HVAC Blog | National Air Warehouse

As a home builder, choosing the right air conditioner can make or break the success of your project. If you make the right choice, you can ensure an optimal climate for the home without busting the homeowner’s wallet. With the wrong air conditioner, the new house might remain uncomfortably warm, even when the AC system is running at full capacity, and and it can significantly increase the homeowner’s energy bills.

Some of the aspects of air conditioning systems that home builders have to consider include heating capacity, cooling capacity, cooling efficiency, heating efficiency, air flow orientation, price, and brand. Read on to learn more about choosing a system with the right heating capacity for your project.

Understanding Heating Capacity Measurements

For HVAC equipment, heating capacity is measured in British Thermal Units (BTUs). Formally, one BTU is defined as the amount of energy that is required to raise the temperature of one pound of water by one degree Fahrenheit. In the context of an air conditioner, the heating capacity is the amount of energy that it takes to remove a certain amount of heat from the surrounding air. For air conditioners than are intended for entire homes and buildings (rather than single rooms), you will typically see BTUs ranging from about 40,000 to over 115,000.

Factors Affecting Air Conditioner Heating Capacity Needs

At the most basic level, the number of BTUs you need the air conditioner to have depends on the size of the home you are building. Put simply, a larger home needs an air conditioner with a higher heating capacity. However, there are also other factors that can affect the needs of the home. These include:

• Window type, size, and location. Windows affect the amount of sun the home gets in the summer, which in turn impacts the amount of heat that must be removed from the air by the AC system.
• Insulation type and quality. If the home has excellent insulation, you may be able to get away with an air conditioner with a lower heating capacity.
• Height of the ceilings. The height of the ceilings affects the overall amount of heat that must be removed from each individual room, and it also impacts how much heat is retained within each room.
• Location of the home. If the home is located in a cool climate, the necessary heating capacity for the AC system is lower than it would be for a house of the same size in a warmer climate.

At National Air Warehouse, homebuilders can find air conditioning systems that work for any project. Contact us today for more information!

During the dog days of summer, there is nothing worse than an air conditioning system malfunction in your home or business -- especially if you are unable to determine the cause. Immediately jumping to the conclusion that you need to replace your whole air conditioning unit can be a costly mistake, but it can also be very expensive to hire an expert to identify an easily diagnosable problem. When your air conditioner stops working, one of the simplest things to check for is a malfunctioning condenser fan motor.

The Importance of the Condenser Fan Motor

In an air conditioning system, heat from the surrounding air is absorbed by a refrigerant, creating cool air that can be circulated throughout your home or business. The condenser is the part of the system that releases the heat that has been absorbed by the refrigerant during the cooling process, which gets the system ready for the next cooling cycle. As the refrigerant releases the heat, the condenser fan blows the heat past the condenser coil so that the heat can be released. The condenser fan motor is the driver of the condenser fan, so it is essential for the proper functioning of your air conditioning system.

Diagnosing Problems with Your Condenser Fan Motor

A telltale sign that your condenser fan motor might not be working is a situation in which your air conditioning seems to work for awhile, but then stops working. When you initially turn on the air conditioning unit, it will blow cold air into your home or office, but a short time later, the unit will just start blowing out room temperature air.

To further investigate the situation, you can turn the system on and monitor the condenser fan. If the condenser fan does not start spinning within 20 minutes, it is likely that there is a problem with the condenser fan motor. There is a chance that the problem is mechanical -- that is, a stuck fan -- so you can try to get it spinning again by nudging it with a small stick. However, if this does not work, you probably need to replace your condenser fan motor.

Replacing Your Condenser Fan Motor

Luckily, most condenser fan motors are not extremely expensive. You can buy a high quality condenser fan motor for $175 to $200, which is much less than purchasing an entirely new air conditioning unit. National Air Warehouse offers top-notch condenser fan motors at competitive prices. Contact us today to find a motor that works for your system!

If you are a home remodeler, you might find yourself needing to replace the ducts in existing HVAC systems. Whether the duct is in an attic, a basement, or a crawlspace, the wear-and-tear of long-term usage can damage the duct, resulting in leaks that cause air to escape before it can be released into the home. In many cases, ducting needs to be replaced as part of a larger home remodel, in order to ensure that a comfortable climate can be maintained in all rooms of the house.

While the ductwork in an older home may be uninsulated, most of the replacement ducts on the market today are insulated. When you consider the options, you will find that different ducts have different insulation ratings, which are expressed as R-values. You need to understand what the R-value means in order to choose the right one for your home remodeling project.

Thermal Resistance (R-Value) Definition

The United States Department of Energy defines thermal resistance, also known as R-value, as “the insulating material’s resistance to conductive heat flow.” Put more simply, the R-value measures the effectiveness of the insulation material. A material with a higher R-value is a better insulator. Some of the factors that influence R-value include the composition of the insulation material, the thickness of the material, and its density.

The Right R-Value for a Home Remodeling Project

When deciding how high the R-value needs to be for the home remodeling project that you are currently working on, the two main things you need to consider are the climate zone in which you are working and the location of the ducting within the home.

• For homes that are located in a COLD CLIMATE, a high R-value is extremely important. If the ducting is located in an attic, the R-value should be between R6 and R11. For ducting located in a crawlspace or unheated basement, anywhere from R2 to R11 will probably suffice.
• For homes that are located in a MIXED CLIMATE, a high R-value is slightly less important, but it can help to save the homeowner money during the colder months. If the ducting is located in an attic, an R-value between R4 and R8 is sufficient. The range expands if the ducting is located in a crawlspace or unheated basement; anywhere from R2 to R8 will probably work.
• For homes that are located in a WARM CLIMATE, you should still be looking for replacement ducts with R-values between R4 and R8 if the ducting is located in the attic. If the ducting is located in a crawlspace or unheated basement, you can probably get away with no insulation at all, but to be on the safe side and help save the homeowner money, most home remodelers choose ducting with an R2 or R4 value.

If you’re looking to purchase ducting for your home remodeling project, National Air Warehouse offers options with R-values ranging from R4 to R8. Contact us today for more information about our products!

When looking for a new furnace, you’ll probably notice different options have different AFUE ratings. AFUE (which may be pronounced as “A-Few” or “A-F-U-E”) stands for Annual Fuel Utilization Efficiency. Essentially, it is a measure of the efficiency with which the furnace operates. Therefore, it essential to consider the AFUE rating when you purchase a new furnace.

Calculating the AFUE Rating

The Federal Trade Commission requires all new furnaces and boilers in the United States to display their AFUE rating to consumers. Like SEER ratings for air conditioning systems, the AFUE rating indicates the level of efficiency with which your system operates. However, unlike the SEER rating system, which utilizes an arbitrary rating scale, the AFUE rating coincides with the direct calculation of the ratio of the annual heat output of the furnace to the total amount of energy consumed by the furnace. Put more simply, it is the amount of heat produced per unit of energy consumed.

AFUE = (Total heat output) / (Total energy consumed)

When you perform this calculation, you will come up with a percentage -- which is your AFUE rating. If your AFUE rating is 85%, then 85% of the fuel you put in your furnace will be converted into usable heat. The other 15% will be lost to air leaks, burners, and other sources of inefficiency. However, it is important to note that heat losses in the duct system and piping are not included in the AFUE rating. According the the U.S. Department of Energy, additional energy losses can be as high as 35% if your ducts are located in an attic, garage, or other unconditioned area.

What to Expect from an AFUE Rating

For old, low efficiency heating systems, the AFUE is usually between 56% and 70%. A heating system is considered to have medium-level efficiency if the AFUE rating is between 80% and 83%. To be considered a high efficiency heating system, a furnace must have an AFUE rating that is between 90% and 98.5%. Choosing a higher efficiency system with a higher AFUE rating will help you save both energy and money.

An Important Caveat: AFUE Ratings and Fuel Type

When it comes to energy cost comparisons, AFUE ratings can only be directly compared if you are looking at systems that utilize the same fuel type. For example, natural gas furnaces can vary widely in AFUE rating, while all electric furnaces have AFUE ratings between 95% and 100%, since there are basically no sources of energy loss -- but that doesn’t mean that choosing the electric furnace will yield lower energy costs. Electricity costs more than natural gas in most parts of the country, so a gas furnace with a slightly lower AFUE rating will probably save you money in the long run.

National Air Warehouse offers a wide range of medium- and high-efficiency gas furnaces. Contact us today to find the right system for your home or business!

Evaporator coils are essential to the proper functioning of your air conditioning unit, ensuring an optimal climate in your home or business. Just as the electrical coils that comprise heat strips warm the air that comes out of your heater, evaporator coils cool and condition the air that is released from your air conditioner. Your air conditioner works by drawing in surrounding air from your home. When the air passes over the evaporator coils, the heat is removed. The evaporator coils also work in conjunction with the condenser unit to condense the water in the air, thereby reducing the humidity. That way, the air that is released into your home or business is cool and dry, optimizing the climate during the dog days of summer.

There are several types of evaporator coils on the market today. Cased evaporator coils are the most common, with several different subtypes available, but you can also find uncased coils that can meet your unique needs.

Cased Evaporator Coils

The air conditioning units in most homes and businesses are equipped with cased evaporator coils. Cased evaporator coils are particularly popular because they are highly durable and because they are relatively easy to install. Within this category of evaporator coils, there are three common subtypes:

• A Coils. A Coils are named for the shape that they take within the case, which resembles a capital letter “A.” They are most commonly used in vertical air conditioners, in which the air flows either up or down as it pases through the coils. A Coils can accommodate enough refrigerant to operate at a relatively high efficiency.

• N Coils. Like A Coils, N Coils get their name from the shape of the coils within the case, which resembles a capital letter “N.” They can work for either vertical air conditioners or for horizontal air conditioners, in which the air flows in one side of the unit and out the other. It is important to note that N coils are growing in popularity because they are smaller than the other options and because they operate at a higher level of energy efficiency.

• Slab Coils. Slab coils are the least common type of coils on the market. They are usually used for horizontal air conditioning units.

Uncased Evaporator Coils

Uncased evaporator coils can work for either vertical or horizontal air conditioning units. They are ideal for systems that require customization because their is no outer casing. As a result, the shape of the coils can be easily maneuvered in an ideal position. However, it is important to note that after you purchase an uncased evaporator coil, you may need an expert technician to help you customize the shape to fit your unit.

National Air Warehouse offers a variety of cased evaporator coils, and we can also help you find uncased options that can be customized to your individual needs. Contact us today for more information about our products!

If you are thinking about installing a heat pump system in your home or business, you might be considering a gas split system -- the most common type of heat pump system on the market today. A gas split system consists of an outdoor heat pump condenser and an indoor handler that is usually stored in your basement or attic. While there are a variety of decisions you will have to make when choosing a gas split system, one important question is whether or not you want to include optional heat strips in your system.

How Heat Strips Work

Heat strips provide supplemental heat during unexpectedly cold periods, when your regular heat pump system cannot adequately warm your home or office. To understand how heat strips work, it can be helpful to know how the heat pump operates under normal conditions. The heat pump pulls in air from the surroundings, and the liquid refrigerant captures the heat in the air. This causes the refrigerant to be converted into a warm vapor, making it possible for the heat to be dispersed throughout the building.

However, when the outside temperature drops below 40 degrees, there is very little heat for your heat pump to use, and the heat pump system is unable to draw in enough warm air to sufficiently heat the building. That’s where heat strips come in. Heat strips are strips of electric heating coils, consisting of wire elements that can be heated using electricity. When air flows over the heat strips, it is warmed before being distributed throughout your home or business.

Choosing a Gas Split System with Heat Strips

When choosing a gas split system, you will have to decide whether you want to buy a traditional system or a complete system that includes supplemental heating via heat strips. It might be a good idea to choose a gas split system that includes heat strips if you live in a location that is prone to low temperatures and sudden cold snaps in the winter.

Some buyers shy away from heat strips because the heat pump system operates less efficiently when they are in use. You might worry that heat strips will start working when supplemental heat isn’t actually needed, unnecessarily driving up your energy bill. However, there are certain things you can do to prevent this from happening -- like keeping your thermostat set at a constant temperature, gradually increasing the temperature on your thermostat when it does need to be raised, and avoiding the emergency heat setting. If you follow those procedures, you can avoid unnecessary energy expense, but still have optional heat strips available to provide supplemental heat when you need it.

National Air Warehouse offers a wide variety of gas split systems, including our featured Rheem Gas Split Systems, some of which include optional supplemental heating via heat strips. Contact us today for more help choosing the gas split system that is best for you!

When you look for a new thermostat for your home or business, you are often faced with a dizzying array of choices. The many thermostats on the market today have a wide range of capabilities, so it can be challenging to figure out which one best meets your needs. The first decision that you need to make in the thermostat purchasing process is whether you want a programmable thermostat or a non-programmable thermostat.

Programmable Thermostats

Programmable thermostats are becoming increasingly popular for controlling the heating and cooling systems in homes and businesses. With a programmable thermostat, you can set the temperature in advance. That way, you can coordinate your heating and cooling needs with your schedule. For instance, if you work a 9-to-5 job in the summer , you might set the thermostat so that the air conditioner doesn’t waste energy running all day long, but it turns on just soon enough that you come home to a cool kitchen. Similarly, in a small business, you can set your heating and cooling system so that it ensures a comfortable environment during working hours, but doesn’t cut into your budget by running at night.

A programmable thermostat can be especially helpful if you live in a place where there is a large temperature swing at night. You don’t want your air conditioner running when the temperature drops to 55 degrees in the early morning, but if you know that it will be 85 degrees by 3pm, you can set the thermostat to keep the building cool in the afternoon.

In fact, according to Energy Star, you shouldn't set your thermostat to one temperature and just leave it there. By setting your thermostat to different temperatures according to the time of day or season, you will maintain home comfort, save energy, and also save on air conditioning and heating costs. The infographic below shows different programmable thermostat settings you should definitely know.

Thank you actionac.net for sharing this infographic. Please include attribution to actionac.net with this graphic if you would like to use it on your site.

Non-programmable Thermostats

Non-programmable thermostats, sometimes called manual thermostats, provide a more traditional way to control the heating and cooling system in your home or business. You’re probably familiar with these thermostats, which allow you to manually choose the temperature of the building at any given time. Some people prefer non-programmable thermostats because they make it easier to change the climate of your home in response to changing weather conditions -- with programmable thermostats, it can be harder to alter the program when a heat wave or a cold front comes in unexpectedly. In addition, manual thermostats usually cost less upfront.

If you are retired, work at home, or spend all day in the house caring for kids, you might always be around to change the thermostat, so a non-programmable thermostat may be just as good as programmable one. Also, if you live in a place where the outside temperature doesn’t vary much, leaving a non-programmable thermostat at a single temperature level can ensure that your building maintains a consistent temperature too.

To meet the specific needs of your home or business, National Air Warehouse carries both programmable and non-programmable thermostats. Contact us today to find out more about what we offer!

Copper refrigerant lines play an essential role in air conditioning systems: They are responsible for carrying the refrigerant between the condensing unit and the evaporator coil. There are two copper lines that run between the condenser and the evaporator coil. The larger line is known as the suction line, return line, or vapor line. It carries cool gas, so it must be insulated with tubing. The second copper line is small and bare, and it is commonly known as the liquid line. Because the liquid line carries warm liquid, no insulation is needed.

When to Change Out Copper Refrigerant Lines

As you might expect, copper refrigerant lines need to be changed out whenever you are replacing an air conditioning or installing a new one. However, it is also important to note that copper refrigerant lines are also recommended to be changed out when upgrading your air conditioning system. It can be tempting to reuse old copper refrigerant lines after a system upgrade, but it is never a good idea. In order for a copper line to work properly, it needs to be fully dehydrated. An old copper refrigerant line may not be adequately sealed from moisture. As a result, any moisture in the line will combine with the refrigerant to form an acid, which can damage the compressor motor.

You might also need to replace your copper refrigerant line in case of leaking. A sure sign of a refrigerant line leak is an oil stain, because oil travels through the air conditioning system alongside the refrigerant, and it remains visible even after the refrigerant has boiled off. Some of the most common causes of leaks include:

• Mechanical damage. When outdoor copper refrigerant lines get bumped by lawnmowers, exposed to harsh weather, or stepped on by kids or workers, it can cause a leak.

• Corrosion. If the copper refrigerant line is exposed to contaminants, it can lead to corrosion and subsequent leaks. This could occur through direct contact with ductwork or other dissimilar metals, or it could result from exposure to a corrosive atmosphere from chemical storage or furniture refinishing

• Settlement. When the building or the condenser settles, it puts stress on the copper refrigerant lines, making leaks more likely.

Ultimately, a leaky line can reduce the quality of the performance of your air conditioning system, so it is critical to resolve the problem as quickly as possible.

Changing Out Your Copper Refrigerant Lines

When changing out copper refrigerant lines, you need to make sure that the length and the diameter of the new line fit with your air conditioning system. National Air Warehouse offers a wide variety of copper refrigerant line options, and we can help you figure out which one is right for your project. Contact us today for help!

For home builders and remodelers, summer is a peak time for business. With good weather and lots of light, you can really make progress on major construction projects. At this time of year, most people aren’t worried about indoor heating, but for all of your home building projects, you need to think about the best way to make sure the house stays warm during the cold, dark days of winter. That means choosing the ideal furnace for the building.

One of the factors to consider when choosing between furnaces is indoor airflow -- that is, the way that warm air flows out of the furnace. You can choose between an upflow furnace (with top discharge), a downflow furnace (with bottom discharge), and a horizontal furnace (with side discharge). As a home builder or remodeler, there are important things you need to know about each time of system in order to find the best one for your project and install it in an appropriate location.

Upflow Furnace (Top Discharge)

An upflow furnace draws air in from the bottom of the unit. The air is warmed in the heat exchanger, and then it is discharged from the top of the furnace into the ductwork of the house. Because heat rises, it is best to place an upflow furnace in a basement or crawlspace. If the building you are working on has a basement with a low ceiling, you need to make sure that the furnace fits in the space. That often means choosing a “lowboy” furnace (which is typically about 4 feet in height), rather than a “highboy” furnace (which is usually about 6 feet in height).

Downflow Furnace (Bottom Discharge)

Just as you would assume, the air travels through a downflow furnace in the opposite direction as it does through an upflow furnace. The air enters at the top, is warmed in the exchanger, and then is released from the bottom of the furnace into the ductwork of the home. Often, a downflow furnace is placed in the attic, but it can also be installed in the garage or some other location on the main level. A downflow furnace can be a good choice for a home that does not have a basement or a crawl space.

Horizontal Furnace (Side Discharge)

A horizontal furnace takes air in from one side, warms it in the exchanger, and then pushes it out into the ductwork from the opposite side. Horizontal furnaces, like “lowboy” upflow furnaces, usually have a relatively low vertical clearance, so they can be installed in basements and crawlspaces. When choosing between different horizontal furnaces for a home with highly specific space constraints, you may want to check to see if the furnace discharges the air to the left or to the right, in order to ensure that it will work for your project.

National Air Warehouse offers a wide range of upflow furnaces, downflow furnaces, and horizontal furnaces. If you are building or remodeling a home this summer and need help finding the right one for your project, contact us today!

This summer, you’ll be relying on your home air conditioner to keep your house cool. Memorial Day is only a week away, which means that for the next few months, your air conditioner will probably be running most of the time. Before the dog days of summer hit, it is critical to make sure your air conditioner is working properly, but you also need to think about indoor air quality. Even a well-functioning air conditioner can’t prevent the circulation of environmental pollutants without an air filtration system.

In recent years, better home construction and insulation methods have made buildings air-tight and easier to cool, which has improved energy efficiency. At the same time, however, these improvements make it harder for pollutants to escape from your home and be replaced by fresh air. As a result, the Environmental Protection Agency (EPA) now ranks indoor air pollutants among the top five environmental health risks. Your family may be exposed to a wide range of damaging particles in the air, including contaminants that can trigger allergies and cause breathing problems. Dust, pollen, pet dander, smoke, and even mold spores are all commonly found in the air in people’s homes.

Home Air Filtration System Options

One way to improve the air quality in your home is to install a home air filtration system. When choosing between filters, one of the most important factors to consider is the minimum efficiency reporting value (MERV) rating, which ranks home air filtration systems on a scale of 1 to 20, based on the following three categories:

• The filter’s ability to remove particles from the air.
• The filter’s ability to resist air flow.
• The expected operating lifetime of the filtration system.

Some of the most common types of systems you’ll find on the market today include pleated media air filters and washable/reusable air filters. There are benefits and drawbacks to each type, so you must consider your individual situation when choosing between them.

The main benefit of pleated media air filters is that they are particularly efficient for catching both small and large particles in the air, compared to some of the other types of filters that are available. They also operate relatively quietly, and they have relatively low airflow resistance. The MERV rating for pleated media air filters typically ranges between 5 and 13.

The best thing about washable/reusable air filters is their durability. They are designed to last a long time, and the washable filters are easy to clean and reuse. It is important to note that the MERV rating can vary widely. For traditional models, the rating is usually between 2 and 8, but for high efficiency models, it can be as high as 14 or even 16, depending on the airflow.
National Air Warehouse offers both pleated media air filters and washable/reusable air filters. With hot temperatures right around the corner, now is the time to add one to your home air conditioning system in order to ensure that you stay cool and healthy all summer long! If you need more help determining which air filtration system is right for your home, contact us today!