How to Calculate your Heat Pump’s Running Costs?
A heat pump is one of the ways you can keep your home snug and warm during winter. However, since it relies on electric power, you may worry about how much electricity the device consumes. You’ll be glad to know that heat pumps are more energy-efficient compared to traditional ways of heating your home. As such, they can have a lesser impact on your electric bill than, say, a furnace. In some instances, heat pump use may even qualify you for tax credits or rebates.
What is a Heat Pump?
Heat pumps are appliances that use electricity and refrigeration technology to keep the temperature inside your home at a comfortable level no matter the season. During winter, a heat pump provides warmth to your living space, while in summer, it makes your home cooler.
How does a Heat Pump Work?
In a nutshell, a heat pump works by using electricity and refrigerant to transfer heat from one place to another.
To warm a certain space/area, the pump gets the heat from the outside air and transfers it to the refrigerant. This compresses the coolant, increasing its temperature significantly. The coolant then goes into the pump’s indoor unit, which passes air over the heated coolant and releases the hot air into the room. The pump reverses the process when it needs to cool the space.
Heat Pump’s Energy Consumption
Heat pumps are considered the most energy-efficient way to warm your home. The devices can reduce energy use by 50% compared to furnaces or baseboard heaters. Still, because heat pumps use electricity, they can add to your utility costs.
By how much? Well, these devices consume anywhere between 802 watts to 5,102 watts (or between 0,802 kWh to 5.102 kWh per hour). That means it costs you approximately $0.10 to $0.98 per hour to operate your pump. However, how much electricity your device drains depends on a few factors. To figure out how much it actually costs to run your pump, you’ll need to look into the following:
Size or Capacity
The size or capacity (also called tonnage) is one of the primary factors that determines the device’s power usage. The capacity of heat pumps is typically measured by their BTU output. This is the amount of heat the pump produces. The bigger the size of your heat pump, the higher its energy consumption. For example, a 4-ton heat pump takes more electricity to run than a 1-ton unit.
Meanwhile, how big a heat pump you need depends on the area you need to heat. The larger the space that requires heating, the higher BTU output your pump should provide.
This is another critical factor when it comes to your heat pump electricity usage. Highly efficient units require less wattage to operate than less efficient ones. Brands and models with higher efficiency may cost more upfront, but they can help reduce your energy usage, which translates into savings on your electricity bills.
The Seasonal Energy Efficiency Ratio (SEER) rating of a heat pump indicates its efficiency. A 3-ton unit with a 14 SEER drains about 3,061 watts. Compare that with a pump of the same tonnage but with a 22 SEER that consumes 2,406 watts. This shows the big difference in power usage between highly efficient units and their less efficient counterparts.
Types of Heat Pump
Different types of heat pumps exist in the market. Most use electricity while some run on natural gas. You usually base the kind of pump you install on your home’s layout and heating goals.
Meanwhile, the device’s heat pump technology will affect its power usage. In general, air-source heat pumps require more energy than ground-source models, which have higher SEER ratings.
Coefficient of Performance [CoP]
The coefficient of performance (CoP) indicates how efficient a heat pump is. It details the dynamics between the power or electricity supplied to the compressor and the power that the heating or cooling unit produces.
Let’s say a heat pump has a CoP of 3. It indicates that each unit of electricity that goes into the system results in 3 units of cooling or heating power. Generally, a CoP above 1 means the pump is efficient.
Calculate your Heat Pump’s Wattage
Determining your pump’s wattage can be challenging as this information isn’t indicated in the unit’s specification sheet. Instead, what you’ll find is the SEER rating. So we’ll use the SEER to calculate the pump’s wattage using these two equations.
EER = −0.02 × SEER² + 1.12 × SEER
Total Wattage = Capacity (In BTUs) ÷ EER
First, we convert the SEER to EER and then use the resulting EER to compute the total wattage of the pump.
Here’s an example:
A 2-ton heat pump (24,000 BTU) with a 20 SEER
EER at 20 SEER = −0.02 × 20² + 1.12 × 20 = 14.4
Total Wattage (2-ton, 20 SEER) = 24,000 BTU ÷ 14.4 = 1,667 Watts
Using the same equations, here are the wattages of various pump sizes.
|Size of Heat Pump||Wattage (14 SEER)||Wattage (16 SEER)||Wattage (18 SEER)||Wattage (20 SEER)||Wattage (22 SEER)|
|1 ton / 12,000 BTU||1,020 Watts||938 Watts||877 Watts||833 Watts||802 Watts|
|1.5 ton / 18,000 BTU||1,531 Watts||1,406 Watts||1,316 Watts||1,250 Watts||1,203 Watts|
|2 ton / 24,000 BTU||2,041 Watts||1,875 Watts||1,754 Watts||1,667 Watts||1,604 Watts|
|2.5 ton / 30,000 BTU||2,551 Watts||2,344 Watts||2,193 Watts||2,083 Watts||2,005 Watts|
|3 ton / 36,000 BTU||3,061 Watts||2,813 Watts||2,632 Watts||2,500 Watts||2,406 Watts|
|3.5 ton / 42,000 BTU||3,571 Watts||3,281 Watts||3,070 Watts||2,917 Watts||2,807 Watts|
|4 ton / 48,000 BTU||4,082 Watts||3,750 Watts||3,509 Watts||3,333 Watts||3,209 Watts|
|4.5 ton / 54,000 BTU||4,592 Watts||4,219 Watts||3,947 Watts||3,750 Watts||3,610 Watts|
Benefits of Using a Heat Pump
As mentioned, heat pumps can warm your home more efficiently than other heating methods. Using a heat pump daily may increase your energy expenses by around $50 to $100 a month, but that’s less expensive than heating your home using oil or natural gas.
Let’s look at the benefits that using a heat pump offers
- They’re energy-efficient: They require less electricity because they don’t generate heat or produce cool air. Instead, they move the air from one place to another. During summer, they push the heat inside your home outdoors and reverse the process during winter.
- You only use one system for your heating and cooling needs: Heat pumps not only provide warmth for your home, but they cool it as well. That means you won’t have to purchase both an air conditioner and a furnace, which saves on costs.
- They’re quieter: Heat pumps tend to make less noise than conventional HVAC systems. Moreover, because the compressor (the noisy component of the unit) is installed outside, you’re spared the racket it creates.
- They improve air quality: Heat pumps mix inside and outside air, resulting in better air quality. With proper maintenance and effective filtering, you get cleaner, better-smelling air.
- They reduce your home’s carbon footprint: Due to their high efficiency in converting energy to heat, they require less electricity. This reduces the amount of fossil fuels that get burned for electricity generation.
Heat Pumps & Energy Bills
Heat pumps use electricity, so operating one will raise your power bills. Expect an increase between $50 and $100 for running a single unit (or one-to-one) heat pump. However, the pump will reduce your heating fuel bill.
An average household consumes around 800 gallons of oil. Getting a heat pump can slash your oil usage by 300 gallons. Oil costs $2.75 per gallon, on average. That translates to approximately $28.06 per million BTU. Meanwhile, to get the same 1 million BTU of heat from a pump, you’ll spend $14.71, assuming that electricity rates stay at the current standard price of 14.5 cents. That’s 48% less than what you’ll pay if you use oil.
Heat Pumps with Solar Energy
Solar panels harvest the sun’s energy and convert it into electricity. During the day, while the sun is shining brightly, the panels absorb its radiant energy. The inverter then converts this energy to become the kind of electricity used in a home.
In many instances, if the electricity generated by the solar panels exceeds your home’s consumption, you get credits for the excess production. You can use those credits to offset the electricity you get from the grid when the panels’ solar power production is not enough for your needs.
When you use the electricity generated by the solar panels to power your heat pump, you’ll be reducing your consumption of electricity that comes from the grid, which will lower your bill. In effect, you’ll be heating your home for around 9 cents per kWh instead of 14 cents per kWh, which is the amount you’ll pay without solar. Pairing your heat pump with solar panels will reduce its operating costs by almost 40% a year.
Heat Pump Water Heaters
Water heating typically accounts for around 14-16 percent of a home’s utility expenses. This translates to approximately $400 to $600, depending on the electricity rates in the area. Using a heat pump water heater can help bring down that cost.
Heat pump water heaters work the same way as heat pumps. They don’t generate heat but instead pull it from the surrounding air. They Then transfer that heat to the water in the heater’s storage tank. Because they’re well-insulated, they do a good job even in areas with colder climes.
A heat pump water heater can provide hot water at low energy costs. The electricity consumption of such a heat pump for a family of 4 is only around $15.
How to Save on Your Heating Costs?
Using heat pumps instead of electric heaters can lower your electricity bill by about $815 a year. But you can still cut your power consumption if you reduce the operating costs of your unit.
Insulate your House
A poorly insulated house wastes energy by letting hot or cool air escape into the outdoor environment. Thus, you should first correctly insulate your home before installing a heat pump. Putting in a loft and wall insulation can significantly reduce your heating and cooling needs. While you’re at it, plug the cracks and seal the gaps between doors and windows.
Select the Appropriate Heat Pump Size
A heat pump is not a one-size-fits-all proposition. Sure, a small pump can still provide heat for a large area, but it comes at a cost. Having a pump that’s too large or too small can lead to higher bills and expenses, such as repairs and maintenance costs. That’s why it’s essential to choose the right pump size.
You need to consider several factors when determining the size of the pump you need. These include the square footage of your house and the number of people living in it.
Here are some general guidelines regarding the BTU output you’ll need:
- 500 square feet: 1 ton
- 1,000 square feet: 2 tons
- 1,500 square feet: 3 tons
- 2,000 square feet: 4 tons
- 2,500 square feet: 5 tons
- 3,000 square feet: 6 tons
Change the Filter Regularly
A clogged or dirty filter makes your unit work harder to get air flowing. This means that the heating element inside the pump is going to get hotter in transferring heat because there’s a less volume of air that passes through it. As a result, the system becomes less efficient, and worse, it gets worn out faster. A dirty filter also reduces the air quality the unit puts out because it can’t filter out airborne particles effectively.
Ideally, you should change your filter every 3 months to ensure the optimum performance of your pump.
Use a Programmable Thermostat
A programmable thermostat takes the hassle out of tinkering with your pump’s settings every time the outdoor temperature changes. That’s because the device automatically adjusts the temperature to keep your home warm and cozy.
Using a programmable thermostat also lets you preset your home temperature for different times of the day. In this way, you can avoid coming home to a freezing house.
This device can help you save up to 20% on your heating expenses.
Keep Doors & Curtains Closed
Doors and curtains can help your pump maintain the correct temperature inside your living space more efficiently. Keep the door shut to avoid drafts and close the blinds or curtains during cold days. However, if you have a window that lets in plenty of sunlight, you can decide whether to open or close the drapes to allow natural light to warm your space.
Wear a Jacket or a Sweater Instead
Instead of cranking up the heat during freezing weather, you can keep a lower thermostat setting and still remain warm by putting on a jacket or sweater. This clothing article can keep the chilly air at bay even on the coldest days. To have more protection against the cold weather, try layering your clothes and top them off with a fleece jacket.
Use a Heated Blanket
Heated blankets only require enough energy to keep you warm. That’s a lot less than heating a whole room or house. By using a heated blanket, you can avoid jacking up the setting on your thermostat when the nights get cold. This makes heated blankets the eco-friendlier way of keeping yourself warm during the cold winter months.
Use a Space Heater
A space heater warms only a small area. Using one for each room of your home costs more than relying on a furnace. Still, this type of heater is a practical way to provide heat when you’re warming only one room. For example, you can use it to heat your bedroom while you sleep.
Should a heat pump fan be on auto or on?
Setting the fan on auto is more energy-efficient than using the on mode. In the auto mode, the fan turns on and off, depending on your thermostat’s setting. So it runs only when the pump is in use.
Why you shouldn’t get a heat pump?
Although using heat pumps can help in saving money on your utility expenses, they’re not always the more practical options to heat your home. For one, they have a high upfront cost. Some types may also require a complicated installation process.
Should a heat pump be in the sun?
Pumps benefit more from having adequate airflow than being under direct sunlight. An air-source heat pump, for example, can overheat if it’s placed in full sun.
Do Heat Pumps Stop Working When it’s Very Cold Outside?
Yes, they do, but it has to be extremely cold for them to stop running. Different models are rated for how cold it has to be before their efficiency drops to the point where they’re no longer effective. This means that the pump’s output starts dropping as it gets colder. When the output decreases, the pump has to work harder to maintain your home’s temperature at a comfortable level. As a result, it uses more electricity.
Can Heat Pumps be the Sole Source of Heat?
Areas with warmer climates can rely on heat pumps as the sole source of heat. But for regions in the country that experience freezing weather, having a primary or backup heat source will be a wise move. Heat pumps may have trouble recovering from heat loss when the temperature stays low for long periods. This spells trouble for homes that have no other heating methods in place.
Heat pumps are practical and energy-saving alternatives to traditional heating methods, such as a furnace. Because they can also serve as cooling devices, you won’t have to purchase two systems to keep your home’s temperature at a comfortable level all year round.
Still, heat pumps also have limitations and disadvantages. They can lose their effectiveness when the temperature drops to sub-zero levels. This makes it necessary to have a backup heat source if you live in areas that have freezing winters.