How Efficient Are Heat Pumps?
“Energy efficiency” refers to the amount of energy a device needs to perform a certain task. With regards to heating, a more efficient system requires less power to generate usable heat energy. There are plenty of reasons to opt for a more energy-efficient HVAC system, with the cost-benefit being the most obvious. The more efficient your furnace or air conditioner is, the lower your overall energy costs will be.
One of the most popular new technologies for heating the home is the heat pump. How do these newfangled systems measure up, though? How efficient are heat pumps? Is it worth installing one in your home? And if you do decide to install one, where do you begin?
How Is Energy Efficiency Measured?
The second law of thermodynamics states that you can never get more energy from a system than you put into it. Simply put, the laws of physics being what they are means that some energy is always lost when you are creating heat, or using energy to do anything else for that matter.
A more efficient system just means that less of this energy is lost. Modern technologies are usually significantly more efficient than older ones. We simply have to look at a modern LED light bulb versus an old-school incandescent one, for example. The efficiency is measured in the amount of useful light energy the light bulb can generate for every watt of electricity that is introduced into it.
An incandescent bulb creates about 10 to 17 lumens (a measurement of light energy) per watt. A modern LED bulb, on the other hand, generates about 90 to 112 lumens per watt! So while neither light bulb is able to effectively use all of the electricity that’s put into them, one bulb emerges as the clear winner in the energy efficiency competition by utilizing a lot more electricity effectively.
When it comes to heaters, they operate much the same way: power is put in, and heat energy comes out. With a furnace, heat energy is measured by what’s known as the AFUE standard: this stands for the annual fuel utilization efficiency. It calculates the percentage of power that can be transformed into usable heat energy.
How Can I Tell If My Heater Is Energy Efficient?
Because it helps to reduce the carbon footprint of a home, the federal government, as well as most local governments, have worked to incentivize the use of more energy-efficient heating technology. This often means that it’s actually illegal to purchase a new heater with an AFUE rating of less than 80 percent, although you shouldn’t have too much trouble getting a heater that’s a lot more efficient than that.
The best way to ensure you have an efficient heater is to look for the Energy Star rating. This is a logo placed on certain technologies by the US Environmental Protection Agency to indicate that they are highly efficient. Particularly efficient heating methods can often have an AFUE rating of as high as 98 percent.
How Are Homes Usually Heated?
A traditional furnace generates heat through the burning of some sort of fuel source. Among the most popular fuels in use today are propane, natural gas, oil, coal, and wood. Electricity can also be used directly to generate heat using a method called resistance heating. As you might expect, each of these methods of generating heat energy is vastly different from each other, especially with regard to efficiency.
For example, generating heat energy using electricity is considered to be extremely inefficient. Because electricity is used directly to generate heat, it takes a lot of power to get a home to a comfortable temperature. Electric heating has other benefits, such as a reduced fire hazard due to the lack of a combustible fuel source, but energy efficiency is decidedly not one of them.
More efficient methods of heating the home include propane, which burns extremely hot and so can get a house to the desired temperature with decidedly less fuel, and natural gas, which has similar properties. Wood and coal furnaces are considered to be less efficient and more expensive to operate.
What Is A Heat Pump?
A heat pump differs from traditional furnaces because, unlike them, it does not utilize a fuel source at all. While it is powered by electricity, it just uses this electricity to run its systems, not to generate the heat itself. Therefore, it requires less electricity to operate than a resistance heater.
So, if it’s not burning fuel to generate heat, where is the heat energy coming from? With a heat pump, the answer is in the name: it’s not generating heat at all but simply utilizing refrigerator coils to pump heat from place to place. Simply put, a heat pump transfers heat energy that is already present in the environment into the home.
While a heat pump is considered the latest in cutting-edge home heating technology, its foundation is actually a very old invention. The modern-day refrigerator coil has been in use for well over a hundred years. By circumventing the need to generate heat, a heat pump also avoids having other large systems such as fans in the home as well, simply venting the energy to where it’s needed. Heat pumps can also be installed in individual rooms, eliminating the common problem that most furnaces have of wasting a lot of heat energy in rooms that are not currently occupied by anyone.
So how efficient are heat pumps? Well, their AFUE rating is often well over 96 percent, but the fact that they can be used to target individual rooms means that their actual efficiency is essentially greater than any other heating method you can buy. And the best part? Their ability to transfer heat energy from place to place means that you can use them to get unwanted heat out of the home too: they double as air conditioners.
Where Do I Get One?
If you’re interested in having a heat pump installed in your home, you’ll need to contact an HVAC professional who is experienced with them. In the Pacific Northwest, this means Entek. We have over 75 years of experience installing the latest in HVAC technology. Our certified, experienced contractors can help you to get your home set up with the latest and most energy-efficient heating technology.
