In our continual quest for energy efficient options, more and more evidence has been revealing the benefits of using heat pumps in residential buildings. In this week’s blog post, we will be talking about heat pumps and how they could lower emissions.
What Are Heat Pumps?
Heat pumps are essentially air conditioners that can reverse their direction. In summer, they work as a standard air conditioner. In winter, the direction of the refrigerant can be reversed. Heat is collected and released into the building.
When the aim is to cool the house there is no difference between a heat pump and a standard air conditioner. Both collect the warm air in a house and transfer it outside.
The differences are most visible when in heating mode. Air conditioners are unable to heat a space. A furnace is usually used for heating.
Heat pumps have a special reversing valve. This valve allows the heat pump to absorb heat from the outside and send it inside. No actual heat is generated. It is simply collected from the outdoors and transferred indoors.
There are three most common types of heat pump systems: air-to-air, water-to-air, or geothermal.
How Do Heat Pumps Lower Emissions?
Heat pumps work using electricity. Even when the electricity mostly comes from a coal or natural gas plant, the use of a heat pump reduces the total greenhouse gas emissions of a building.
How does this work? Unlike a furnace, no heat is created onsite. The heat is pulled from the outside air and sent inside. It is generally more efficient to transfer heat than to create it.
A report published in 2019 answered the question, what are the benefits and problems with the electrification of heating homes? This study found that using heat pumps for single-family homes in Texas could reduce carbon dioxide emissions by 3.5 million metric tons and nitrogen oxide emissions by 2,700 metric tons.
In 2018, 30% of Texas electricity comes from renewable sources – 20% being from local wind farms. As we switch from fossil fuels to more sustainable electricity production, emissions will be lowered even more. The study also concluded that “new winter peak demands [on the grid] in the mornings are more aligned with times of strong wind output.”
What Are the Limitations?
Some studies have found that not every house in the nation would benefit from the installation of a heat pump. In some houses, if the electricity is provided solely by a fossil fuel combustion plant, the cost of the electricity could be more than the fossil fuels burned by a traditional furnace.
This option might not be feasible for really cold climates. In 24 studies, peak residential electricity demand increased beyond the grid’s capabilities – an increase of over 100% — if every house in a colder environment used a heat pump.
This limitation could be removed, but that would require large updates to the electrical grid. Since heat pump technology has advanced a considerable amount since it was first discovered in 1855, there are reasons to think it could advance more in coming years.