How Energy Efficient Are Heat Pumps?

If you are located in Central or Southern American there is a good chance that you are familiar with heat pumps. You might even currently have one. Maybe you are considering one over your expensive furnace. With the rising cost of gas, it only makes sense to make the switch. Over the years, heat pumps have become an increasingly popular alternative as a means of heating and air. The only problem is, you’ve likely heard they aren’t capable of keeping up during really cold months. So, what the truth? Can these devices keep up and exactly how much money do you stand to save by making the switch?

What Makes Heat Pumps More Efficient?

A heat pump is ingenious in the way that it works. It uses heat transfer to pass on major savings to homeowners. What it does is, regulates temperatures inside the home by moving heating from the indoors to the outdoors. It virtually utilizes the elements around it to heat the home. Sounds kinds of technical and complex, right? It is, and this is why it usually takes a trained professional to track down a refrigerant problem. That being said, here is a general breakdown of how the system works.

When refrigerant is under pressure, it releases a sort of heat. When the compressor, like any other motor, is running it’ll also produce heat. The unit takes these two heats and absorbs them into the refrigerant when they are eventually released into the home. It is virtually a transfer between the refrigerant, the compressor, and the outdoor unit. The amount of power required to perform this action is much less strenuous than what it takes to heat a home with fossil fuels.

In addition to all this, a heat pump can be used to cool the home as well. The process is just the reverse of what was described above. The compressor, refrigerant, and outdoor unit will transfer the hot air indoors to the outside of the home while introducing cool air into the home. If you go outside on a warm day, you’ll notice that the outdoor unit is shooting hot air out the top. Walk outside on a cold day and you’ll notice that the outdoor unit is shooting out cold out the top. This is the compressor, the refrigerant, and the outdoor unit pulling out the unwanted air. This action is much more energy concussions than that of heating with fossil fuels.

Understanding Energy Efficient Ratings

When it comes right down to it, the energy-efficient rating of a heat pump should be somewhat easy to understand. This is not to say that the actual process is easy because it’s not. It is very technical and involves converting refrigerant from high pressures liquids to low-pressure solids and back. That being said, the overall general theory is simple, a heat pump moves the heat that’s already there and uses it to heat the home. It doesn’t generate heat. This is somewhat similar to the heating system in a car. It uses the heat from the motor, the condenser coil, and the antifreeze. This simply results in heat pumps being rated in a Seasonal Energy Efficiency Rating (SEER).

Since a heat pump does both heating and cooling, there are several factors and equations involved with determining the overall energy rating of that unit. The SEER rating is something that is based on an annual period where the climate conditions will greatly factor in. The SEER ratings for units in Florida will be much, much different than that of the units sold in Kentucky or Georgia.

Of course, this doesn’t mean there aren’t times when a heat pump won’t work hard and won’t be less efficient than a fossil fuel unit. This is why these units are only suitable for Central and Southern Americans. If there is a huge, significant variation between the input and output, the unit will expend much more electricity to satisfy the temperature in the given space. As you already likely imagined, certain climate conditions make these temperature variations even greater. When this is the case, the efficiency of a heat pump is reduced greatly. It might not even be feasible owning one in some climates, and this is why most people don’t.

Know The Temperatures Ranges

Since heat pumps transfer heat, rather than generating it, the ambient temperature plays a major role. Most of the units of this design will only be effective at temperatures of 25 to 40 degrees F. You get anywhere above or below these temperatures and these units just aren’t going to be feasible. The unit will not be able to generate the required energy to heat or cool the home.

Unfortunately, the winters are anything but mild in New York. There are times when the temperatures are mild, but most of the time, during the winter the temperatures can reach down into the zeroes or below, which would render a heat pump useless. That being said, this doesn’t mean that a heat pump still isn’t feasible. Of course, the heat pump mode of the unit won’t be able to keep up, but there are now different stages of heat available. You’ve likely heard of electric heat, heat strips, or element heat.

These are all virtually the same thing and they are oftentimes installed with heat pumps to help compensate in areas where the temperatures commonly drop below desired ambient conditions. This mode of heat will use more power than a heat pump, but if you cycle between the two options when applicable, you’ll likely still save more money on your energy bills than what you would if you were using fossil fuels for heat. Not to mention the fact, you won’t be harming the environment.

For people that are located in areas where temperatures are commonly below targeted conditions or where it is winter most of the year, there are other options available. One of those options would be what is known as a geothermal heat pump. These units draw energy from underground sources to heat and cool. Of course, there are certain soil conditions and geology that are required for the proper installation of these units. You usually have to be located near a pond or source of water, as these units utilize water.

The Two-Stage Compressor Heat Pumps

There was a time when the early heat pumps only utilized one stage of heating. This is no longer the case, thanks to technology. Technology has now afforded homeowners the options of two-stage compressors. These compressors work as you would imagine. They utilize the second stage, which is the more powerful stage when needed. While they aren’t nearly as energy-efficient as the first stage operation, your unit will mostly run in the first stage around eighty percent of the time.

The unit will switch back and forth between the two modes of operation based on the demands of the home. If the temperatures become too great between the input and output, the unit will automatically kick into the stage two-cycle.

Another thing to note is, these compressors generally have longer cycles, which allow them to better condition the indoor air. They’ll completely remove all the humidity from the home during those hot, summer days. When looking to truly optimize your home’s indoor air quality, you likely won’t find a better or more energy-efficient solution.

The Variable Speed Heat Pumps

There are now more energy-efficient options available for the blower motors as well. The blower motor is a huge part of the system, as it is the component that circulates air throughout the home or building. These motors usually come rated in different sizes based on the demands of your space.

There is now something available known as the variable-speed blower motor. It is virtually what the name says, as it is capable of adjusting its speed to meet the desired conditions. Sometimes the motor can satisfy the temperature in the home while just running at half speed, whereas sometimes it’ll have to ramp up to full speed to satisfy the heating or cooling demand.

Whatever the situation, one of the top benefits of these devices is, they are not only more energy-efficient, but they offer a much quieter operation. These units are also capable of reducing the overall humidity in spaces by as much as 30 to 50 percent. If you are looking for more energy-efficient solutions in New York, you cannot go wrong with the variable stage motor. Combine this with the two-stage compressor and you’ll save yourself even more money.

The Proper Sizing For Heat Pumps

You’ve likely noticed that there is no one-size-fits-all solution for homes when it comes to heat pumps. Some buildings are bigger than others and some buildings are smaller. This is why heat pumps were designed to handle these different conditions. The sizing of these devices will be crucial to the overall operation of your unit. Choose a unit that is too big and you’ll end up with nothing but short cycling.

Choose a unit that is too small and the unit will just likely run and run without ever satisfying the temperature. This is why the sizing is critical. If you are living in a home with an existing unit, likely, your unit has already been properly sized. This is something that is done during the initial installation. However, if you’ve added on or taken away from the home, your home’s heating and cooling demand have likely changed, meaning you might now need a different sized unit.

This is something you’ll want to consider and speak about with your friendly, local HVAC tech. Another thing to consider is the sizing of the ductwork. The ductwork must also be sized appropriately with the size of the unit. If a duct system isn’t properly sealed it can make your unit work harder as well and you’ll lose on your energy consumption. These are all things you’ll want to discuss with your local heating contractor.

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