Whole House Generators and Your HVAC System

what does a whole house generator cost?

Keeping Your Cool When the Power Is Off

California, and in particular the Bay Area, has experienced a tremendous increase in wildfires. Not only does the smoke contribute to poor air quality, but wildland fires are also accompanied by periodic power outages. That’s where whole house generators come in.

No power means no air conditioning. And no functioning HVAC means poor air quality in your home. 

A lack of air conditioning during the summer months, with temperatures getting hotter every year, is not only uncomfortable, it can literally be suffocating. 

The problem is that in the midst of rising temperatures everyone turns on their air conditioning for relief, putting further strain on the power grid. 

That means it is no longer a matter of if the power grid goes down, but when it will, as power shortages are now a regular fact of life. 

How can you keep your home not only comfortable, but safe, when your power shuts down and you can control neither the temperature nor the air quality?

Many homeowners have turned to solar panels with battery backup. However, not all homes have the proper exposure to take advantage of solar power. If this is your situation, the answer to maintain power even when the electric grid goes down could be to install a whole house generator.

Many homeowners have no doubt heard of whole house generators, but are mostly in the dark about the details. To shed some light on the subject, in this post we’ll explore:

  • What a whole house generator is and how it works
  • How a whole house generator ties into your HVAC system
  • Why installation is not a DIY project

What Is a Whole House Generator?

A whole house generator is permanently wired to your electrical system and is designed to start automatically—usually within 30 seconds—following a utility outage. As soon as power comes back on, the generator shuts down automatically.

The generator sits outside your house just like your outside air conditioning unit. Unlike the AC unit, the generator requires a separate fuel source, either natural gas or liquid propane, or sometimes both. There are also battery-powered generators that store energy from a solar panel or the utility grid; proponents of this type of generator argue that they are more energy efficient and require less maintenance. 

A whole house generator is not to be confused with a portable generator, which is usually powered by gasoline, has a limited running capacity and while it can keep the lights and refrigerator on, can’t power central air conditioning. 

Some permanently attached generators are only designed to keep the refrigerator running in addition to a few lights and maybe one TV. If your concern is to make sure your food doesn’t spoil and that you have an entertainment source during a power outage, then that might be enough.

But if you want to keep the inside temperature at a certain level and continue to purify your inside air, you are going to need a unit with capacity to power your HVAC system.

Larger capacity, of course, comes with a larger cost. But if comfort is a priority, and especially if you have family members with health issues, particularly respiratory issues, it is probably a more than worthwhile cost. 

“Watt” Size Generator Do You Need

The size of the generator is measured in wattage; the more wattage, the more appliances and rooms in your house you can keep running during a power shortage. As an example, a 12,500 watt generator could probably power most major appliances and lights in an average sized home. 

Calculating wattage is not simply a matter of looking at the wattage of each appliance and adding them up. Appliances such as air conditioners and refrigerators cycle on and off, and draw more wattage when they are cycling on. This normally requires two to three times more wattage than “regular” running time. Also, air conditioning units are measured in tonnage or BTUs (British Thermal Units), so an additional calculation is needed to translate these measurements into watts. 

If you estimate a wattage that is too small, the generator overloads trying to supply more energy than it is capable of. This can not only fry your generator, but the connected appliances.

Should you figure more wattage than you really need, you pay more money than you need too; not just for the cost of the generator, but the cost to operate it as well.

To get an accurate determination of the wattage you need during an outage, consult a whole house generator contractor.

How Does a Whole House Generator Work with My HVAC System?

There are a few things to look for when considering a whole house generator to help run your HVAC system during power outages. A key determinant is whether you have a combination of gas and electric heating and cooling system (which uses an outdoor heat pump), or an all-electric system (which uses an outdoor condenser).

For either type of system you have to power the outdoor unit as well as the blower motor inside in order to move the air throughout the home. So you need to know the start up amps for the unit. This is usually a higher amp draw to initiate the start up of the compressor and fan motor on the outdoor unit. If the load is too high it will trip the breaker and your generator will not be able to produce the power needed. 

All of which is why you need an electrician and/or a certified home generator contractor to figure these things out.

If your contractor says the start up amps are too high, not to worry. You can have your HVAC professional come out to install a Soft Start Kit. This helps reduce your initial load amps up to 68 percent, allowing the system to start up in stages. 

Once the system starts up, the running amps tend to be quite a bit lower than the start up amps. So you just need to make sure your generator can handle the running amps while still powering the other desired items in your home as needed.

Why This is Not a DIY Project

If this all sounds a bit confusing, rest assured that it is not for a professional whole house generator and HVAC contractor. If you are looking to install a whole house generator, this is not something you could or should do yourself if you don’t have professional experience.

If you are in the market for both a generator and a HVAC system upgrade, make sure to inform your HVAC professional. They can help you decide on the right system for the specific needs you are looking for, ensuring the system will pair with your new whole house generator and still achieve the heating and cooling you need to stay comfortable as well as stay safe. 

You can also look into a multi-stage heating and cooling system that comes with the capacity to start in different stages to allow for a lower initial amp draw and lower running amps. Do not forget to ask for upgraded in-home purification and filtration systems to help with the smoke particulates. 

Keep Your Cool with Ongaro and Sons 

Finding a certified contractor that can install the correct sized generator for your home is very important. Ongaro and Sons wants to keep you cool and safe at all times, regardless of the situation. Click here for further reading about adding A/C to an existing HVAC system.

For the time being, we can provide you with a gas line for the generator as well as consult on your HVAC operation during power outages. Very soon, however, Ongaro and Sons electrical division is coming to provide you with a one-stop shop for whole home electric  generation. Be on the lookout for this exciting addition to our offerings!