HVAC Repair and Replacement Guide

The common parts of an HVAC system include thermostat for temperature control, AC unit (central AC, furnace, or heat pump), duct work, compressor, evaporator coil, and exhaust outlets. We discuss them briefly below:

• Thermostat: This is the most interactive part of the entire HVAC system. It controls the heating and cooling devices by switching them on or off, or by regulating the airflow to maintain the desired temperature.
• Central Air Conditioners: Air conditioners distribute cool air throughout your home using a circuit or series of connected ducts. Central air conditioner is most common in warmer climate regions.
• Furnace: There are various types of furnaces, with the most common using gas combustion or electric resistance heat strips to produce the necessary heat. Since furnace installation can only produce heat, it is sometimes retrofitted with a central air conditioner to provide cool air during the summer months.
• Heat Pump: A heat pump is a variation of a central air conditioner. Heat pumps are capable of delivering both heated and cooled air. They work by transferring the inside heat outside during the summer months to cool the home and extracting heat from outside air or ground inside during the winter months. Heat pump systems are one of the most energy-efficient systems available today.
• Air Return: Air return is the starting point of your ventilation. Its main purpose is to suck the air along with its pollutants and contaminants from the environment through filters to be cooled or heated. This also helps to maintain air quality and airflow.
• Exhaust Outlets: Exhaust outlets are used to remove heat and gas from the environment, which can be done through chimney flue or vent stack.
• Ducts: Air ducts help to distribute heated and cooled airflow to maintain acceptable indoor quality of air. 
• Compressor: An air compressor part of the outside AC unit that helps to turn the warm refrigerant gas into liquid. It is in this compressor the heat is removed from the gas with the help of pressure.
• Evaporator Coil: Inside an AC unit, evaporator coils help cool down the air being circulated using a liquid refrigerant. A blower assembly — fan and motor — provides the necessary circulation to distribute the conditioned air.

The square footage area of your home is the top factor to determine the size of HVAC unit needed for your home. The size is calculated in tons based on how many BTUs you need to cool/heat your home. For example, for a 2000 sq. ft. home, you will need an AC unit size of 40,000 BTUs, or approximately 3.5 tons.

To find the ideal size for your home, consider these factors:

• Square Footage: This is a general guideline, not the only factor.
• Climate: Hotter climates need a larger capacity than mild ones.
• Insulation: Well-insulated homes require less BTU (British Thermal Units) for heating and cooling.
• Sun Exposure: South-facing windows let in more heat, requiring a larger system.
• Ductwork: Leaky or poorly designed ducts can reduce efficiency.

Use our AC size calculator to estimate the BTU requirements based on square footage. The calculators use a range of 20 BTU per square foot as a rule of thumb.

The following chart is an estimation for tonnage coverage based on the square footage of your property to show standard AC sizes available in the market.

By changing or upgrading your air filters to high-efficiency filters like a MERV 13 or 14, you can improve the air quality of your house. While standard filters can only capture larger dust particles, upgrading can significantly improve particle removal, including allergens like pollen and pet dander.

Some HVAC systems allow for additional filtration options like HEPA filters or UV germicidal lights. HEPA filters capture even tinier particles down to 0.3 microns, while UV lights help kill bacteria, mold, and viruses within the system.

The best HVAC system for your home will depend on a number of factors, including the size of your home, the climate in your area, and your budget. Here are some things to consider when choosing an HVAC system:

• The Size of Your Home: You will need an HVAC system that is sized correctly for your home. A system that is too small will not be able to adequately heat or cool your home, while a system that is too large will be less efficient.
• The Climate in Your Area: If you live in a cold climate, you will need an HVAC system that is good at heating. If you live in a warm climate, you will need an HVAC system that is good at cooling.
• Your Budget: HVAC systems can range in price from a few thousand dollars to tens of thousands of dollars. It is important to choose a system that fits your budget.

A ductless HVAC system, or mini split unit is beneficial for some homes based on certain needs for your household. A ductless system has multiple indoor units located in each room that you would like to have controlled heating and cooling. The mini split units are mounted on your home’s walls and connect to a compressor located outside of the home. Mini split units are easier to install than a central AC system but usually cost more upfront.

Some reasons you may be interested in a duct free AC unit would include:

• You want to cool or heat only one particular room, such as a garage or a new room that was added to the house.
• You do not use all of the rooms in your home and you would like to be energy efficient with your air conditioning use for only rooms you utilize.
• You prefer independent control of room temperature across multiple areas of your home.

Pros and Cons of Ductless AC – Mini Split System

Pro: They have lower energy costs than most of the split systems, and it is your best high-energy efficiency option. The biggest pro is that you don’t have to worry about ducts because they are ductless, so no extra infrastructure is needed.

Con: These systems are low heat effective, so if you live in cold climatic areas, getting an effective mini split system will be impractical and costly as mini split systems are costlier than traditional ones. Also, maintenance can be expensive in some areas as it is hard to get parts for the system. Consult with your HVAC contractor to know which would be the best option for you.

The most common type of HVAC system is the heating & cooling split system. Split HVAC units have two main systems, one dedicated to cooling your home and one dedicated to heating your home. They usually contain one indoor unit such as a furnace (found in a garage, utility closet, crawl space, garage, attic, or basement) and one outdoor unit such as a central air conditioner often located outside on a flat cement foundation called an AC pad.

The split systems can be configured in different ways according to the needs,

AC and Furnace: These systems are very popular and are also called forced air systems because they use blower fans in the furnace to circulate the air through ducts. They absorb untreated air and push treated air into the environment.

Heat Pump and Air Handler: Heat pump split systems are usually ideal for warm climate regions which do not experience freezing temperatures. The heat pump does not generate heat (instead absorbs ambient heat), so it is energy efficient. So the absorbed heat is circulated through the air handler via ducts. The heat pump’s function is reserved to distribute cold air in mild warm climates.

Pros and Cons of Split System

Pro: They are quite popular, efficient, and cost-effective HVAC systems. It is easy to replace the existing duct system without doing minor or no modifications. They are highly energy efficient in areas that require less heating or cooling.

Con: The forced air system may disperse dust and allergens around your home, and it might also disperse your kitchen odor to the parts of your home. The system also requires ductwork, which may be expensive for homeowners.

An air conditioner is designed solely for cooling by removing heat from the indoor air and expelling it outside. It’s best suited for hot climates and must be paired with a separate heating system, like a furnace, for colder weather. Air conditioners are ideal when cooling is the primary need, and they operate efficiently in warm environments. See how central air conditioners work.

A heat pump, on the other hand, can both cool and heat a home by reversing its operation to extract heat from the outside air and transfer it indoors. This makes it versatile and efficient in moderate climates, though its efficiency can drop in extremely cold weather. Modern heat pumps, especially cold-climate models, are better suited to handle lower temperatures compared to traditional heat pumps. See how heat pumps work.

Some of the best air conditioning brands to consider are Carrier, Trane, Lennox, American Standard, and Rheem. These brands are known for their reliability, efficiency, and performance across different models and price ranges.

Use our guide to top 10 best air conditioner brands where we compare brands based on cost of installation, AC unit efficiency, features, performance, warranties and customer satisfaction.