Portable Air Conditioner vs Window Air Conditioner

Portable Air Conditioner vs Window Air Conditioner which is the best choice, it depends on the usage and the needs. If you want to have a movable air conditioner so you can pace whenever you are, I suggest the portable AC. But portable units tend to be noisier than permanently mounted ones. It may also become a tiresome chore if you opt for a portable unit where the condensation has to be removed manually. While window type AC is designed to fit in a window of a room and hence do not take up a lot of space and can fit in just about any room. They function as any other air conditioner does, they are very affordable, do not make a lot of noise and are also long-lasting.

Portable Air Conditioner vs Window Air Conditioner

If you have a choice, a window unit will always be more efficient and give you a bigger bang for your buck. After the refrigerant is compressed to a liquid, the heat from that compression must be expelled to the outside by blowing air over the condenser fins. With a window unit (or a central or split system), the condenser fins and coils are already outside and are easily cooled with the exterior fan.

A “portable” or free-standing unit has the condenser fins inside the unit inside your home. This is why these units have a flexible duct connecting to a panel to be installed in the window. The better units have two ducts, so that outside air is drawn into the unit via the first duct to cool the condenser and pumped back outside through the second duct.

But I haven’t seen one of these in a long time. Most units seem to have just one duct. This means that air from the room is being used to cool the condenser and being blown outside. You are literally using some of the room air you just cooled to reduce the temperature of the refrigerant and throwing it away. It’s terribly inefficient compared to a window unit or central system.

Also, since you are pumping some air out of the room, you are creating a negative pressure. To balance the pressure, that air must be replaced, otherwise you would create a vacuum inside. So some warm air from the outside is further encouraged to seep inside through poor window seals and so forth.

Another disadvantage of a portable unit is that water from the room air that condenses on the evaporator coils must be collected and regularly disposed, otherwise your floor would get soaked. A window unit doesn’t have this problem because the condensate can be drained outside.

The only real benefit of a portable unit in my opinion is aesthetics. Some people just don’t like those ugly metal boxes sticking out of their windows, or their landlord or HOA doesn’t allow it.

Window air conditioners win this battle fair and square. The problem with portable units is the compressor and fan motors are inside which means it will tend to be on the noisy side. Another problem is they take air from the room to cool itself off and puts that air outside.

This means that somewhere, hot outside air is coming into your living area. A dual hoze model doesn’t have this problem but still has the moving parts are all inside. With a window unit the compressor and fan motor are outside so they tend to run quieter.

Now the cheap models will still be rather noisy where as more expensive models will be quieter. Window units also suck air from outside to cool them selves off so there’s no hot air leaking into your living area.

Window Air Conditioner vs Mini Splits Air Conditioner

Mini-split AC units may be ideal for homes that cannot accommodate a central AC system or if you have an affordability issue. In these cases, a ductless cooling system may be the best option for you. Mini-Splits are quickly gaining popularity in the US market, and with good reason. They are versatile and many newer models have sleek units with low noise and high cooling/heating power. I would go for a Lennox mini split air conditioner because they seem to be the best built and still use a insulated metal divider wall between the inside ans outside.


Sizing Residential Heating and Air Conditioning Systems

The size of the heating system is directly related to the amount of heat lost from the house or building. All structures lose heat to the outdoors or to adjacent unheated or partially heated spaces when the temperatures of the outdoor air or adjacent spaces are colder than those inside the structure. The heat within the building is normally lost by transmission through the building materials and by infiltration around doors and windows.

The loss of heat from a structure must be replaced at the same rate that it is lost. Consequently, determining the correct size of the heat system and the rated capacity of the heating plant required by the steam are very important. Unfortunately, many heating and/or cooling systems are either undersized or oversized, with the latter being the most common mistake.

Undersizing means that the heating and/or cooling equipment does not have the capacity (output) to meet the heating and cooling requirements of the structure. Oversizing means that the heating and/or cooling equipment has more capacity than required. Both undersizing and oversizing are caused by using guestimates or rule-of-thumb sizing calculation methods.

The Results of Oversizing and Undersizing

Oversized heating equipment is more expensive to install, operates inefficiently, uses more energy resulting in higher fuel bills, creates uncomfortable indoor temperatures by providing more heat than the structure requires, and produces wide temperature swings.

Oversized heating equipment also breaks down more often. Oversized units require larger air flow, resulting in noisier operation.
Undersized heating equipment lacks the capacity to provide sufficient heat, especially during extreme cold spells.

Oversized air conditioners and heat pumps create higher than normal humidity levels indoors because they do not run often enough to dehumidfy the air. This is known as short-cycling. The dampness in the air can also result in unhealthy mold growth indoors.

This article describes several methods for calculating heat loss, ranging from rule-of-thumb methods to the more precise method of using overall coefficients of heat transmission (U-values) computed for the various construction materials and combinations of construction materials through which heat is commonly transmitted.

Rule-of-Thumb Methods

There is nothing wrong with using a rule-of-thumb method when making an initial rough estimate of the heating/cooling load requirements for a structure. But it should be used as nothing more than a benchmark from which the true and precise calculations are made.

It provides the equipment installer/contractor and the homeowner with some idea of how much the heating and/or cooling system will cost. But correct sizing will involve the consideration of many different factors, including but not limited to the following:

  1. Size, shape, and orientation of the structure
  2. Local climate
  3. Type, location, and number of windows
  4. Type and amount of insulation
  5. Number and ages of occupants
  6. Structure design
  7. Construction materials
  8. Planned use of the heating/cooling system
  9. Condition of the distribution system (ducts or pipes)
  10. Air infiltration rates

There are three common rule-of-thumb methods used by contractors/ installers to size heating/cooling equipment.

Upgrade Method.

A common rule-of-thumb method is to install a furnace or boiler the same size or larger than the original one in an existing house or building. The problem with this approach is that the original equipment may have been incorrectly sized.

Furthermore, many changes have probably been made to an existing structure over the years, and these changes will have changed the load requirements for new equipment. The house has most likely had its insulation levels increased, because adding insulation in the attic, caulking around windows and doors, or installing double-glazed windows are relatively inexpensive upgrades.

If the HVAC contractor looks at the metal furnace or boiler tag (nameplate) specifying its output, Btus per hour, and so forth, and advises you to purchase and install one of the same or higher output, get another estimate. Unfortunately, this is an all too common method used by many to size equipment. Correct sizing involves the consideration of many different factors.

Sizing by Square Footage Method.

Another rule-of-thumb method is to size by the square foot area of the house or building. This is called the “sizing by square footage” method. It is one of the most commonly used of the inaccurate sizing methods.

It involves taking the square footage area of the structure and multiplying by a specific value. For example, a typical value assigned to air conditioning equipment is 1 ton (12,000 Btu/h) per 500 square feet of space (46 m2).

It fails to take into consideration any of the variables listed above.

Chart Method.

The so-called chart method of sizing heating/ cooling equipment involves filling in the blanks on a prepared chart. The chart lists the following:

  • Floor area of each of the heated rooms and spaces
  • Insulation levels in the floors, walls, and ceilings
  • House category (closest description of the type of house)

When all the required information is entered on the prepared form, multiply both the upper and lower values for heat loss in Btu per hour per square foot (from the data table used in conjunction with the chart) by the floor area of the house to estimate the required heating range. This estimating method does not take into consideration house location, design, or many of the other factors listed above.

Most Important Skills You’ll Learn in HVAC Training

With a focus on energy efficiency and environmental friendliness, industrial, commercial, and residential building projects require HVAC Technicians to have more finely-honed skills than ever. Have you ever considered working in the heating, ventilation, air conditioning and refrigeration industry? You’ll need to be trained in the latest technologies and systems.

You won’t be able to install, maintain, and repair equipment in homes and businesses until you learn some basic theory, best practices, hardcore skills, and industry trends.

Most Important Skills You'll Learn in HVAC Training

HVAC training teaches you how to install and troubleshoot commercial and residential HVAC systems. In a great HVAC training program, you’ll learn what you need to know:

Electricity Principles and Theory

Because of all the work with wires, circuits, and conductors, it’s important to understand how electricity works. It’s not just about proper installation and maintenance; it’s also about safety. You’ll learn about current flows, magnetism, and how to apply formulas like Ohm’s Law (which states that current strength is directly proportional to voltage).

Refrigeration Concepts and Practices

To really understand how heating and AC systems operate, you’ll need a grasp of refrigeration concepts and best practices. Like with electricity, this is a safety issue as much as it is a practical one; safety for your own personal protection, like understanding how to correctly use hand and power tools, as well as for environmental protection. You’ll learn about EPA laws, heating and cooling pumps, and the math skills you need to  understand how system components work.

HVAC Controls and Components

With some basic concepts and principles under your belt, you’ll also want to know how to chart controls and components in both residential and commercial HVAC systems. Lessons in ladder diagram development will help here. These diagrams, or schematics, show components like power supply, what path the power takes, the load and the switch components. The diagrams will give you an in-and-out knowledge of how controls and components work in an easy-to-understand way.

Energy Conservation and HVAC Equipment

To get a jump start on the latest developments in HVAC installation and maintenance, you’ll need to learn about energy conservation practices and equipment. It’s important for heating and cooling systems to be green, energy efficient. Heat and cold recovery are big, the idea being they energy demands and costs can be reduced by pre-heating or pre-cooling fresh air before it enters a room. This puts less stress on the entire system and less of a financial burden on the building owner or tenant.

The demand for professional, knowledgeable, well-trained HVAC technicians is there; jobs are expected to grow 13 percent over the next ten years. But you need to be ready. If you want to acquire the knowledge, skills, and abilities mentioned above, take a look at HVAC Training programs. To get started on a bright future in the HVAC world, apply to HVAC Training programs today.

What Will You Learn in HVAC School?

Are you thinking about becoming an HVAC technician? To be successful in an industry like this, you need to be skilled in working on increasingly high-tech heating, ventilation, air conditioning and refrigeration equipment. To do that, you need to learn a lot of complex concepts.

You can learn all about these concepts, such as the refrigeration cycle and the laws of thermodynamics, in HVAC school.

What Will You Learn in HVAC School?

HVAC training teaches you how to install and troubleshoot commercial and residential HVAC systems. Students typically also receive instruction in proper refrigerant handling to help prepare them for EPA Section 608 Technician Certification.

HVAC School – Is It Worth It?

Let’s get the big question out of the way. Is HVAC school worth the cost of tuition, fees and books? Our opinion: YES! Here’s why:

  1. Employers prefer applicants with technical training.
  2. HVAC school is shorter than community college and apprenticeships: 6 months versus 2 to 5 years.
  3. Hands-on training—no Gen Eds like english.
  4. Part-time and flexible training schedule options are available for people who have other responsibilities, like day jobs.
  5. People with formal HVAC training have higher earning potential.
  6. Greater career opportunities are available to technicians who have attended HVAC school.

HVAC Education: What You Will Learn in School

Unlike many skilled trades, apprenticeship is not the most common path to an HVAC career. Working on HVAC equipment requires a combination of skills:

  1. Electrical
  2. Pipefitting
  3. Soldering

The right HVAC program equips people with well-rounded training and hands-on practice with the latest tools and technologies that professionals are currently employing in the field.

The Different HVAC Courses

Here’s a closer look at the courses offered in an HVAC program.

Fundamentals of Refrigeration

Refrigerants are used in many types of HVAC units.2 They help with the transfer of heat. A class in the Fundamentals of Refrigeration includes instruction in the following subjects:

  • The laws of thermodynamics
  • The refrigeration cycle
  • Pressure and temperature relationships
  • Refrigerant management safety practices
  • How to install, test and support a refrigeration system

Fundamentals of Electricity

HVAC students also learn about electrical concepts and theories used in the HVAC industry. Lessons in a Fundamentals of Electricity course consist of a range of subjects:

  • Electrical distribution systems, voltage circuits and low voltage controls.
  • Wiring diagrams
  • Installation and repair of electrical wiring and controls for residential and commercial HVAC units

Advanced Troubleshooting

When HVAC systems aren’t working, techs often rely on basic and advanced troubleshooting techniques to diagnose and fix the problem. These methods can be learned in an advanced troubleshooting class:

  • Troubleshooting electric heat, gas furnaces, oil heating systems and heat pump systems
  • Plotting the refrigeration cycle

Comfort Systems

Comfort systems courses teach you how to work with residential and commercial HVAC equipment. Instructions and training on the following are covered in courses like these:

  • Cooling towers and chilled water systems
  • Psychometrics, split systems, comfort system accessories and valves
  • Training in safety practices to use during the installation, maintenance and repair of residential and commercial HVAC equipment

Refrigeration Systems and Practices

This course is an introduction to refrigeration systems and their parts. It includes training in how to install, test and service refrigeration systems. It also introduces students to piping, soldering, welding and brazing.

Additional Training Options

Electro-Mechanical Technologies – Electro-mechanical technologies is a field of its own, but many of the courses overlap with HVAC training courses:

  • Residential and commercial electrical wiring is covered.
  • Students learn how to apply basic electrical principles to the installation, repair and maintenance of HVAC/R voltage circuits, wiring panels and feeder circuits.
  • A solar module offers an overview of how solar panels works and the science of photovoltaic energy.

HVAC Career

Job growth in HVAC service and repair is set to be much faster than average in the coming years than other industries. HVAC training can give techs a competitive advantage over job applicants fresh out of high school and sets them up for a career that can last throughout life.


Heating, air conditioning, indoor air quality and other HVAC topics are ones that are commonly misunderstood due to several persistent myths. You don’t know what you don’t know. This tautological statement may seem like nonsense, but it certainly applies to several areas in our lives.

HVAC is a deeper rabbit hole of complex equipment and processes than many people realize. As a result, a lot of misconceptions crop up around it.

While this isn’t normally an issue, it can be at the cost of your comfort, wallet, or even safety if you don’t know the in’s and out’s of HVAC in a way that allows you to make good decisions.

So let’s start making some better decisions, starting with those based on common HVAC myths.

We’ve already detailed some common myths surrounding heating and cooling, respectively, and this article takes a look at some misconceptions that cross the lines of heating and cooling to cover ALL HVAC processes.


MYTH: Keep your thermostat set to the same temperature throughout the day and night because it takes more energy to heat up a cold room than to simply maintain its temperature.

FACT: If this misconception was true, then there would be no need for programmable thermostats which adjust the temperature in your home throughout the day. It actually takes a lot less energy to warm up a cold house in the morning than to maintain a consistent temperature throughout the day and night.

Here are some truthful tips:

  • Buy a programmable thermostat and learn how to use it.
  • Setting the temperature back just a couple degrees throughout the day, when you are away from home or asleep, can significantly reduce your heating and cooling costs.
  • Dress appropriately for the season, which means wearing more clothing in the winter and less in the summer.
  • Close your blinds and drapes during the night and when it is cold out. Drapes and curtains help insulate your home.
  • Open up blinds and drapes during the day to let the natural heating rays of the sun into your home. Keep your registers and vents free and clear of any obstructions.
  • We recommend keeping your thermostat set at around 68 degrees Fahrenheit during the winter and 78 degrees when in need of air conditioning. Set the temperature forward or back around 8 degrees while home or asleep for significant heating and cooling savings.

MYTH: Duct tape is a good product for sealing air duct leaks.

FACT: Ironically, duct tape is not a good product to seal air ducts. It tends to peel and not stick very well.

If you are sealing your air ducts, we highly recommend going with a professional to seal your air ducts. If you are sealing your air ducts yourself, we suggest using aluminum foil tape or, preferably, mastic sealant.

The mastic sealant is actually the best way to seal your air ducts. Look for any exposed duct connections and clean them off first before applying any aluminum foil tape or mastic sealant.

MYTH: Switching to portable electric heaters will save you money and energy

FACT: This all depends on the circumstances. If you are in one spot and have a space heater nearby, then turn off your central heating and you will be saving some money and energy.

Unfortunately, when most people use portable heaters, they also have the central heating system running as well. If that’s the case, you are only increasing your home’s energy consumption.

In general, gas heating is a lot more efficient than electrical heating. If you are trying to save money and energy by using portable space heaters, then make sure you turn off your central heating system while you do it. And don’t forget to turn off the space heater when you leave the immediate area.

MYTH: Windows are the greatest source of heating and cooling loss in my home.

FACT: While this may be true, it’s much more likely that you’re losing more energy out of your ceiling/roof. In the typical home, around half of all heating and cooling loss comes from air leaks and poor insulation in walls and the ceiling/roof.

Still, all air leaks around your windows should be fixed. Proper caulking and upkeep will significantly reduce your heating and cooling bills.

MYTH: The bigger the air conditioner, the better it will be able to cool my house.

FACT: Wrong! A larger HVAC system does not necessarily mean better savings or comfort. When replacing your heating or cooling system, it’s important to make sure it is properly sized. An oversized unit may satisfactorily heat and cool your home, but it will likely have frequent cyclings on and off, which can create high humidity conditions inside the home. Other comfort problems, such as dust from leaking ductwork and poor air distribution are also likely to occur.

Alternatively, an undersized unit may run for longer than necessary driving up your energy bill. If your HVAC technician is doing his or her job correctly, they will measure your home and fully analyze your current system, including ductwork, insulation levels, and other factors that contribute to choosing the properly sized system for your home. Anyone who simply replaces your existing system with a similarly sized one is taking a very risky shortcut which could lead to high energy bills, voided warranties, and other major problems.

According to ENERGY STAR, over half of all new HVAC systems are improperly installed, which “can reduce performance by as much as 30%” (energystar.gov). To help reduce the risk of an improperly installed HVAC system, always ask your prospective HVAC contractor if they will be measuring your home and how they will calculate the correct size for your new equipment. You also want to be assured that the system will work with your existing ductwork.

A properly sized system may run longer than an oversized system, but it will be more energy efficient and help alleviate uncomfortable moisture conditions.

MYTH: All it takes to properly size a new HVAC system is the square footage of the home.

FACT: There are a lot of factors that go into selecting and installing a new heating and/or cooling system. Not only must square footage be taken into account, but your technician should also inspect windows, window orientation, air leakage, volume, existing ductwork, and insulation and ventilation levels. If you simply used the square footage of the home, you would probably end up with an oversized system and higher upfront costs and energy bills.

When any HVAC contractor is bidding for your business, ask them how they will size your new system. Ask for a Manual J or equivalent report before agreeing to the installation.

MYTH: Fans and ceiling fans help cool spaces even while you are away.

FACT: Ceiling fans don’t actually heat or cool a room. Fans make people and animals feel cooler, but only because of the wind-chill effect. It doesn’t actually lower the temperature of the room. Still, we all know how good a nice breeze feels on a warm summer day. Ceiling fans allow your to set the thermostat higher while still feeling a similar comfort level.

Ceiling fans can also help your feel warmer in the winter. All you have to do is switch the little black switch at the base of the ceiling fan to reverse the fans direction, creating an updraft that helps move warm air near the ceiling down to the living spaces below.

The lesson? Only use ceiling fans to supplement your heating and cooling when you are in the room. Turn off fans when you leave. Oh, and turn your HVAC system or set it back if you want to experience any kind of energy savings. While HVAC systems cost dollars per day, ceiling fans costs cents per day.

MYTH: Ceiling fans can only be used for cooling purposes.

FACT: Ceiling fans can help reduce your need for both air conditioning and heating. When the temperatures begin to drop, remember to flip the black switch at the base of your ceiling fan to reverse its direction.

When your fan runs in the opposite direction, the breeze is directed upwards, helping to force the warmer air near the ceiling down to the walls and into your living spaces. Since heat rises, this helps balance the temperature of your indoor spaces. Remember, ceiling fans cool people, not rooms. Turn off all fans before leaving the room.

MYTH: It’s easy to find out where air leaks around my home are.

FACT: While it may be easy to find air leaks around your doors and windows, there are many other parts of the home that could have severe insulation problems, such as areas around floors and ceilings, around chimneys, pipes, ductwork, and other hard-to-reach spots.

The best way to find all of the energy inefficiencies around the home is by scheduling a home energy audit with a professional. By using a blower door test and other procedures, they’ll be able to pinpoint the areas in your home where you should direct your energy efficiency improvements. After diagnosing your home and finding the biggest energy losses, you may discover that you had no idea where your biggest energy leaks were.

MYTH: The best way to solve a hot and clammy room is by sticking an air conditioner in the window.

FACT: While buying a window air conditioner may be the easiest was to cool down a room, you may have a more serious airflow problem with you central HVAC system. Ignoring the problem by simply sticking an A/C in the window will often aggravate the problem further. The best way to solve any hot or cold spots in the home is by scheduling professional HVAC maintenance twice a year and addressing the source of the problem without draining even more energy with a new window A/C.

A great way to improve the comfort inside your home year round is by investing some time and energy into weatherization improvements, such as attic insulation, duct sealing, and caulking around windows and doors.

MYTH: Increasing energy efficiency doesn’t increase the value of my home.

FACT: Energy efficiency improvements are one of the most sought-after home features. And the demand for energy-efficient features is growing. Lowering your energy bills not only benefits you while you live in the home, it’s likely to be a major selling point if you ever decide to sell.

According to the National Association of Realtors 2013 Profile of Home Buyers and Sellers, “heating and cooling costs were at least somewhat important to 85 percent of buyers.”

Additionally, the National Association of Home Builders (NAHB) came out with a 2015 study that ranked top influencers in home purchase decision, with “energy efficient” ranking in the #2 spot, second only to “safe community.”

Based on NAHB’s 2015 study of home buyers nationwide, consumers want sustainable, energy-efficient buildings:

  • 90% Safe community
  • 88% Energy efficient
  • 85% Low maintenance
  • 85% Lower operating costs
  • 84% Durable/Resilient

Closing off vents and registers will help reduce my heating and cooling costs.

FACT: Despite the fact that vents and registers have levers that allow you to close off airflow, it’s not a good idea. This is because central HVAC systems have been specifically designed for your home, balancing the pressure load throughout the home and duct system.

If you block one or more vents, either intentionally or not, you are affecting the way your HVAC system breathes in and out. If you upset the balance of your system, your system may develop airflow and pressure problems.

Your HVAC system outputs the same amount of conditioned air no matter how many vents or registers are closed. In addition to airflow problems, you may develop duct leaks as well. Go around your home and make sure that no furniture, rugs, drapes, clothing, or anything else is blocking your vents and registers.

HVAC Myths