Frequently Asked QuestionsYou Ask, We Answer
What kind of licensing should my HVAC contractor have?
In the State of Virginia: An HVAC business is required by law to have a business license for the county in which they are located. They are required to have a contractor’s license issued by the Department of Professional and Occupational Regulation. This contractor’s license should be the grade of license required for the monetary value of the contract being performed.
What kind of individual licensing is required for HVAC technicians?
If an HVAC technician is working under the supervision of a licensed journeyman or master, no license is required. However, if a technician is working without supervision, that technician must have a journeyman or master license issued by the Virginia Department of Professional and Occupational Regulation. If someone is working with a refrigerant, the Environmental Protection Agency requires that an apprentice obtain a refrigerant license within their first two years of apprenticeship. If a technician is working alone, they must have an EPA refrigerant license for the refrigeration system type that they are working on. Always ask to see a technicians EPA refrigerant license, and their state issued journeyman (or master) license.
I'm building an addition, can I just use the existing equipment to heat and cool the new space?
When a residence is being built, a heat load (Manual J) calculation is performed to determine the heating and cooling system capacity needed for the residence. It is a very specific calculation that takes into account hundreds of different factors. If a system is oversized or undersized it can cause serious problems for the residence. Therefore, when building an addition, it is important that a new heat load calculation is performed to determine the correct size needed for the new space. After the heat load calculation is performed there are a couple of options that can be done. You can replace the existing equipment with the correct size, or a new smaller system can be added to supplement the existing system for the addition. Do not let a contractor (who is not licensed to perform HVAC services) advise you to use the existing system. Heat load calculations are required by law.
Hours & Info
M-F 7:00 am to 5:00 pm.
For after hours emergency service please call us.
How long can I expect my equipment to last?
Typical life expectancy with proper maintenance:
- Gas Furnace or Air Handler – 15-20 years
- Air Conditioner – 15-18 years
- Heat Pump – 12-15 years
Why do I need a service contract?
Many problems can go undetected for some period of time, allowing other problems to be created. A maintenance contract will ensure a homeowner less problems, higher efficiency performance, and greater reliability from their system.
How often do I need to have my coils cleaned?
Cleaning evaporator and condensing coils is something that is done only as necessary. If a good filter is used inside our home, the indoor coil should not become dirty. The outdoor coil does not need to be cleaned unless there is noticeable dirt on them, in which case they should be cleaned promptly.
Do I need to cut back the bushes around my outdoor unit?
Most equipment manufacturers will recommend a minimum of 12 inches clearance around the outdoor unit, and ideally 18 inches clearance. For top discharge units, there should be 6-8 feet minimum clearance over the top of the unit.
Does it matter if my outdoor unit isn't level?
Unless a unit is severely tilted, it is more of a cosmetic concern. Some manufacturer will actually request that the outdoor unit be graded slightly away from the home.
Does a programmable thermostat really save me money?
Heat always flows from a higher temperature to a lower temperature. Heat will flow faster, with a greater temperature differential. By offsetting the temperature in our home throughout the day (usually when we are gone from the home) we cause our HVAC system to operate far less than it would have if we had not offset the temperature. So even though our system will operate for long periods of time when we return home, it was not running when we were gone. Creating a system with far less run time, and thereby reducing the utility bills.
Do I need a programmable or non-programmable thermostat?
Programmable thermostats are designed for homes where everyone leaves the home for the day. If someone is home all day, then the home would be uncomfortable if the temperature was offset. Usually, if someone is home throughout the day a non-programmable thermostat is a fine option.
I have a heat pump thermostat, what is the difference between Heat and E-Heat?
The “Heat” selection uses the heat pump first, and only brings on the electric heat if the heat pump is not maintaining the temperature set point selected. So if the temperature is set to 68 degrees, and the home has dropped to 66 degrees, in most cases the electric will come on. But the electric heat will only come on as needed to supplement the heat pump. This operation is far more efficient than pure electric heat. The “E-Heat” selection will use only the electric heat, and the heat pump will not come on. A homeowner may use this if their heat pump has failed.
What is the fan “Auto” and fan “On” feature?
Fan “Auto” is automatic operation. The fan will automatically turn on and off with a need for heating and cooling. If the fan is set to “On”, the fan will run all the time, regardless of whether the system is heating or cooling the home. This can be a good selection for many reasons. Air is cleaned only when the fan runs, so more fan run time means cleaner air. It is easier for an electric motor to run continuously, rather than start and stop. And running your fan all the time will help to even out hot and cold spots inside your home.
What should I set the temperature in my house for?
Home temperature is a personal choice. People are comfortable at very different temperatures. Select your temperature based on your own comfort level. Setting the thermostat lower in the winter, and higher in the summer will help to lower utility bills.
Indoor Units (Furnaces and Air Handlers) FAQs
My furnace is really old, is it safe to use?
By today’s standards, probably not. Older furnaces do not have many of the safety controls that more modern furnaces use to ensure safe operation. Most furnaces sold today will automatically shut down in the event of unsafe operation. But very old furnaces (20 years or more) don’t have many of these controls, and a furnace will continue to operate even though it may be putting large amounts of flue gas into the home.
What does A.F.U.E. stand for, and what does it mean?
This stands for Annual Fuel Utilization Efficiency. It is a rating by percentile for fuel burning furnaces. A 90% efficient furnace is sending 90% of the heat created by the furnace into the home. While 10% of the heat created is going out the flue. The lower the A.F.U.E. is, the less efficient the furnace is.
How concerned should I be about carbon monoxide?
Anything that burns a fuel will create some level of carbon monoxide. This includes gasoline generators, gas and wood fireplaces, gas and wood stoves, your car in the garage, your gas or oil furnace. Every home should have carbon monoxide detectors. Carbon monoxide is a colorless and odorless gas that is harmful in small concentrations and lethal in heavier concentrations. The American Society of Heating and Refrigeration Engineers have said that the highest acceptable level of carbon monoxide short term in a living area is 9 parts per million (or 9ppm). Make sure that your carbon monoxide alarm is capable of detecting low levels.
Should I have my ducts cleaned?
There are several factors that determine if a duct cleaning is necessary. Such as, the material that the ducts are made of. If the ducts are made of the flexible material, there is the possibility that the duct lining can be destroyed by the brushes. This can cause an air quality issue within the home. If the ducts are made of “hard” metal the brushes will not destroy them however, these ducts are sometimes lined with insulation (sometimes call “sound lining”). In this instance the brushes can disturb the “sound lining” and create an air quality issue in the home. When having ducts cleaned, always make sure that you are dealing with a quality contractor with a good reputation. A personal referral is usually your best chance to find a good contractor.
I have a gas furnace, how often should I have my heat exchanger checked?
If a heat exchanger is defective, in most cases it creates a situation where flue gas (containing carbon monoxide) can enter the home. Always have your furnace heat exchanger checked at least once a year. If your heat exchanger is found to be defective, your furnace will be shut down as a safety hazard. It is a good idea to have your furnace inspected in early fall.
Is it okay to run my furnace fan all the time?
If the fan is set to fan “On” the fan will run all the time, regardless of whether the system is heating or cooling the home. This can be a good selection for many reasons. Air is cleaned only when the fan runs, so more fan run time means cleaner air. It is easier for an electric motor to run continuously, rather than start and stop. Running the fan all the time will help to even out hot and cold spots inside your home. It is always okay to run your fan in the “On” position.
Should I invest in a dual fuel, hybrid heat, or geothermal system?
If you are replacing your system, and you are going to be living in the home for a number of years, it is a good option and something to consider. You save money over time, and this system will actually be a cheaper buy in the long term. If you are moving soon, the higher initial cost for the system is not for you.
Why would I need a humidifier for my heating system?
Low humidity levels in the wintertime can cause a number of discomforts. It will cause static electricity, itchy skin, nasal problems, bloody noses, and can also cause wood furniture to dry out and crack. Comfortable humidity levels are between 40-60% relative humidity. Without a humidifier, humidity levels will go as low as 15% relative humidity in the winter. With a humidifier, around 35-45% relative humidity can be achieved. This is going to be a comfortable level. Also, because humid air makes the air feel warmer, the thermostat can be set lower which will save on utility costs.
Outdoor Units (Air Conditioners and Heat Pumps) FAQs
What does S.E.E.R. stand for, and what does it mean?
S.E.E.R. stands for Seasonal Energy Efficiency Rating. This is the rating system for air conditioning operation. The federal government increased the minimum efficiency rating from 10 SEER to 13 SEER in 2006. A 13 SEER model air conditioner is 30% more efficient over the 10 SEER model.
There's a dryer vent close to my outdoor unit, what can I do?
Something should be done, otherwise the dryer vent will put out lint that the outdoor unit will take in and clog the outdoor coil. If we are replacing the outdoor unit we can probably move it away from the dryer vent.
What is an A.R.I. match?
A.R.I. is the Air Conditioning and Refrigeration Institute. ARI is not connected with any equipment manufacturer, and performs independent testing. ARI will certify equipment, and state the level of performance that the air conditioner (or heat pump) meets. If an air conditioner is rated at 13 SEER, ARI has tested it for performance. However, most residences have refrigeration systems that include an outdoor unit and an indoor coil. These two pieces of equipment are designed to work together and achieve a certain level of efficiency (SEER). If we put two pieces of equipment together that are not listed as an ARI match, then we don’t know how the system will perform. It is vital that equipment be matching.
Every year I have to add refrigerant to my system, can I charge the refrigerant myself?
Purchasing refrigerant requires a refrigerant license provided by the Environmental Protection Agency. Additionally, to work on HVAC equipment a person must be supervised by a licensed technician or have a state issued license.
How often should I have to add refrigerant to my system?
Your refrigeration system shouldn’t need refrigerant, unless there is a leak. There should not be any leaks, especially if the system is new. The refrigeration system is designed to be completely sealed. The refrigerant does not burn up or just go away. It does evaporate, but then condenses inside the system, and repeats this cycle. The only reason that you might need refrigerant is a leak.
Will the newer refrigerant cool my house as well?
R-22 (Freon is a brand name) is the older refrigerant that is being phased out. R-410a (sometimes called Puron) is the newer refrigerant and works in the same manner that R-22 does. The difference is in the chemicals used to create the refrigerants. The R-410a refrigerant does not contain a chlorine atom, making it better for the ozone. Both refrigerants work equally well for comfort cooling.
Can I get a new A/C (or Heat Pump) with a larger cooling capacity?
When a residence is being built, a heat load (Manual J) calculation is performed to determine the heating and cooling system capacity needed for the residence. It is a very specific calculation that takes into account hundreds of different factors. If a system is oversized or undersized it can cause serious problems for the residence. If an air conditioner is oversized, it will cool down a home too quickly and not have time to dehumidify, causing high humidity and sometimes mold and mildew problems. If the system is undersized, it will dehumidify very well, but have a hard time lowering the temperature in the home. System size is very important. If we wanted a larger cooling capacity, this might be okay with a two-stage air conditioner. A two-stage air conditioner has two different cooling capacities operating in either high stage or low stage. If the two-stage air conditioners low stage has a lower cooling capacity than the old air conditioner, but the high stage is a higher cooling capacity, then this would be okay. This would be a good solution for a home that could never reach a comfortable temperature in the summer.
Why is my house so humid in the summer time?
Normal humidity levels for a house in the summer are between 45-60%. If your home is not within this range something is not working properly with your cooling equipment. Your system could be oversized, your condensate drain could be clogged. Your indoor blower fan could be set too high. If your indoor relative humidity is over 60%, this is a problem that should be addressed. It may be possible that your home may need a whole-house dehumidifier. But it’s probably best to have a routine check-up performed to ensure proper operation of the cooling system.
What is the difference with the new (R-410a) and old (R-22) refrigerant?
The difference is in the chemicals used to create the refrigerants. The R-410a refrigerant does not contain a chlorine atom, making it better for the ozone. Both refrigerants work equally well for comfort cooling. Refrigeration systems contain oil to lubricate the compressor. The oils that are used for the refrigerants are different, and cannot be mixed. So if someone is switching out equipment at your house, make sure that they are flushing the refrigeration lines (if they’re not replacing them).
What does H.S.P.F. stand for, and what does it mean?
H.S.P.F. stands for Heating Seasonal Performance Factor. It is the standard of efficiency for heat pumps in heating mode.
Should my outdoor unit (A/C or Heat Pump) be on, or above the ground?
If your outdoor unit is a heat pump, a good rule of thumb is that it should be elevated above the ground for the average annual snowfall. Example: if it snows on the average four times a year, for a total of twenty inches, your average annual snowfall is five inches. In the Washington D.C. area, heat pumps are generally elevated six inches. If your air conditioner is in a mulch bed, or is exposed to being damaged in any way, it is a good idea to elevate it as well.
How does a heat pump bring heat into the house in the wintertime?
Just as an air conditioner removes heat from your house in the summer. A heat pump reverses the cycle in the winter and begins absorbing heat outside and pumping it into the house. Although it may feel cold outside, there is heat in any substance down to -460 degrees. There is plenty of heat outside to be absorbed. However, because water freezes at 32 degrees, the outdoor coil will freeze, and then have to be defrosted. Making the heat pumps operation less efficient.
Does it really matter if my equipment matches?
It is important that your equipment matches. The Air Conditioning and Refrigeration Institute (ARI) performs independent testing on HVAC equipment. ARI will certify the equipment and state the level of performance the air conditioner or heat pump meets. The outdoor unit and indoor coil are designed to work together. If these pieces of equipment are not listed as an ARI match then we don’t know how the system will perform.
Is there any way that I can relocate my outdoor unit to another side of the house?
Relocating an outdoor unit can be done. There are a few factors to consider first, due to the fact that new refrigerant lines would have to be run. These new lines would either have to be run around the outside of the house or more easily (and more appealing to the eye) through an unfinished basement or attic.
I want to build a deck over my outdoor unit, is that a problem?
When building a deck above an outdoor unit, it should be at least 6-8 feet above the unit to allow for proper airflow. If airflow around the outdoor unit is restricted, it will diminish the unit’s ability to remove heat from your home. The equipment literature should have the specifications on the required clearances.
Are electronic air cleaners better than a media filter?
An electronic air cleaner is designed to magnetized dust and dirt that cause it to adhere to the air cleaner cells. As dust and dirt is built up on the air cleaner the magnetism once created is lost. As an electronic air cleaner operates, it’s filtration rating actually decreases. A standard media filter is a barrier that air has to pass through, with the idea that air will pass through but dust and dirt will not. A media filter’s filtration rating actually increases with usage. The buildup of dust and dirt on the media filter help to collect more dirt and dust. High efficiency media filters are a good choice to clean the air in your home, when compared to electronic air cleaners.
What does M.E.R.V. stand for, and what does it mean?
The American Society of Heating and Refrigeration Engineers developed a standard and rating system for filters. It is the MERV scale. MERV stands for Minimum Efficiency Reporting Value. The MERV scale goes from 0 (which would be no filter) to 16 (the highest rating possible). Blue spun fiberglass filters (the ones that cost about 65 cents at the hardware store) have a rating of about MERV 1. Electronic air cleaners are about a MERV 8, while a lot of the high efficiency media filters have a rating of about MERV 12 or 13 (hospital quality air).
Would I benefit from a high efficiency air cleaner?
Yes, unless you already have one. Having a good filter in place will keep your blower motor, blower wheel, and indoor coil clean. Using a good high efficiency filter will help to keep your system operating at peak capacity, and prolong system life. The purpose of the filter is to provide clean air to the equipment. The fact that this same clean air is then provided to your home is an additional benefit.
How often should I change my air filter?
This depends on the type of filter that you are using. An electronic air cleaner should have its cells cleaned at least once a month. Washable filters are not recommended, but if you have one, it should be cleaned at least once a month. We recommend standard high efficiency media filters. If you have a one-inch thick pleated media filter, it probably needs to be changed every 1 ½ – 2 months. If you have a four-inch thick pleated media filter, it probably needs to be changed every 6 months.
What direction doe the arrow on my filter go?
The purpose of the filter is to provide clean air to the equipment. To provide clean air to the equipment, the filter must be before the equipment. The arrow on the filter is showing what direction the air should flow through the filter. The arrow should always point into the equipment, which is the direction of the airflow.
Are washable filter worth the money?
Washable filters are not recommended. Most of the time a washable filter is too dense and is too restrictive of the air flow through the system. Also, a washable filter collects dust and dirt, which we are then supposed to wash out. This works better in theory than in practice. The dust and dirt that is collected on the washable filter is not completely removed when cleaned, this means that the filter becomes more and more restrictive over time.
About COTC Mechanical
Northern Virginia’s residential, commercial and precision cooling experts. Learn more about us.