A centrally-ducted heat pump can reduce your CO2 emissions, but did you know you can maximize your impact by optimizing some commonly- overlooked settings? This estimator will let you find the configuration that works best for you!

Note that this estimator is designed to help you explore the possible cost and CO2 impacts for typical heat pump installations in the VGS service area. It provides estimates only based on various assumptions, including assumptions based on typical gas usage and costs of electricity; these are estimates only and are not guarantees of any specific savings as it relates to either cost or carbon emission reduction. To learn more about how it works, and the inputs and assumptions used in the calculations, please see our FAQs below.

To get started, we’ll need to know a couple of basic facts about your home.

Hybrid Heating Carbon Cost Estimator FAQ

A Hybrid Heating system is the pairing of two different appliances such as a fossil fuel furnace and an electric heat pump to provide heating and cooling for your home.
The Estimator is for homeowners who have or are considering pairing a centrally ducted heat pump with their existing furnace. The Estimator will help the homeowner understand the differences in energy costs and carbon emissions associated with using the heat pump vs the furnace.
The Carbon Cost Estimator estimates how much your home's heating might cost and how it affects the environment. It looks at the size of your house, whether or not it’s been weatherized, the Vermont weather, and some other important details to do the math.
It chooses the right-sized heat pump and checks how well it works in different temperatures outside. When it's not too cold, it estimates how much it costs1 and how much carbon (CO2) is produced by running the heat pump (the primary heating appliance). When it gets colder, and the gas furnace is running, the estimator performs the same cost and carbon calculations. The user of the Estimator gets to set the outside temperature at which the primary and back systems function.
The Estimator lets you estimate cost and carbon for some general home sizes and insulation levels. If your home is much bigger or smaller than the sizes we use, or if it's really good or not so good at keeping the heat in, the estimate may not be right. The same goes for how well the gas furnace works. See the Calculation Methodology documentation for more information.
The calculations are based on high-quality heat pumps that work well even when it's very cold outside. If you use heat pumps that aren't as good, they might not save as much CO2, and it might cost more to use them. You can learn more about cold-climate heat pumps at this website: https://ashp.neep.org/ The specific heat pumps used in the Estimator are listed in the Calculation Methodology documentation.
We do our math using weather information from NOAA (the same agency that runs the National Weather Service) that is based on the weather in Burlington, VT over many years. This helps us estimate how much heating we need for an average year. But sometimes, the weather in real years can be hotter or colder, and homes in different places might have different weather.
The “carbon” savings estimates show how much you could help the environment by reducing greenhouse gas emissions, which is measured in metric tons of carbon dioxide. We calculated this using data from local power companies about their electricity sources2 (including renewable energy credits) and your choice of how much renewable natural gas to purchase from VGS.

1. Electric rates are a blended average of Green Mountain Power and Burlington Electric Department for an average of $0.18/kWh.

2. Both Burlington Electric Department and Green Mountain Power list their electricity as carbon free.