Heating and Cooling

Common HVAC Questions

How often should HVAC systems be serviced?

HVAC systems should be inspected by a professional contractor just before the heating or cooling season. It will prevent the system from any damage and allow to maintain the proper work of HVAC devices.

Does the outdoor unit have to be checked from time to time?

It is important to check the outdoor unit every few weeks to remove leaves, debris, and other small things around the unit. Even small and lightweight things can block the airflow or damage the HVAC device.

What are the air ducts, and how do they affect airflow?

Air ducts are canals that transport the medium in the building (hot and cold air). Ducts have to be professionally cleaned, montaged and well insulated. Any leaks may influence the air quality or system efficiency. A properly installed system can improve efficiency by up to 30%.

Is it worth installing a thermostat, and how do I set it up?

Installing a thermostat is an easy way to save money spent on bills. It will stop your HVAC system from running on overdrive. Most thermostats have a manual to help you set up all the settings.

How often should HVAC filters be replaced?

Replacing HVAC filters depends on the model of the filter, which can be found in the installation manual. It is recommended to replace the filter every season (3-4 months) when the filter is dusty or has changed its color. Replacing filters can improve the quality of the air and the performance of the system.

What maintenance can I do myself?

Usually, you can do some basic things like replacing the filters or cleaning.

How can the HVAC system efficiency and lifespan be improved?

There is a simple solution for improvement. Your system has to be regularly checked by a professional contractor. Cleaning and maintenance of the performance of the system will increase the lifespan and efficiency of the system.

How do I know if my HVAC system is operating safely?

Installing additional devices like fire and carbon monoxide detectors will improve the safety in your home and help you monitor the safety.


10 Interesting facts about HVAC systems

HVAC facts
  1. The invention of the air conditioning system improved the air quality in closed places. As a result, diseases were cured, and less people suffered from illnesses like asthma.
  2. The first man who built the air conditioning system was Willis Carrier in 1902. Now his company Carrier Corporation is the world leader in the HVAC sector.
  3. The annual energy used for air conditioning by the US is the same as the whole continent of Africa's annual energy usage for all power needs.
  4. The lifetime of properly maintained and installed HVAC systems is estimated to be 10 to 15 years, depending on the manufacturer of the product.
  5. Research shows that the invention of AC has reduced the human’s natural tolerance changes in extreme heat. Now people are used to temperatures up to 90 °F. Above this temperature, people feel uncomfortable.
  6. The first building with an air conditioning system installed was the New York Stock Exchange.
  7. Many commercial and government offices took two-month vacations during summer before air conditioning was popular and known. The phrase “summer break” can relate to that fact.
  8. Air conditioners reduce home air humidity. Homes that have moist air feel warmer than buildings where the level of humidity is low.
  9. The average family spends more than 2000$ on their bills annually. More than half of these bills are related to heating and cooling systems.
  10. Installing a programmable controller with a thermostat can reduce the heating and cooling bills by 10 %.


How home AC system works?

Air Condition Systems which are installed in the home have a simple working pattern. Mainly air conditioners provide cold air inside the building or can heat the air in some closed spaces (heating mode).

How do AC systems work?

All these systems use a special chemical fluid which is called refrigerant. Moreover, each AC system has three main components:

  • Compressor
  • Condenser Coil
  • Evaporator Coil

A compressor is a device that raises the gas pressure in the system by reducing its volume. Condenser and evaporator coils are the heat exchangers, parts of the system which are associated with heat transfer. They play an essential role in the refrigerant transfer process.

These components work together and change the phase of the refrigerant from gas to liquid and back again. The compressor raises the system pressure before the refrigerant enters the condenser coil, where it is converted to liquid. The phase change allows heat to be absorbed or released into the surrounding area. After, it is transferred to the evaporator coil. In this part, heat from enclosed spaces, such as rooms or offices, is absorbed by the refrigerant. The refrigerant then stores the heat, which can be easily transported. The heat is released to the outside when the refrigerant returns to its liquid phase. This process is usually called a refrigeration cycle. The air conditioning unit runs and repeats this cycle as long as it reaches the desired room temperature set on the thermostat.

how do ac systems work


HVAC Common Terms

Air Changer per Hour (ACH) - how many times the air is changed in the room per hour using ventilation systems.

BTU (British Thermal Unit) - a measurement of heat used in HVAC systems. The amount of energy needed to raise the temperature of one pound of pure water by one degree Fahrenheit.

Chiller - an appliance that removes heat from the liquid phase. This is done through vapor-compression or refrigeration cycles. The cooled fluid from this process passes through air condition systems reducing the air temperature. This device is the main component of HVAC systems.

Ductwork - special channels and pipes that are used in AC and HVAC systems for airflow.


Dehumidifier - an appliance that reduces the level of humidity in the air.

Heat Pump - a simple device designed to absorb heat from a colder space and release it to warmer places.

heat pump

Split Zone Air Conditioner - a type of air conditioning system. These systems have two separate units, an outdoor and an indoor unit. The condenser is located in the outdoor unit, and the evaporator is located in the indoor unit. Both units are connected with a lineset or pipe filled with the refrigerant.

Indoor Unit
indoor unit
Outdoor Unit
outdoor unit

Thermostat - a device that controls and regulates the systems. This device allows you to easily set the optimal temperature inside your home.


Refrigerant - is a fluid that is used in the refrigeration cycle in some popular devices like air condition systems or heat pumps. These substances mainly transfer the heat by changing phases from liquid to gas in HVAC devices. Examples of popular refrigerants are R410a, R134a, R-717, and R-290.


Central Air Conditioner

A Central Air Conditioner (AC) is a type of heating and cooling system. The main characteristic of a central AC is that all of its components (heat exchanger, fan, blower, compressor, evaporator coil, and condenser coil) are packed into one cabinet. Typically, a central AC is mounted outside a building on the roof or ground. The return and supply ducts run through the walls and enter the interior of the Central AC. These all-in-one kits sometimes include electric heating coils or natural gas furnaces. The additional components eliminate the need to mount additional heating inside your building.

central ac
central ac


How does HVAC size affect energy efficiency?

HVAC systems have to be the right size to maintain the optimal performance of the whole system. Usually, these systems can run at peak efficiency. However, the HVAC energy efficiency you obtain is dependent on choosing the right size of the HVAC system. Choosing the rights size HVAC system allows you to avoid paying higher energy and temperature fluctuations.

We can imagine two situations where the HVAC system is too small and too big. If your HVAC system is too small, your system will work repeatedly to cool or heat your home at the set temperature. In this case, your energy bill will increase. If your HVAC system is too big, the system will be working unequally in a short period. For example, it will turn on and off every 15 minutes. This performance may lead to some trouble with the system or may lead to damage.

Due to the issues with wrong HVAC sizing, installers and users need to keep in mind factors that influence HVAC sizing. These factors include:

  • The climate in the region where the HVAC system is going to be installed
  • Walls materials – bricks, concrete or other - these materials have different thermal transmittance
  • The R-value of insulation
  • Number of windows and doors in the building
  • Use of appliances that generate some heat like an oven
  • Building location – How much building area is shaded or light during the day

These factors all have an influence on the size of HVAC you may need. Installers and users need to calculate the optimal size of systems to prevent losing efficiency. The systems can not be too large or too small. HVAC system size has to be just right depending on all these factors. To find out what size HVAC system you need to maximize energy efficiency, sign up with us and we will help you out!

hvac size


What is HVAC?

Heating - Systems/equipment or devices which raise the temperature inside rooms.

Ventilation - The air circulation process between outdoor and indoor air. This process can work without any devices (gravitational ventilation) or with some extra devices electricity-powered (mechanical ventilation).

Air Conditioning - Air conditioning is a process to create and maintain certain temperature, relative humidity and air purity conditions in indoor spaces.

HVAC is an acronym for heating, ventilation and air conditioning systems. These systems maintain the optimal temperature in residential and commercial buildings. They ensure that the temperature inside buildings is just right.



What affects HVAC energy efficiency?

What is AC energy efficiency?

First of all, let’s look at how efficiency is describe when we talk about HVAC efficiency. Usually, there are two definitions to describe HVAC efficiency:

  • Energy Efficient Ratio (EER) measures how efficiently a room air conditioner will operate at a specific outdoor temperature. The higher the EER, the more efficient the system.
  • Seasonal Energy Efficiency Ratio (SEER) measures how efficiently a central air conditioner will operate at a specific outdoor temperature. The higher the SEER, the more efficient the system.

Obviously, high-efficiency cooling and heating systems have an advantage over lower-efficiency models. Higher efficiency means your system can achieve and maintain the desired temperature in your house which also leads to lower operating costs of the running device. In general, new air conditioners with higher EERs or SEERs have higher price tags. However, the higher initial cost of an energy-efficient model will be recovered several times during its lifespan.

Main factors that can lower efficiency

Size of the system

HVAC units need to be appropriately adjusted to space, which has to be heated or cooled. An air conditioner that is too small for this space will continually struggle to meet temperature demands. This struggle will lead to more energy usage, higher utility bills and ultimately early system failures. On the other hand, oversized AC will cool the home quickly but not necessarily evenly. It will also cycle on and off repeatedly and ultimately waste energy.

Age of the units

The average life span of an HVAC system is between 10 to 15 years. If it is older than 10 years, it is very likely that it's using too much energy. Therefore it is recommended to have an older unit inspected by a professional to determine its level of HVAC efficiency.

Energy consumption of system components

An HVAC system can be divided into a few major parts: Fan, cooling, heating component, compressor. Usually, the majority of energy consumption of HVAC is taken by the fan (34%). Therefore, it will influence the efficiency the most. Typically there are two fan setting options when you run your HVAC system –manual and automatic. It is recommended to switch to the automatic fan setting so the fan only turns on when the unit does, to disperse warm or cool air throughout your home. It is important to reduce overall energy use and increase energy efficiency while delivering a comfortable environment.

Air quality and system contamination

Among other things, the operation of an HVAC system is dependent on its capacity to filter. The air conditioning's function is, among other tasks, to remove and filter the air of dust, pollen, cat hair and other fine, unwanted air impurities. When things move into the HVAC system’s air filters, the system begins to work harder and becomes less energy-efficient. Hence, make sure you replace your filters and provide maintenance regularly.

HVAC system type

As already mentioned, matching the system to the space requirements is one of the key issues in terms of system efficiency. It is worth noting here the type of system you can have in your home which is a multi-split or simply split. We recommend reading about the differences between these systems and when to choose the best one in our article 'Multi Split AC' dedicated to this topic.


When To Replace Your HVAC System?

HVAC systems allow us to quickly identify whether they are functioning properly or not. If you find that they are not functioning properly, you don't always have to replace the entire system right away. An HVAC system is divided into 3 parts: an outdoor unit, an indoor unit, and ducting that connects these units. So it's a good idea to first find out exactly where the cause of the problem lies. However, sometimes even if you do find where the problem lies, you will still need to replace your HVAC system. In this article, you will learn when it is time to replace your system and when it is worth repairing it.

When to fix your HVAC system?

If your system has less than 10 years

The National Association of Home Builders estimates that the average lifespan of an HVAC system should be between 10 and 15 years. It is possible that your system has broken down but it will most likely be a minor repair.

If your system is regularly maintained

There are many components in your HVAC system that need to undergo regular maintenance or replacement. Examples include filters that trap dust, fungus, mould, and even cigarette smoke. So it's a good idea to have your system serviced frequently in the fall and spring.

If you are uncertain whether your wires are working properly

As mentioned before, the indoor and outdoor units are connected by wires, and they may be the reason for ineffective maintenance of the desired temperature in the room. Investing in a professional duct inspection and sealing any gaps for about $50 can make your HVAC run more efficiently with a relatively inexpensive repair.

When to replace your HVAC system?

If your system has more than 10 years

HVAC systems can last up to 10 - 15 years. Everything depends on how you take care of your system in the first place. An average cost of a new unit typically is in the range between $5000 and $8500. This is not a small investment, of course, but it also means a new, more efficient unit.

If your energy costs are increasing

Your electric bill will obviously change from month to month during the year. However, if the efficiency of your system starts to decrease, you will definitely notice a difference in your energy costs. A less efficient system means your HVAC is working overtime to heat and cool your home, which means it costs more. Therefore, it might be better to just replace the system at some point.

If the temperature in your house cannot be maintained at a certain level

If you can feel that the temperature in your household rooms is different from your normal temperature set up or if you have to regulate your device much more than you are used to, then you may have to replace your HVAC  system. Another sign to replace your HVAC system is if your unit needs to run during the day and night to keep the desired temperature.

If your outdoor unit is exceptionally noisy

The outdoor unit is doing most of the work in your HVAC system. A new unit or a well-maintained one runs quietly. If it starts becoming noisy, it is recommended to have your device serviced. However, in most cases, it means it is time to replace your system.

Your home gets dusty easily

The role of the HVAC system besides heating and cooling is also keeping constant ventilation. It does this by removing dust and dirt from your home. If you see that there is more dust in your home after a relatively short amount of time, it might also mean your system is not efficient anymore and needs replacement

So what to do?

It is quite simple! At the end of the day, we want to do what is more cost-effective, right? We recommend estimating the costs of fixing your HVAC system and multiplying that by the number of years your system already has. After, you may want to compare the obtained amount with the price of the new unit. If preparing your HVAC system costs more than installing a new one, then replace it.