AC Maintenance Checklist

What Is A Heat Pump?

So, what is a heat pump? A heat pump is part of a home heating and cooling system and is installed outside your home. Like an air conditioner such as central air, it can cool your home, but it’s also capable of providing heat. In cooler months, a heat pump pulls heat from the cold outdoor air and transfers it indoors, and in warmer months, it pulls heat out of indoor air to cool your home. They are powered by electricity and transfer heat using refrigerant to provide comfort all year round. Because they handle both cooling and heating, homeowners may not need to install separate systems to heat their homes. In colder climates, an electric heat strip can be added to the indoor fan coil for additional capabilities. Heat pumps do not burn fossil fuel like furnaces do, making them more environmentally friendly.

What Types Of Heat Pumps Are There?

The two most common types of heat pumps are air-source and ground-source. Air-source heat pumps transfer heat between indoor air and outdoor air, and are more popular for residential heating and cooling.

Ground-source heat pumps, sometimes called geothermal heat pumps, transfer heat between the air inside your home and the ground outside. These are more expensive to install but are typically more efficient and have a lower operating cost due to the consistency of the ground temperature throughout the year.

How Does A Heat Pump Work?

How does a heat pump work? Heat pumps transfer heat from one place to another by different air or heat sources. Air source heat pumps move heat between the air inside a home and the air outside a home, while ground source heat pumps (known as geothermal heat pumps) transfer heat between the air inside a home and the ground outside a home. We will focus on air source heat pumps, but the basic operation is the same for both.

Heat Pump Basics

Despite the name, heat pumps do not generate heat – they move heat from one place to another. A furnace creates heat that is distributed throughout a home, but a heat pump absorbs heat energy from the outside air (even in cold temperatures) and transfers it to the indoor air. When in cooling mode a heat pump and an air conditioner are functionally identical, absorbing heat from the indoor air and releasing it through the outdoor unit.

When considering which type of system is best for your home, several important factors should be considered, including the size of the home and the local climate. A local Carrier dealer has the expertise to properly evaluate your specific needs and help you make the right decision.

Where Do Heat Pumps Work Best?

Homeowners in need of a new heating or cooling system, may consider the type of climate they live in before purchasing a heat pump system. Heat pumps are more common in milder climates, where the temperature does not typically drop below freezing. In colder regions, they can also be combined with furnaces for energy-efficient heating on all but the coldest days. When the temperature outside drops too low for the heat pump to operate effectively, the system will instead use the furnace to generate heat. This kind of system is often called a dual fuel system – it is very energy efficient and cost effective.

Important Components Of A Heat Pump System

A typical air source heat pump system consists of two major components, an outdoor unit (which looks just like the outdoor unit of a split-system air conditioning system) and an indoor air handler unit. Both the indoor and outdoor unit contain various important sub-components.

Outdoor Unit & Indoor Unit

The outdoor unit contains a coil and a fan. The coil operates as either a condenser (in cooling mode) or an evaporator (in heating mode). The fan blows outside air over the coil to facilitate the heat exchange. Like the outdoor unit, the indoor unit, commonly referred to as the air handler unit, contains a coil and a fan. The coil acts as an evaporator (in cooling mode) or a condenser (in heating mode). The fan is responsible for moving air across the coil and throughout the ducts in the home.

Refrigerant & Compressor

The refrigerant is the substance that absorbs and rejects heat as it circulates throughout the heat pump system. The compressor pressurizes the refrigerant and moves it throughout the system.

Reversing Valve & Expantion Valve

The part of the heat pump system that reverses the flow of refrigerant, allowing the system to operate in the opposite direction and switch between heating and cooling. The expansion valve acts as a metering device, regulating the flow of the refrigerant as it passes through the system, allowing for a reduction of pressure and temperature of the refrigerant.

How Does A Heat Pump Cool and Heat?

Heat pumps do not create heat. They redistribute heat from the air or ground and use a refrigerant that circulates between the indoor fan coil (air handler) unit and the outdoor compressor to transfer the heat.

In cooling mode, a heat pump absorbs heat inside your home and releases it outdoors. In heating mode, the heat pump absorbs heat from the ground or outside air (even cold air) and releases it indoors.

How A Heat Pump Works - Cooling Mode

One of the most important things to understand about heat pump operation and the process of transferring heat is that heat energy naturally wants to move to areas with lower temperatures and less pressure. Heat pumps rely on this physical property, putting heat in contact with cooler, lower pressure environments so that the heat can naturally transfer. This is how a heat pump works.


Liquid refrigerant is pumped through an expansion device at the indoor coil, which is functioning as the evaporator. Air from inside the house is blown across the coils, where heat energy is absorbed by the refrigerant. The resulting cool air is blown throughout the home’s ducts. The process of absorbing the heat energy has caused the liquid refrigerant to heat up and evaporate into gas form.


The gaseous refrigerant now passes through a compressor, which pressurizes the gas. The process of pressurizing the gas causes it to heat up (a physical property of compressed gases). The hot, pressurized refrigerant moves through the system to the coil in the outdoor unit.


A fan in the outdoor unit moves outside air across the coils, which are serving as condenser coils in cooling mode. Because the air outside the home is cooler than the hot compressed gas refrigerant in the coil, heat is transferred from the refrigerant to the outside air. During this process, the refrigerant condenses back to a liquid state as it cools. The warm liquid refrigerant is pumped through the system to the expansion valve at the indoor units.


The expansion valve reduces the pressure of the warm liquid refrigerant, which cools it significantly. At this point, the refrigerant is in a cool, liquid state and ready to be pumped back to the evaporator coil in the indoor unit to begin the cycle again.

How A Heat Pump Works - Heating Mode

A Heat pump in heating mode operates just like cooling mode, except that the flow of refrigerant is reversed by the aptly named reversing valve. The flow reversal means that the heating source becomes the outside air (even when outdoor temperatures are low) and the heat energy is released inside the home. The outside coil now has the function of an evaporator, and the indoor coil now has the role of the condenser.

The physics of the process are the same. Heat energy is absorbed in the outdoor unit by cool liquid refrigerant, turning it into cold gas. Pressure is then applied to the cold gas, turning it to hot gas. The hot gas is cooled in the indoor unit by passing air, heating the air and condensing the the gas to warm liquid. The warm liquid is relieved of pressure as it enters the outdoor unit, turning it to cool liquid and renewing the cycle.

How A Heat Pump Works – Review

Heat pumps are versatile, efficient cooling and heating systems. Thanks to a reversing valve, a heat pump can change the flow of refrigerant and either heat or cool a home. Air is blown over an evaporator coil, transferring heat energy from the air to the refrigerant. That heat energy is circulated in the refrigerant to a condenser coil, where it is released as a fan blows air across the coil. Through this process, heat is pumped from one place to another.

Let Z&X Mechanical be your heating system service solution!

Z&X Mechanical has more than 30 years of expertise in serving clients in Cyprus. Our experienced professionals understand the importance of always meeting the needs of clients while providing top – quality pool services. We will always do what we promise and ensure that you are satisfied with our heating services.

Are you interested in our services? Want to know more from our specialist? Leave us your contact below and we will contact you.

    * We collect, store and use the information you place on this form for the exclusive purpose of communicating with us for your best service, in accordance with the Company's Privacy Policy. Your data is NOT sent to third parties.

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    The Ultimate Spring HVAC Maintenance Checklist

    The arrival of spring is the perfect time for homeowners to get their HVAC systems in shape. For many, it might have been months since you have given your cooling system a thought – but with the nice weather comes persistent sunshine and rising temperatures that will eventually bring on summer heat. Fortunately, by taking simple HVAC spring maintenance steps now, you can keep your unit running optimally all year long — with much less stress!

    9-Point Spring HVAC Maintenance List

    In this blog post, we will dive into the essential AC maintenance tasks you must complete to get the most out of your home’s HVAC system this season. From changing air filters to inspecting ductwork and checking refrigerant levels, you can take several proactive measures so you don’t end up sidelined by costly repairs down the road. If you are ready to tackle some HVAC challenges while ensuring maximum efficiency from your unit this spring, let’s get started!

    1. Replace Air Filters

    AC filters are one essential component of your unit that needs frequent attention. They tend to get clogged and dirty easily and directly impact the performance and effectiveness of your air conditioner. If not cleaned promptly, a dirty filter can cause restricted airflow, energy wastage, and damage to your unit.

    Hence, your HVAC spring maintenance must start with a thorough filter cleaning session. There are different types of filters; the usable ones can easily be taken out and washed with water. However, if the filters seem worn out, it is a good time to replace them.

    A rule of thumb is to clean the filters every two weeks and get a replacement bimonthly during summer when the usage is high. Consider investing in a smart AC controller if you want to take your spring maintenance game up a notch. Some advanced models will help you automatically get notified when your filters need cleaning. This is not only crucial for increasing the lifespan of your AC but also helps to improve indoor air quality.

    2. Remove Unit Covers

    If you have mastered the art of storing away your AC units in winter, they should be covered away from all the potential external threats. But now is the time to take them off! Although it might seem obvious, many people make the mistake of turning on their HVAC systems without doing so. A simple mistake like this will compromise the efficiency of your AC and can cause damage due to overheating.

    3. Clean Around AC Unit

    If you had covers on, this step would become a whole lot easier. However, if your unit was uncovered, there would definitely be debris and dirt buildup that will need clearing up. In addition, birds often like to make their nests in the units, especially when unused.

    Inspect carefully to identify any source of concern. Start by cleaning any leaves gathered around and on the top of your air conditioner’s grill. Follow up by trimming nearby bushes and shrubs while ensuring there is at least two feet of cleared land around the unit for proper functioning. If you find any potential damages that need repairs, get in touch with an HVAC technician asap!

    4. Check Air Conditioner Refrigerant Lines

    When checking these lines, look for any signs of damage, such as leaks or cracks in the pipes. They can cause refrigerant leakage, leading to a decrease in cooling efficiency. If you notice any damage to the refrigerant lines, it’s important to have them repaired or replaced by a professional HVAC technician as soon as possible.

    Adjust the refrigerant levels according to your system. Too much or too little refrigerant will reduce the efficiency of your equipment and increase your energy costs. Check the refrigerant lines to be sure they are not worn, detached, or leaking. For the best results, call an HVAC professional!

    5. Testing the Thermostat

    Testing, calibrating, and leveling your thermostat is important to ensure perfect home temperature. Here are a few things you need to monitor:

    • Check for loose connections: Look for any loose wires or connections inside the thermostat. Tighten any loose connections using a screwdriver.
    • Test the temperature sensor: Using a thermometer, check the temperature reading on your thermostat. If the reading is off by a few degrees, you may need to recalibrate the thermostat.
    • Calibrate the thermostat: Refer to the manufacturer’s instructions on how to calibrate your thermostat. Typically, you will need to adjust the temperature using a small screwdriver until the reading matches the actual room temperature.
    • Level the thermostat: Use a level to ensure that your thermostat is level. If it is not level, adjust the mounting bracket until it is.

    Once you have finished testing, calibrating, and leveling your thermostat, replace the cover and turn the power back on to your heating and cooling system.

    6. Make Your AC Smart

    This summer is the perfect time to change up your old ways and become more efficient regarding energy usage. The bills are higher than ever, but you should mend your ways to be more responsible and sustainable. In addition, heating and cooling make up almost 50% of the energy consumption expenses. Hence, it is only logical to take control of the situation and add smart air conditioning controls to the list of your HVAC spring maintenance. One of the most cost-effective methods is pairing your air conditioners with a smart AC controller or a smart thermostat. You can benefit from multiple next-gen features like smart scheduling, geofencing, Comfy Mode, and more. With these, you can ensure that your AC runs only when it needs to, turns off automatically if you ever forget to switch it off in a rush, and even takes away the hassle of manually adjusting the settings all day.

    7. Clearing the Drainage Hole

    This is an integral part of the HVAC summer maintenance routine. The drainage hole or condensate drain is responsible for removing excess moisture. If this drainage hole becomes clogged, you might encounter various issues like water leaking from inside the unit and other types of water damage. When cleaning out the drainage hole, turn off your HVAC unit. It should be located near the base of the indoor unit. Sometimes it is visible as a small hole, while it can be covered at other times. You can use a pipe cleaner or a small brush to remove any buildup. Remember to always use a gentle hand and avoid pressure to prevent damage. Next, check drainage pans and clean them with a damp cloth if they are dirty. Test the drainage by turning the HVAC system on and checking if the water flows freely through the system.

    8. Cleaning the Vents

    Cleaning the vents is an important part of HVAC spring maintenance as it helps to ensure proper airflow and efficiency. Over time, the vents of an AC can accumulate dust, dirt, and debris, reducing the air quality in your home. By cleaning the vents, you can remove these contaminants and improve indoor air quality. Furthermore, it prevents mold growth. Moisture can accumulate in the vents, promoting mold and mildew growth. By cleaning the vents regularly, you can remove any moisture and prevent mold growth.

    9. Schedule HVAC Spring Maintenance Appointment

    Spring is considered the best time to call an HVAC technician for maintenance because it is the season right before the peak summer months; here is why:

    • Prepare for summer: The summer months can be tough on HVAC systems, as they often work overtime to keep homes cool. By scheduling maintenance in the spring, you can identify and address any potential issues before the high demand of summer arrives.
    • Cost-effective: Calling a technician during peak time means paying more to solve your AC-related problems. HVAC spring maintenance will save you a few coins and prepare you ahead of time.
    • Availability of technicians: HVAC technicians are often busiest during the peak summer months, so scheduling a maintenance appointment may be more difficult. By calling in the spring, you may have options for scheduling and can avoid potential wait times or delays.

    Scheduling HVAC spring maintenance can help you avoid potential breakdowns, improve efficiency, and ensure your system is ready to handle summer demands.

    Let Z&X Mechanical be your heating system service solution!

    Z&X Mechanical has more than 30 years of expertise in serving clients in Cyprus. Our experienced professionals understand the importance of always meeting the needs of clients while providing top – quality pool services. We will always do what we promise and ensure that you are satisfied with our heating services.

    Are you interested in our services? Want to know more from our specialist? Leave us your contact below and we will contact you.

      * We collect, store and use the information you place on this form for the exclusive purpose of communicating with us for your best service, in accordance with the Company's Privacy Policy. Your data is NOT sent to third parties.

      Read more
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