K of dollars on other toys before for providing their family's safety, with quality.


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## exmar (Jun 29, 2015)

KRE said:


> Interesting that you say that, as I've never had trouble call for an appointment. When my family's safety or convenience is at stake, money has never, an never will, be an issue with me. Especially if there is or might be a medical issue in the home. I find it interesting that people will buy high end toys that when the power go out are worthless. Or spend 10's K of dollars on other toys before for providing their family's safety, with quality.



Valid point. I've known folks who spent a ton of $$ on whole house installations and then a few years down the road, realized that an outage hadn't occurred. We all decide where and how to spend money, just suggesting that frequency and duration of known outages should be a consideration in deciding on type and size of genset.


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