1. What is HVAC? What does HVAC stand for?
The acronym HVAC stands for heating, ventilation and air conditioning. When someone refers to an HVAC system, they are talking about the equipment that is used to keep a home or building comfortable through the use of heated and cooled air. A basic HVAC system is comprised of a furnace, an air conditioner and a series of ducts. The air conditioner and furnace heat and cool air, and a blower forces it through the ducts. It then blows out of registers around the home or building. A single thermostat typically controls the entire system.
A standard HVAC system consists of an outdoor unit, which is the largest component, and an indoor unit, which is smaller. Many air conditioners, furnaces and heat pumps are designed to work together, so it's often better to replace the entire system than it is to replace a single component. It's also important not to overlook the importance of the ducts, which can cause problems when they're not adequately sealed or when they're extremely dirty.
2. Is there still a warranty on my furnace, air conditioner or other HVAC equipment?
When you buy new heating and cooling equipment, a warranty is included. A portion of what you pay goes toward that warranty, so you might as well get as much out of it as possible. Even if you know when your air conditioner, furnace or other equipment was purchased, you may be uncertain about how long the warranty period should be in effect. If you're not sure when it was installed, you'll have nothing to go on at all.
One way to find out whether or not heating and cooling equipment is under warranty is by tracking down the model and serial numbers and contacting the manufacturer. An easier option is to have HVAC contractors do this for you. Many of them can decipher serial numbers to get a rough idea about whether or not a unit is likely to be under warranty. If any warranty is left on any of the components, you can save a lot of money on repairs.
3. What's included in a precision tune-up, and how much does it typically cost?
A precision tune-up is one that includes the inspection, cleaning and servicing of your HVAC equipment. The precise steps that are included vary depending on the contractor who's doing the work and on the kind of equipment that's involved. If issues are found during the inspection phase, the servicing phase will be more involved. It's well worth it to have this work done because it can keep your equipment operating efficiently, which helps to keep energy costs in check.
As far as pricing goes, that also varies. However, it's a lot cheaper to pay for an annual precision tune-up than it is to pay for unexpected repairs. When HVAC systems aren't maintained properly, they're more likely to fail completely and may not last as long as they should. The cost of a precision tune-up is a small price to pay for longer equipment lifespans and more reliable heating and cooling.
4. How do HVAC systems work?
HVAC systems are heating, ventilation and air conditioning systems. They are found in residential and commercial buildings. They typically consist of at least one indoor unit and one outdoor unit, but there may be several units depending on the size of the building or home.
HVAC systems work by adding heat to or removing heat from the air. People often assume that air conditioners actually chill the air, but that's not the case. They actually remove heat and moisture, which results in cooler air. Furnaces do actually heat air and blow it through ducts in a home. Heat pumps, however, pull warm air from outside the home and bring it inside, so they don't actually increase the temperature of the air.
5. How do you control an HVAC system?
Most HVAC systems are controlled by a single thermostat. The thermostat, or temperature control, is typically mounted on a wall in a convenient, easy-to-reach place. Analog and digital thermostats are available, and furnaces, heat pumps and air conditioners are all affected by adjustments that are made to the temp control. Whether it's with a knob or with a keypad, you set the desired temperature. If the air in the home falls to a temperature below that point, the furnace kicks in to bring it back up to the desired range. If the air in the home rises above the desired temperature, the air conditioner kicks on to remove warm air and moisture and then blow the cooler air out, which results in a cooler temperature. Heat pumps can both heat and cool a home, but they only work well in places that experience mild winters.
6. The ducts in my home make popping noises whenever the furnace turns on or off. Why?
This is a very aggravating problem, and it's almost always caused by improperly sized ducts. More specifically, these noises occur when the ducts in a home are too small for its HVAC system. When the furnace kicks on, the volume of air that is forced through the ducts is too high, so they expand. When they do, they often make noise. While the air is flowing through, things are usually quiet. When the air stops, however, the ducts contract. Because they're made of sheet metal, they make that loud, annoying popping noise.
7. What's all this talk about switching refrigerants?
If you've done any research about air conditioners in the last few years, you've probably heard at least a few things about the gradual phasing out of certain refrigerants. For decades, refrigerants like R-22 were used in HVAC and refrigeration. However, it has since been discovered that these refrigerants are very detrimental to the environment. In an effort to reduce the negative impact of heating and cooling on the atmosphere, newer, more eco-friendly refrigerants have been developed. R-410A is a prime example.
While R-22 and other refrigerants will remain available for a while, they will gradually be phased out. Therefore, it's smart to switch to an R-410A system preemptively. Eventually, there won't be any other options.
8. The outdoor unit of my HVAC system needs to be replaced. Should I replace the indoor one as well?
Most HVAC contractors recommend replacing them both at the same time. This is a smart thing to do for a few reasons. For one thing, indoor and outdoor units are designed to work together. When they're purchased and installed as a set, they will be more efficient and should work a lot more effectively.
Another reason to replace indoor and outdoor units at the same time is because they will both have warranty periods that begin at the same time. Furthermore, odds are that your existing units are roughly the same age. If you only replace one of them now, you can be sure that you'll be replacing the other one before too long. You can usually get a significant discount on equipment and labor by purchasing them both at the same time.
9. Is routine maintenance really that important for residential HVAC systems?
For some reason, many homeowners are under the impression that routine maintenance isn't a big deal for home HVAC systems. Nothing could be further from the truth. Without being periodically cleaned, inspected and serviced, air conditioners, furnaces and other heating and cooling equipment start operating less efficiently and begin requiring more and more repairs. Unscheduled repairs cost a lot more than tune-ups, and they usually mean that you have to go without your heating and cooling equipment for a while. The best heating and cooling companies offer extensive tune-up services for very reasonable prices, and it's worth it to invest in them.
10. My heating and cooling system keeps freezing up. Why?
This isn't a question that can be answered without taking a look at your system. The entire system isn't likely to freeze up. Instead, it's probably either your air conditioner or your furnace. If you have a heat pump, of course, it could be freezing up as well. As far as why it's doing so, that's a question that's best left to an experienced heating and cooling professional.
There are a few basic HVAC troubleshooting steps that you can attempt. The first and most obvious one is to confirm that power is going to the system. A tripped breaker or blown fuse could be to blame, and you can avoid paying for a service call by ruling it out first. If that's not the problem, try to figure out whether or not the system is responding at all. Any information you can provide on the phone will make the service call that much more productive.
11. I've heard about HVAC zoning systems, but what are they?
Heating and cooling zoning refers to having the ability to heat or cool specific parts, or zones, of a home or building. This is accomplished through the use of ducts that have flaps that open and shut. It is most commonly available on ductless systems. Multiple indoor blower units are installed in the home and are controlled by a central temp control. There is usually just one outdoor unit, but there may be several if a home or building is quite large.
Zoned systems are convenient because they allow you to adjust temperatures in specific parts of the home. In this way, you can keep energy costs as low as possible and enjoy superior comfort.
12. What are the most common types of HVAC systems?
When someone refers to an HVAC system, he is almost certainly talking about one that includes a furnace, central air conditioner and ductwork. That is the standard type of system that is used, but many additional options have been rising in popularity in recent years.
In milder parts of the country, heat pump systems are skyrocketing in popularity. Instead of having separate units for heating and cooling a home, you just have a single heat pump unit. This results in more efficient operation, which produces more affordable energy bills.
Ductless systems are also more popular than ever. They consist of at least one outdoor unit and at least one indoor blower unit. They were originally used primarily for homes and buildings without existing ductwork, but they're increasingly being used for their zoned heating and cooling capabilities and other perks.
13. Is humidifier installation complicated? Are these components easy to maintain?
A talented heating and cooling contractor should be able to install a humidifier on your system in no time. That's especially true if you have a standard heating and cooling system with ducts. Experienced technicians can generally install humidifiers in a few simple steps. However, this isn't a do-it-yourself project. The only way to ensure that the humidifier will work properly is by having it installed by a professional.
As far as maintenance goes, it's simple. The most important thing is making sure that the drain hose is clear and working properly. Otherwise, you'll have a big mess on your hands. It's easy to check this yourself. However, you should have HVAC contractors perform basic maintenance on your humidifier when they come out to service your air conditioner, furnace or heat pump. By doing so, you should be able to ward off costly HVAC repairs more easily.
14. How does an air conditioner cool your home?
Modern air conditioning systems work by pumping, expanding and contracting refrigerant to pull heat and moisture from the air. Refrigerant starts as a liquid, and the compressor squeezes or compresses it until it turns into a gas. When this happens, it gets really hot because it absorbs heat. This heat is then blown outdoors, so it is removed from the air inside the home. The cooled air is blown over coils before being sent through the ducts. From there, it is pumped out through registers around the home.
15. I need a new air conditioner. Which one is the correct size?
There's no quick and easy way to determine what size an air conditioning system needs to be to adequately cool a home. You may be tempted to buy the most powerful unit available, but this can actually backfire. If the capacity is needlessly high, it can result in inefficient operation. The system may be unable to remove moisture from the air, so you will be left with moist, unpleasant air. Furthermore, it will use a lot more energy, so your bills will be unusually high.
Experienced HVAC contractors perform load calculations to determine the capacity that's needed to cool a home. The process is complex, and it is based on a number of industry standards. The contractor should be able to explain how he arrived at the recommended capacity, so be sure to ask.
16. I've seen ratings for heat pumps and air conditioners. What are they all about?
There are separate efficiency ratings for air conditioners and heat pumps. Air conditioners are given SEER ratings, or Seasonal Energy Efficiency Ratio ratings. They reflect the amount of energy that is needed to cool a home. The higher the rating, the more efficient the equipment. A minimum rating of 13 is required by the United States government.
Heat pumps are given HSPF ratings, or Heating Seasonal Performance Factor ratings. This rating equals the heating output of a typical season in BTUs divided by the amount of energy that's required in watt hours. A higher rating equals more efficient operation. Heat pumps are generally much more efficient than other types of heating and cooling equipment.
17. What is a heat pump?
One way to think of a heat pump is as equipment that can heat and cool a home. It does this by adding or removing warm air to the air inside a home. When a home needs to be cooler, a heat pump takes warm air from inside a home and sends it outside. When a home needs to be warmer, a heat pump pulls warm air from outside the home and brings it inside. Heat pumps are highly efficient, but it's important to find an HVAC repair company that is experienced in servicing this type of equipment to ensure high-quality operation over the long term.
18. What kind of rating is used for modern furnaces?
The rating that is used to denote the efficiency of a furnace is called an AFUE rating, or Annual Fuel Utilization Efficiency rating. The rating is a percentage that reflects the amount of heat that's produced versus the amount of fuel that is required. Higher percentages equal greater efficiency. By law, all furnaces must have AFUE ratings of 78 percent or higher.
19. My contractor has recommended a variable-speed furnace. Why?
Variable-speed furnaces use variable-speed compressors. Regular compressors only have two modes: on and off. They must kick on to make furnaces work and turn off to make them stop. This requires a lot of energy. Variable-speed furnaces, on the other hand, have compressors that operate at variable speeds. This makes it easier for them to maintain consistent temperatures, and a lot less energy is required. Not surprisingly, variable-speed furnaces have skyrocketed in popularity as concerns about energy costs have grown.
In addition to using less energy, variable-speed furnaces result in superior indoor comfort. You are much less likely to deal with indoor temperatures that are either too hot or too cold, so you shouldn't have to adjust the thermostat constantly.