Heating and Cooling Your Home with a Heat Pump

Is it worth it?

How do you know if it makes GOOD FINANCIAL sense to invest in a Home Comfort System? Use our Utility Overpayment Calculator.

Did you get an energy usage letter from MidAmerican Energy? Chances are you did… along with every other homeowner. If your furnace or air conditioner is over 10 years old, we can…

Double the Life of Your Furnace and Cut Your Energy Bills by Up to 50% with Hybrid Energy Watchdog Technology … AND Have Your Energy Company Pay for It!
  • Are you tired of opening that energy bill every month wondering why yours is higher than your neighbors?
  • Does the thought of not knowing when you will be forced to spend thousands of dollars on a new furnace or air conditioner stress you out?

Click here to learn more about Hybrid Energy Watchdog Technology

My Home Comfort Heroes are standing by to share how this technology can double the life of your furnace and cut your energy bills by up to 50% while getting your energy company to pay for it… Call 515-657-6634 right now and we’ll give you all the details.

Yours in Comfort,
Brian Leech

Hybrid Energy Watchdog Technology

Double the Life of Your Furnace and Cut Your Energy Bills by Up to 50% with Hybrid Energy Watchdog Technology… AND Have Your Energy Company Pay for It!

There is a new advancement in heating and cooling your home. It’s called a Hybrid Energy Watchdog Technology. Just like Hybrid cars, where they alternate between burning fossil fuels and using electricity to run, these Home Hybrid systems do just that. They run on the most cost effective source possible “smartly” choosing when to switch back and forth.

How is the furnace’s life extended by double?

A standard furnace runs about 2500 hours during an average Iowa winter. When your air conditioner is replaced with a heat pump the heat pump actually heats the home approximately half of those hours. This on average reduces the amount of run time each year by about 50% which in turn extends the life of the furnace by double. It’s simple mathematics.

How does it cut my energy bills by up to 50%?

Furnace efficiencies range from 50% efficient to 95% efficient. If your furnace is an 80% efficient furnace when you spend $1.00 of gas you get 80 cents worth of heat in your home. With a heat pump when you spend $1.00 worth of electricity to run the unit you can get up to $3.80 cents worth of heat in your home. This is over 350% more efficient when compared to traditional gas furnace.

How much will I save in my home?

Each home is different. The exact amount can be calculated after measuring up your windows, doors, insulation, and square footage and calculating your current energy consumption. This process is called a Manual J Load Calculation or in short, an Engineering Analysis. Mechanical engineers charge up to $300 to perform this analysis. Service Legends does this Free of charge for homeowners with the Des Moines area who want to explore their options. Call us at 515-657-6634, 24 hours a day, 7 days a week to schedule your FREE analysis or to get your specific questions answered.

What is Hybrid Energy Watchdog Technology?

This technology allows your heat pump and your existing furnace to communicate with each other and achieve the highest amount of energy savings for your home while ensuring your comfort. With gas prices and electric prices continuously fluctuating, we never know which one is going to be more expensive to heat the home with: gas or electricity? With Hybrid Energy Watchdog Technology the power to choose is put into your hands and you are no longer held hostage to fluctuating gas and electric prices. We can adjust the parameters at any time without making major equipment changes or modifications to your system. Once this technology is installed in your home you are covered for any scenario that involves the fluctuation of gas or electricity prices.

How Much Does it Cost?

For as little as $79 a month you can invest in replacing your current air conditioner with a Hybrid Heat Pump System. On average it is only a few hundred dollars more than a new air conditioner. After our comfort advisor measures up your home you will choose your options and you will know an exact to the penny price on what your investment will be and your approximate energy savings each month.

How Does the Energy Company Pay for my Hybrid Energy Watchdog Technology?

Once your analysis is complete many homeowners will realize energy savings each month that offset the monthly investment on a new Hybrid Heat Pump. With energy savings as much as 60% each month your system can be paid for utilizing your energy savings. Once your system is paid off you will reap the rewards of reduced energy costs for the life of your Hybrid Home Comfort System.

New technology can be scary…

I agree with you, new technology MUST be tested and proven before I invest in it! Heat Pump technology has been widely used in US homes since the 1970’s and many of these systems are still in service today! This technology took a great leap a few years ago when heat pump technology was combined with a traditional furnace to produce extraordinary resorts by having the two systems work together. Thus the hybrid system is born!

This could be the Last Home Comfort System you will ever buy…

This Hybrid Energy Smart System has a Lifetime Guarantee on the heart of the system, making it likely that it’s the last one you will have to invest in for your home!

For the Geeks Who Want to Know More . . . WARNING: It Gets Very Technical This Point Forward

Air to Air Heat Pump

An Air to Air Heat Pump (AAHP) is a system which transfers heat from outside to inside a building, or vice versa. An AAHP uses a refrigerant system involving a compressor and a condenser to absorb heat at one place and release it at another. It operates using the same science as a traditional central home air conditioner. They can be used as a space heater or cooler, and are sometimes called “reverse-cycle air conditioners.

In residential heating use, an AAHP absorbs heat from outside air and releases it inside the home, as hot air. The same system can often do the reverse in summer, cooling the inside of the house. When correctly specified, an AAHP can offer a full central heating solution.

Air, at any temperature above absolute zero (-460 degrees Fahrenheit) contains some heat. An air-source heat pump transfers (‘pumps’) some of this heat from one place to another, for example between the outside and inside of residence. This can provide space heating for your home. A single system can be designed to transfer heat in either direction, to heat or cool the interior of the home in winter and summer respectively. For simplicity, the description below focuses on use for interior heating.

The technology is similar to a refrigerator or freezer or air conditioning unit: the different effect is due to the physical location of the different system components. Just as the pipes on the back of a refrigerator become warm as the interior cools, so an AAHP warms the inside of a building whilst cooling the outside air.

The main components of an air-source heat pump are:

  • An outdoor heat exchanger coil, which extracts heat from ambient air
  • A compressor to pump refrigerant containing heat from outside the home to inside the home and vice versa
  • An indoor heat exchanger coil, which transfers the heat into hot air ducts

Air source heat pumps can provide fairly low cost space heating. A high efficiency heat pump can provide up to four times as much heat as an electric heater using the same energy. See Understanding Heat Pump Efficiency Ratings. In comparison to gas as a primary heat source, however, the lifetime cost of an air source heat pump may be affected by the price of electricity compared to gas (where available). Use of gas may be associated with higher carbon emissions, depending upon how the electricity is generated.

A “standard” domestic air source heat pump can extract useful heat down to about -5F or 0F. At colder outdoor temperatures the heat pump is less efficient; it could be switched off and the premises heated using only supplemental heat (also known as backup or auxiliary heat). Auxiliary heat systems should be sized to heat the entire home utilizing standard Manual J load calculations. Air source heat pumps can last for over 20 years with similar annual maintenance procedures to a standard central air conditioner. There are thousands of heat pumps from the 1970s and 1980s in Iowa that are still in service today, albeit the older models are less efficient.


Air to Air Heat Pumps are used to provide interior space heating and cooling even in colder climates. A major advantage of many AAHPs is that the same system may be used for heating in winter and cooling in summer. Though the cost of a heat pump and the installation is generally about 18% higher than a traditional air conditioner, it is far less than the cost of a ground source heat pump (or Geothermal Unit), because a ground source heat pump requires excavation to install its ground loop. The advantage of a ground source heat pump is that it has access to the thermal storage capacity of the ground which allows it to produce more heat for less electricity in cold conditions.

AAHPs are often paired with auxiliary or back up heat systems to provide backup heat when outside temperatures are too low for the pump to work efficiently. This is commonly known as a Hybrid or Dual Fuel System. Propane, natural gas, or oil furnaces can provide this supplementary heat. All-electric heat pump systems have an electric furnace or electric resistance heat, or strip heat, which typically consists of rows of electric, coils that heat up. A fan blows over the heated coils and circulates warm air throughout the home. This serves as an adequate back up heating source, but as temperatures go down, electricity costs rise, and power outages pose an even greater threat.

The outdoor section on some units may ‘frost up’ when there is sufficient moisture in the air and outdoor temperature is between 32°F to 41°F. This restricts air flow across the outdoor coil. These units employ a defrost cycle where the system switches temporarily to ‘cooling’ mode to move heat from the home to the outdoor coil to melt the ice. This requires the supplementary heater (resistance electric or gas) to activate. The defrost cycle reduces the efficiency of the heat pump during the defrost cycle, although the newer (demand) systems are more intelligent and need to defrost less. As temperatures drop below freezing the tendency for frosting of the outdoor section decreases due to reduced humidity in the air.

How Does an Air to Air Heat Pump Work?

  • The Outdoor Unit
  • An Indoor Compartment
  • Condenser Fan
  • Condenser Coil
  • Evaporator Coil
  • Indoor Blower
  • Expansion Valve
  • Compressor
  • Accumulator
  • Reversing Valve

Heating and cooling is accomplished by pumping a refrigerant through the heat pump’s indoor and outdoor coils. Like in a refrigerator, a compressor, condenser, expansion valve and evaporator are used to change states of the refrigerant between colder liquid and hotter gas states.

When the liquid refrigerant at a low temperature and low pressure passes through the outdoor heat exchanger coils, ambient heat causes the liquid to boil (change to gas or vapor): heat energy from the outside air has been absorbed and stored in the refrigerant as latent heat. The gas is then compressed using an electric pump; the compression increases the temperature of the gas.

Inside the building, the gas passes through a pressure valve into heat exchanger coils. There, the hot refrigerant gas condenses back to a liquid and transfers the stored latent heat to the indoor air, water heating or hot water system. The indoor air or heating water is pumped across the heat exchanger by an electric pump or fan.

The cool liquid refrigerant then re-enter the outdoor heat exchanger coils to begin a new cycle.

Most heat pumps can also operate in a cooling mode where the cold refrigerant is moved through the indoor coils remove the heat form the home then discharging it outside just like a conventional air conditioner.

Understanding Heat Pumps Efficiency Ratings

The ‘Efficiency’ of air source heat pumps is measured by the Coefficient of performance (COP). A COP of 3 means the heat pump produces 3 units of heat energy for every 1 unit of electricity it consumes. Within temperature ranges of -3°C to 10°C, the COP for many machines is fairly stable at 3-3.5.

In mild weather, the COP of an air source heat pump can be up to 4. However, on a very cold winter day, it takes more work to move the same amount of heat indoors than on a mild day. The heat pump’s performance is limited by the *Carnot cycle and will approach 1.0 as the outdoor-to-indoor temperature difference increases, which for most air source heat pumps happens as outdoor temperatures approach −18 °C / 0 °F. Heat pump construction that enables carbon dioxide as a refrigerant may have a COP of greater than 2 even down to -20°C, pushing the break-even figure downward to -30 °C (-22 °F). A ground source heat pump (Geothermal Unit) has comparatively less of a change in COP as outdoor temperatures change, because the ground from which they extract heat has a more constant temperature than outdoor air.

The specific design of a heat pump has a considerable impact on its efficiency. Many air source heat pumps are designed primarily as air conditioning units, mainly for use in summer temperatures. Designing a heat pump specifically for the purpose of heat exchange can attain greater COP ratings and an extended life cycle. The principal changes are in the scale and type of compressor and evaporator.

Seasonally adjusted heating and cooling efficiencies are given by the **heating seasonal performance factor (HSPF) and ***seasonal energy efficiency ratio (SEER) respectively.

Wiki Resources

*The Carnot cycle is a theoretical thermodynamic cycle proposed by Nicolas Léonard Sadi Carnot in 1823 and expanded by in the 1830s and 40s. It can be shown that it is the most efficient cycle for converting a given amount of thermal energy into work, or conversely, creating a temperature difference (e.g. refrigeration) by doing a given amount of work.

Every single thermodynamic system exists in a particular state. When a system is taken through a series of different states and finally returned to its initial state, a thermodynamic cycle is said to have occurred. In the process of going through this cycle, the system may perform work on its surroundings, thereby acting as a heat engine. A system undergoing a Carnot cycle is called a Carnot heat engine, although such a ‘perfect’ engine is only a theoretical limit and cannot be built in practice.

**HSPF (Heating Seasonal Performance Factor) is a term used in the heating and cooling industry. HSPF is specifically used to measure the efficiency of air source heat pumps.

The efficiency of air conditioners are often rated by the Heating Seasonal Performance Factor (HSPF) as defined by the Air Conditioning, Heating, and Refrigeration Institute in its standard 210/240 Performance Rating of Unitary Air-Conditioning and Air-Source Heat Pump Equipment.

The higher the HSPF rating of a unit, the more energy efficient it is. HSPF is a ratio of BTU heat output over the heating season to watt-hours of electricity used. It has units of BTU/watt-hr.

Depending on the system, an HSPF ≥ 8 can be considered high efficiency and worthy of a US Energy Tax Credit.

The HSPF is related to the non-dimensional Coefficient of Performance for a heat pump, which measures the ratio of heat energy delivered to electrical energy supplied, independently of the units used to measure energy. The HSPF can be converted to a seasonally-averaged COP by converting both the BTU heat output and the electrical input to a common energy unit (e.g. joules). Since 1 BTU = 1055 J, and 1 watt-hour = 3600 J, the seasonally-averaged COP is given by:

  • Average COP = Heat transferred / electrical energy supplied = (HSPF * 1055 J/BTU) / (3600 J/watt-hour) = 0.293 HSPF.

Thus, a system which delivers an HSPF of 7.7 will transfer 2.25 times as much heat as electricity consumed over a season. In Europe the term Seasonal Performance Factor (“SPF“) is used to mean the same as the average COP over the heating season. Thus a system which transfers 2.25 times as much heat as the electricity consumed is said to have an SPF of 2.25. A well designed ground source heat pump installation should achieve an SPF of 3.5, or over 5 if linked to a solar-assisted thermal bank.[4]

Example: For a heat pump delivering 120,000,000 BTU during the season, when consuming 15,000 kWh, the HSPF can be calculated as:

  • HSPF = 120000000 (BTU) / (1000) / 15000 (kWh)) =
  • HSPF = 8

***The efficiency of air conditioners is often rated by the Seasonal Energy Efficiency Ratio (SEER) which is defined by the Air Conditioning, Heating, and Refrigeration Institute in its 2008 standard AHRI 210/240, Performance Rating of Unitary Air-Conditioning and Air-Source Heat Pump Equipment.

The SEER rating of a unit is the cooling output during a typical cooling-season divided by the total electric energy input during the same period. The higher the unit’s SEER rating the more energy efficient it is. In the U.S., the SEER is the ratio of cooling in British thermal unit (BTU) to the energy consumed in watt-hours. The coefficient of performance (COP), a more universal dimensionless measure of efficiency, is discussed in the following section.

For example, consider a 5,000-British-thermal-unit-per-hour (1,500 W) air-conditioning unit, with a SEER of 10 BTU/W•h, operating for a total of 1000 hours during an annual cooling season (e.g., 8 hours per day for 125 days).

The annual total cooling output would be:

5000 BTU/h × 8 h/day × 125 days/year = 5,000,000 BTU/year
With a SEER of 10 BTU/W•h, the annual electrical energy usage would be about:

5,000,000 BTU/year / 10 BTU/W•h = 500,000 W•h/year
The average power usage may also be calculated more simply by:

Average power = (BTU/h) / (SEER) = 5000 / 10 = 500 W
If your electricity cost is 20¢/kW•h, then your cost per operating hour is: 0.5 kW * 20¢/kW•h = 10¢/