Here are some of the more frequently asked questions we receive. If you do not find your
question answered here, please use this form to
Ask A Tech
your question.
My system isn’t working. Is there anything I can do to fix it?
You should check your filter and make sure it is clean. Clogged filters
reduce the amount of air flowing through the system and reduce comfort
and efficiency.
Make sure that the circuit breakers for the system are on. If there is
a sight window on the unit look inside and note any fault codes (count
the flashing lights- on some models there is a number of short flashes
followed by a number of long flashes). Turn the breaker off then back
on to be sure it is reset.
Make sure the thermostat is set properly. The SYSTEM switch should be
set to the desired mode(HEAT, COOL or AUTO) and the thermostat setpoint
should be above room temperature for heat or below room temperature for
cooling. Most digital thermostats have a several minute time delay before
the equipment comes on.
If you have checked these items and the equipment is still not working,
turn the system off and call for service.
The air coming from the registers feels cool when my heat pump is set for heating. Is there a problem?
While a heat pump is perfectly capable of effectively heating your home,
the temperature of the air coming out of the registers confuses some people.
The air is heated to about 90 to 95 degrees, depending on the outdoor temperature.
This temperature is approximately 20 to 25 degrees warmer than the indoor air
temperature and will warm your house. It is, however, below body temperature (98.6
degrees) and can feel cool when someone puts their hand in the airflow.
Which type of filter should I use?
Most residential units come with a 1" disposable type filter. The low cost
disposables made of spun plastic mesh are only 3 to 5 percent efficient.
Most of the dirt goes right through them. The pleated cloth type filters
are around 40 percent efficient and trap dirt much better. Some pleated
filters claim that they are good for 3 months. However, most will need to
be changed more often, especially during peak usage in summer and winter.
Is it better to let the system wear out completely before replacing it, or to replace it at some point before it wears out?
You will probably save money by replacing your old system before it wears
out. That's because today's generation of central air conditioning systems
and heat pumps are so much more energy efficient than their older counterparts.
The efficiency of a central air conditioner is indicated by its Seasonal Energy
Efficiency Ratio or SEER. The higher the SEER, the more efficient the unit. The more
efficient the unit, the less electricity needed to operate it.
In recent years, manufacturers of air conditioners and heat pumps have made dramatic
progress in increasing the SEER of their units. As a result, it may make economic
sense to purchase a new, more efficient unit now and immediately lower your operating
costs.
Eventually, the more efficient unit will pay for itself through decreased utility
bills. In the meantime, you'll gain the added benefits of greater reliability and
longer warranty protection.
Another benefit of a higher efficiency unit is a lower life cycle cost, which is the
total of the operating and maintenance costs over the life of the system.
Trane Home Comfort Institute experts explain that a system with a higher SEER may
have a higher purchase price than one with a lower SEER. However, because of its
higher efficiency, it will use less energy to cool your house, resulting in lower
electric bills. In many cases, these savings are more than enough to offset the
additional cost of the higher SEER unit.
Should I purchase a system with the new "ozone safe" refrigerant?
Absolutely. The cost of Refrigerant-22 is going to rise dramatically in coming years
as it is phased out of use. The cost of Refrigerant-410a will fall as more and more
equipment enters the market. The new refrigerant and the equipment utilizing it have
been working reliably for over 10 years now. The warranty failure rate on equipment
with the new refrigerant is notably lower than with the old, due in part to extensive
training associated with the transition. Best of all you know you’ve done your part
to help preserve the environment!
Should I set my FAN to Auto or On?
This is, to some degree, a matter of personal preference. Running the fan
continuously can help even out temperature variation throughout the home.
It can also provide constant filtration, purification and humidification if
your system is fully equipped. During the Heating season some may not like
the "drafty" feel of the air movement. Some people don’t like the airflow
noise etc. Try it both ways and see how it affects your environment and your
comfort.
Note: If your ductwork is in an attic or crawl space you may want to use
Auto mode. Since the ductwork runs through an unconditioned space some heat
will be lost or gained through the duct. In other words, with only the fan running,
the air in the duct will be heated slightly as it passes through the hot attic
duct in the summer. The reverse will occur as air passes through the cold attic
duct in the winter. This can lead to higher energy usage.
What is a S.E.E.R. rating?
When purchasing a car, smart buyers usually check the miles-per-gallon
rating.
When purchasing gasoline, they check the octane rating.
And, when purchasing a central air conditioning system, they check the
SEER rating.
The what?
The SEER, or Seasonal Energy Efficiency Ratio, rating. Like its "mpg"
counterpart in the automotive industry, the SEER gives an indication of
the performance efficiency of the system. The higher the SEER, the more
efficient the unit. And, the more efficient the unit, the lower the
operating costs.
The air conditioning industry originally used an Energy Efficiency Ratio
or EER to rate efficiency. This was a simple mathematical ratio of cooling
output versus electrical power input.
Recently, however, the U.S. Department of Energy developed a more sophisticated
test method that rates the performance of a unit over a wide range of operating
conditions. The result -- the SEER -- is indicative of the unit's operation
throughout an entire cooling season.
Bear in mind, however, that SEER ratings compare equipment only. Many other
factors, including how you use your home and the condition of ductwork, affect
energy use. That's why it's important to have a competent air conditioning
dealer visit your home and evaluate your entire system.
It's also important to remember that the rating of an outdoor unit is based
on a matching indoor component. As a result, if you replace an outdoor unit
without replacing the indoor unit, you're not likely to get the efficiency
you expect.
By purchasing a system with a high SEER, you'll use less energy to cool your
house, resulting in lower electric bills. In many cases, these savings are enough
to partially or fully offset the cost of the new equipment within a few years.
You can also check with your local utility about a possible rebate. Many utilities
offer such programs based on the unit's SEER rating and cooling capacity. In most
cases, the higher the SEER rating, the higher the rebate.
Why should I purchase a Service Agreement?
Your Heating and Air Conditioning system is the most expensive appliance
in your home. It is also the most costly to operate and to repair. Studies
have shown that systems which have regular maintenance consume 10-15 percent
less energy than those which do not. So regular maintenance can actually pay
for itself in reduced utility bills. Keeping all of the critical components
clean and properly adjusted will also help extend the life of your equipment
and reduce the chances of costly breakdowns. We also offer discounted repair
pricing and priority scheduling for our Service Agreement customers.
How does air conditioning work?
An air conditioner makes your home cooler, true. But in terms of how the
system actually works, it's more accurate to say that an air conditioner
makes your home less warm. What it's really doing is drawing heat energy
out of the house and transferring that heat to the outdoors.
- A cool gas (the refrigerant) flows into the compressor, where it is compressed into high temperature, high pressure gas. The compressor pumps this hot gas through the tubes to . . .
- The condenser coil in the outdoor unit (also called the condenser.) As the hot gas passes through the condenser coil tubes, heat is transferred from the gas, through the metal fins surrounding the air. This causes the gas to cool and condense into liquid. A motorized fan forces air across the condenser metal fins to increase the rate at which heat is transferred. Meanwhile...
- The liquid refrigerant flows through tubes to the evaporator inside your home. Once inside the evaporator, the refrigerant goes through a pressure reducing device that causes the refrigerant to quickly expand and to cool rapidly. Then the cold refrigerant travels through the tubes of the evaporator coil where it absorbs heat energy from the surrounding air and turns back into a gas (it evaporates). Also, humidity from warm moist indoor air condenses on the evaporator and drains away. Meanwhile...
- A blower draws warm air from the house, moves it through the evaporator where heat energy is removed and blows this air on through the ductwork into your home -- cooler, dryer and altogether more pleasant. From there...
- The cooler gaseous refrigerant travels through tubes back to the compressor where the cycle begins again.
So you see, that air blowing out the top of your outdoor unit is so hot because it contains heat energy that was inside your house just a couple of minutes before.
Should I worry about Carbon Monoxide?
If you have gas appliances in your home you should be aware of Carbon
Monoxide (CO). CO as it is known, is an odorless colorless gas that is
produced when a fuel is burned. CO is poisonous and can cause severe
illness and even death. The only way to know when CO is present in your
home is to install a CO Detector. We recommend that any home having propane,
natural gas or oil appliances have AT LEAST one Carbon Monoxide detector.
Having your heating system checked yearly is a very good start, but that
alone does not guarantee that you and your family are safe. Changing conditions
in the equipment or weather can cause an unsafe condition to occur at any time.
Only a quality CO Detector can continually monitor the air inside your home and
alert you when an unsafe level is present. For more information call us at 703-541-1006
or e-mail us at
northstar@northstarac.com.
What is duct cleaning?
Duct Cleaning is the process of removing the dust, dirt and debris from
the inside walls of your heating and cooling systems ductwork. Many homeowners
who pride themselves with having clean homes would be horrified if they could
see the inside of their ductwork. Because it is out of sight, the ductwork is a
frequently overlooked location for allergy and odor causing contaminants in your
home. During construction, renovation and with normal use over time dirt and
contaminants collect inside the duct system.
In order to remove this build up a large vacuum is attached to the duct
work near the air handler or furnace inside. This vacuum will collect the
debris and remove it from the system. Once the vacuum section is hooked up
high pressure air is run down the individual duct runs pushing the debris
toward the vacuum. This procedure is done for both the supply (outlet) ducts
and return (inlet) ducts. A good duct cleaning will include the blower section
of the heating and cooling equipment.
There are many types of duct cleaning equipment and methods to get the job
done. The type and condition of the duct will determine which methods of
cleaning are used.. Some ducts need a soft "scrubber" attachment that
rotates and physically cleans the duct walls. Some ducts can be cleaned
with a high pressure head that "beats" the duct walls to knock debris loose.
Duct work with biological growth may need a "biocide" treatment to ensure
proper cleaning and no re-growth.
Prices and job quality are all over the spectrum when it comes to duct
cleaning. Be sure that a complete and thorough job is done. Ask if they
can provide before and after images of your ductwork so you can visually
see the difference. Be careful of the ultra-low price come-ons. There is
only so much time you can spend on a job for $49.95. I would look for truck
mounted equipment. The tremendous amount of suction generated by the truck
powered vacuum will ensure that any dirt that is loosened in the duct will
be safely removed from the house. If the dirt is loosened from the duct wall
and not removed, it will be spread around your home the first time your system
fan comes on. Remember the object is dirt removal, not dirt redistribution.
What is indoor air quality?
What is indoor air quality? Well, it’s just that, it is the quality of the
air that we breathe when we are indoors. This includes the quantity and
type of particles in the air, as well as the humidity and freshness of the
air. All of these things can be controlled and improved through your heating
and air conditioning system.
Every system has a basic air quality component called a filter. Most one
inch filters are very inefficient and trap only a small percentage of the
largest particles passing through the system. So when you look at that dirt
on your filter, realize that what you are seeing is at best 5% of the visible
size dust that went through it! Almost all of the particles that cause asthma
and respiratory stress are too small to see. Most irritants, such as dust mites,
pet dander and pollen are microscopic. So, as you can see, standard filters are
no help in relieving allergies or asthma symptoms.
The best way to remove these small irritants is with an Ultraviolet Air
Purifier and a Whole House Air Cleaner. This is the only comprehensive way
to reduce airborne causes of allergy and asthma symptoms! The Ultraviolet
air purifier will kill mold spores, viruses, bacteria, and dust mites as
they pass by the light in the airstream. This will keep the little critters
from multiplying, but it does not remove them from the air that you breathe.
That’s where the Whole House Air Cleaner comes in. After they have been killed
by the Purifier, the Air Cleaner captures them and the process is complete.
Other worthwhile components include humidifiers and fresh air ventilators.
Humidifiers maintain a healthy level of moisture in the air that you and
your family breathe. This can help alleviate dry and scratchy throat,
nosebleeds and dry, chapped skin. In many cases you can also lower your
thermostat a degree or two because higher relative humidity makes you feel
warmer! Fresh air ventilators help by bringing in a certain amount of fresh
outdoor air into your home, while simultaneously exhausting stale indoor air.
The intake air and exhaust air are passed through a heat exchanger to recover
as much heat as possible between the two airstreams. Its like having an open
window without paying to "heat the neighborhood". This dilutes the contaminants
that tend to accumulate in our homes when the windows and doors stay closed for
long periods during the peak seasons.
What is SEER and HSPF?
When looking at a new system, remember that the efficiency of a heat pump
is indicated by two ratings, one for heating and one for cooling. The
heating rating is called the Heating Seasonal Performance Factor (HSPF),
the cooling rating is called the Seasonal Energy Efficiency Ratio (SEER).
In both cases, the higher the number, the greater the efficiency and the
lower the operating costs.
What is the difference between electronic and media air cleaners?
The two primary types of Whole House Air Cleaners are the Electronic type and Mechanical or
Media type. Both have good features and benefits. Which one is right for your home depends
upon your individual needs and your equipment type and configuration.
An electronic air cleaner uses an electrical field to charge small particles in the air as
they pass through the filter. Once the particles are charged, they then pass through a
collector grid with the opposite polar charge. This makes the dust and small particles
stick to the collector like a magnet. Electronic units usually have a pre-filter to catch
the larger particles before they enter the charging field. These filters have an excellent
capture rate if they are properly sized, installed and maintained. They do not require filter
replacement, but they do require regular maintenance. The collection efficiency falls as the
collection plates become coated with dust. The pre-filters and collection cells need to be
removed and cleaned regularly to maintain efficiency.
A mechanical or media air cleaner uses a tightly woven material to physically trap dust and
small particles. The collection rate of small particles is typically less than that of an
electronic type, but media type filters require much less maintenance. The media is usually
pleated to extend the surface area of the filter material. There is nothing to clean with
these filters, but the media will need to be replaced typically once or twice per year
depending on usage and conditions in the home. Unlike electronic types, media type filters
actually become more efficient over time. Of course, once they become "clogged" they will
begin to reduce airflow through the system as they become too restrictive.
Which one is right for you and your home? Give us a call and we can help you decide. There
are many ways to improve the quality of the air inside your home. Let NorthStar Heating & Air
Conditioning show you how to breathe easier today!
How does a UV Light Work?
Ultraviolet Air Purifiers are a great addition to any home comfort system. From
controlling odors to killing harmful airborne contaminants, your home will be a
fresher, more healthy environment. The principle behind UV air purifiers is simple:
High intensity Ultraviolet light is harmful to living organisms. UV technology has been
used in food processing and water treatment for years. The only maintenance required is
to replace the bulb once per year.
There are two primary uses of UV lights in HVAC systems. The first is for control of
biological growth on surfaces. An ultraviolet light placed above your evaporator coil
will kill and prevent re-growth of mold and bacteria on the surfaces of the evaporator
and drain pan. This is a common place for these things to grow as it is normally cool,
dark and damp. This is known as coil irradiation and is very effective.
The second type is for control of airborne biological particles. These would include dust
mites, mold spores, bacteria and viruses. As airborne bacteria, viruses and dust mites pass
by the light in the duct they receive a lethal dose of UV radiation. One thing to consider
when using this type of approach is the "kill zone" around the light. The intensity of the
light diminishes at the square of the distance. In other words, only the particles passing
close to the light will receive a lethal dose of light. For this method to be effective you
will likely need two or more lights in your return air duct.
Both types of lights can also be "ozone generating" or "non-ozone generating". An ozone
generating light produces small amounts of the gas which acts as a natural odor neutralizer.
This is a matter of personal preference and can usually be switched back and forth by
changing light bulbs.
What is an Economizer?
Economizers are primarily used on Commercial Rooftop Equipment. During mild outdoor
weather in the Spring and Fall many commercial spaces still require air conditioning.
The heat generated by lighting, computers and office equipment can make it hot inside
even when it is 45-70 degrees outside. An Economizer senses the temperature and humidity
level of the outdoor air. If the air is cool and dry enough for air conditioning use
then the compressor is not used to cool the space. Instead, an opposed blade damper
simultaneously closes off the return duct and opens a damper to the outside air. By
doing this you are not paying to mechanically cool the space. You’re simply using the
system fan to pull in cool, dry outdoor air for free! These accessories typically save
10 to 15 percent on annual cooling costs. If you are replacing your rooftop unit, and
will be using the space for two years or more an economizer is a good way to offset
rising utility costs.
What is a Heat Recovery Ventilator (HRV) and how does it work?
A Heat Recovery Ventilator (HRV) is a device that serves a purpose opposite of that of
economizer: it allows to dump the stale indoor air and accept fresh
outdoor air without losing as much energy as you would if you just opened a window.
This is important in tight new houses to prevent indoor pollutants from reaching
unhealthy levels.
A typical HRV uses two fans, one to expel household air and the other to
bring fresh air in. The key feature of an HRV is its heat-exchange core,
which transfers heat from the outgoing stream to the incoming stream in the
same way that a car radiator transfers heat from the engine's coolant to
the outside air. The heat-exchange core is usually made up of multiple
plates of aluminum or plastic separated by narrow passages through which
incoming and outgoing airstreams flow. As the streams move through, heat is
transferred from the warm side of each passage to the cold, without the airstreams
coming into direct contact.
Depending on the model, HRVs can recover up to 85% of the heat in the
outgoing airstream, making them far more energy efficient than letting air
in and out through windows. In addition, an HRV filters the incoming air to
trap particulates such as pollen or dust.
Although an HRV can be effective in the summer months, when it takes heat
from incoming fresh air and transfers it to stale, air-conditioned exhaust
air, it's most important use is in colder climates during the winter. A
potential problem is buildup of frost inside the exchange core if temperature
falls below about 20° F. To avoid this, a damper closes off the incoming cold
airstream and routes warm air through the core. After several minutes, a timer
opens the fresh-air port and allows ventilation to continue.
A typical HRV for residential use might move as much as 200 cubic feet
(5.7 cubic meters) per minute of air, but the fan speed can be set to suit
the air quality in the home. For example, a slow to medium fan speed may be
adequate for normal living, while a house full of guests might require the
highest setting. Controls are available for intermittent and remote operation.
HRVs only move the heat associated with air temperature difference. See the
ERV section for more on this.
What is an Energy Recovery Ventilator (ERV)?
An Energy Recovery Ventilator (ERV) is a device that does a similar job to an
HRV,
but handles both the heat from air temperature and moisture in the air (known as
sensible and latent heat.) Because it exchanges both, they are usually more efficient
and do not have condensation problems that can occur in a HRV. There are two types of
ERVs, linear exchangers similar to HRVs and rotary wheel type systems where media
moves between the air moving in and moving out to transfer the heat and moisture.
What is an Air Balance / Airflow Analysis?
Air Balancing is the process of testing and adjusting your air conditioning system to
deliver the right amount of air to each room in your home. The actual Air Balancing
process includes a number of related tests that determine the performance of your air
conditioning and heating system. Air balancing hoods are used to measure the amount
of air at each grille. Manometers measure system pressures. Hygrometers measure system
temperature and humidity. The results of all these tests are compiled into a report to
determine how well your system is functioning.
Can any system be air balanced?
A contractor with the right tools and training can improve the performance of
virtually any system. The more accessible your ductwork is, the easier it is to
perform balancing and duct renovation work.
How will air balancing solve my problem of rooms with different temperature?
The airflow through the system is what carries the heating or cooling. By adjusting
the volume of airflow, we adjust the amount of heating or cooling a room needs to
become comfortable.
What's the difference between an NCI Certified Technician and other heating and air conditioning techs?
Most companies are in business to just fix or replace heating and cooling equipment.
Your certified Air Balancing Technician considers the entire system and is qualified
to test, diagnose, and repair your ducts as well as your equipment.
Most contractors tell me that I'll save big on my utility bills and be more comfortable by just replacing my existing equipment with a more efficient model. Is this true?
It could be, as long as the duct system is in the same condition as the new
equipment. If it isn’t, the system will only function as well as the ducts do.
Compare it to installing a brand-new race car engine on an old beat up sedan.
What is an equipment survey?
If you request a quote to replace a system, or to place equipment under a
maintenance plan, we will likely need to perform a survey. A survey is
simply a visit by one of our sales or technical staff to llok at your
equipment and to assess your individual needs. We will likely collect
information such as model/serial numbers on equipment, filter and belt
sizes, water availability for cleaning, any unusual access conditions or
features on equipment, and general condition of equipment. This way we are
fully aware of what your needs are before we quote a price on a product or
service.
What is combustion efficiency?
Combustion efficiency is a calculation of how well your equipment is burning a specific
fuel, shown in percent. Complete combustion efficiency would extract all the energy
available in the fuel. However 100% combustion efficiency is not realistically achievable.
Common combustion processes produce efficiencies from 10% to 95%. Follow this link for a
more detailed explanation of
combustion efficiency.