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How Rain & Flooding Affects Your HVAC System

Written by analytics@markalon.com on . Posted in Maintenance. No Comments on How Rain & Flooding Affects Your HVAC System

Heavy rains in Middle Tennessee serve as a reminder of the dangers posed by excessive water.  Flooding of roadways and fallen trees come to mind, but have you considered how excessive rain can affect your heating and air conditioning system? The typical central heating & air-conditioning system has 3 main components:

  • an outdoor part – which sits beside or behind your home,
  • an indoor part – usually in a basement, attic, or utility room, and
  • ductwork – which runs all around various spaces inside your home.

Let’s look at how heavy rains can affect each of these.

Outdoors

The outdoor parts – the compressor and condenser coil – are built to withstand all kinds of weather.  The sensitive electrical components are sealed and the connections are insulated and made impervious to moisture. The outer-facing parts are comprised of aluminum, copper, and other metals, which are made to handle heavy rains.  But too much rain can impact the outdoor unit in the following ways:

  • Erosion, gullies, and mudslicks can cause the pad the outdoor unit is sitting on to shift as the heavy rain washes away the earth beneath and beside it. The result is that the unit is no longer level, or in extreme cases, the unit has washed partly or completely off the pad. If you encounter either of these situations, turn the unit off and do not operate it until the unit is made level again, on a firm footing.
  • Debris from the yard or blowing in the wind can wash up near the unit or become lodged in the unit. Branches, leaves, and other debris can fall inside the unit (where the fan blades are), or can damage the fins on the sides of the unit. After a storm, always check the outdoor unit. If the fins have been damaged or you see gashes or holes, turn the unit off and call a professional. Operating the system with debris in or against the unit will cause damage to the unit!
  • Standing water or flooding around the outdoor unit can be quite serious, as it may have damaged the internal components. Turn the unit off and have it professionally inspected before you restart it. In the meantime, check the source of the water: do you have a broken or blocked gutter or a downspout that needs to be re-directed? If the source of the standing water is due to the unit being located in a low spot in yard, or in an area with poor drainage due to vegetation or slopes, consider relocating the unit or raising it up several feet to prevent future flooding.
  • Tip: Never use a tarp or plastic bag to cover the outdoor unit. It traps moisture inside, leading to rust, mold, and mildew, which weakens the components and will cause them to break down sooner. It also creates an attractive nesting ground for insects and vermin. Covering the outdoor unit while running the air-conditioner will damage the compressor.

Indoors

The indoor part – typically the furnace, heat exchanger, evaporator, and air handler – is usually located in a basement, attic, or utility room. Because it is designed to be indoors, its electrical components and construction are not built to withstand rain or extreme moisture. In a heavy rain, or even during a water heater mishap, your basement or utility room may experience flooding. If your unit is located in the attic, be mindful that a roof leak as a result of the heavy rain could develop. Any time your indoor unit is wet or encounters standing water, a short in the electrical circuits can damage the wiring, motors, and electronics, and make the system hazardous. The system should be turned off from the main circuit breaker (not just at thermostat). Do not attempt to start it again without having it thoroughly inspected by an HVAC technician.

Ductwork

Ductwork, which is often run in crawlspaces and attics, can be impacted by heavy rains. If your crawlspace floods or your roof leaks, the ductwork will get wet. Ductwork is typically not waterproof. Water entering the ducts may remain inside the duct long after the flood itself has receded, and will cause the ductwork to deteriorate. Mold and mildew will begin growing inside your ductwork, giving your whole house a musty smell, and could lead to the perfect environment for toxic mold growth. Roof leaks can often go unnoticed in the attic for some time, and moisture or even standing water in a crawlspace can go unnoticed if it doesn’t raise to the level of impacting the floors. This ongoing moisture will saturate the insulation around the ducts, in the attic, and under the floor joists. Wet insulation no longer does its job, and the increased heat transfer causes your heat and air conditioner to run longer cycles to compensate, or forces you to continually adjust the thermostat to compensate for the reduced efficiency.  But the biggest danger to you and your family from wet ductwork is the reduced air quality and health hazards of mold.

If you are concerned that your system is not working properly due to recent storms in the area, give Interstate AC Service a call at (615) 832-8500. We’ll determine if your system is safe to operate or is in need of repairs.

Is Your Thermostat the Cause of Your Heating Problem?

Written by analytics@markalon.com on . Posted in General Advice. No Comments on Is Your Thermostat the Cause of Your Heating Problem?

It’s cold and your heat doesn’t seem to be working!  Did you know your thermostat could be the cause?  Here are some troubleshooting tips and fixes you may be able to do yourself, to save time and money.

  • Power:  Is the display on your thermostat blank? It could be there is no power to the thermostat.  A tripped circuit breaker or fuse could be the problem, possibly caused by a power outage, power surge, lightning strike, or storm. Reset the tripped circuit breaker or replace the fuse. Make sure all the wires going to the thermostat are connected and not loose.
  • Batteries: If your thermostat is battery-powered, or relies on battery for backup power in case of a power outage, it could be that the battery needs replacing.  If you have a programmable thermostat, and had a recent power outage, it could be that without a functioning battery backup, all of your settings have been wiped out by the power outage and the thermostat reverted to its default program. You’ll need to insert a new battery, then re-enter your settings.
  • Date/Time: Check that the thermostat is set to the correct day and time, including the AM or PM designation.  One customer bought a programmable thermostat to save money, with the intent to have the heat backed down while the customer was away at work, and have the heat cranked up at night when the customer was home.  But when the customer started freezing at night, they mistakenly thought something was wrong with their heat, when the real culprit was they had the AM/PM designation backwards on their thermostat!

Here’s a tip: If you’ve lost your owner’s manual for your thermostat, most major-brand manuals can be found on the web — just go to the manufacturer’s web site.

  • Mode: Check that the thermostat is in heat mode. This switch can easily get accidentally bumped into the off or cool position. If it’s a programmable thermostat, switch it to manual control and set it for 5 degrees above the room temperature, and wait to see if the heat cycles on.  If it does not, then the problem may be at the furnace.

If none of these DIY fixes addresses your problem, and you live in the Nashville area, give us a call at 615-802-2665. We’re here to help!

Single vs Variable-Speed Blowers: Does it Matter?

Written by analytics@markalon.com on . Posted in General Advice. No Comments on Single vs Variable-Speed Blowers: Does it Matter?

Single-Speed Blowers

If your furnace or heat pump is more than 10 years old, it likely has a single-speed air handler (blower).  Single-speed blowers work like a light switch: they’re either on (blowing at maximum speed) or off (not blowing).  Single-speed units have been the standard, most affordable option, but they have some disadvantages.

Disadvantages of Single-Speed Blowers

  • It uses more electricity.
  • It causes large swings in temperature: from too cold to too hot. And because the air does not circulate at all when the blower switches off, the heated air rises to the ceiling.  This is why we recommend running ceiling fans on low, even in the winter.
  • When the blower comes on, you hear a loud rush of air and it can be noisy.  Plus, the surge of electricity it consumes may cause your lights to dim for a second each time it kicks on.
  • Because there are periods when the blower is not blowing at all, humidity control suffers.  In the summer, the air only moves through the de-humidifier when the blower is on (actively blowing), and humidity builds up when the blower cycles off.
  • The constant cycling on and off makes for more wear-and-tear on all the components, and could cause the system to breakdown sooner.

​Variable-Speed Blowers

Over the last 10 years, technology has continued to advance, making variable-speed motors less complex, more reliable, more responsive, and more commonplace on HVAC units.  A variable-speed blower runs at different speeds to precisely control the flow of heated or cooled air throughout your home.

On a mild day, the blower runs slower.  The AC or heat runs in longer cycles so the indoor temperature does not spike up and down, thus making overall efficiency higher.  Variable-speed blowers offer the highest efficiency and performance.  The AFUE (annual fuel utilization efficiency) of a furnace with a variable-speed blower may be as high as 95%.

Advantages of Variable-Speed Blowers

  • Sensitivity: Since it operates at different speeds, it can adapt to the unique airflow requirements of a home at any given point in time.  For example, it can compensate for the amount of dirt in the air filter or blocked vents by increasing the fan speed.
  • Efficiency: It always operates at the lowest speed required, thus it saves electricity, and is less costly to operate. This increases efficiency and allows the unit to use about two-thirds less electricity. This results in a 40% year-round energy savings (about 75% of that savings is in heating).
  • Quieter: Whether running AC or heat, the unit is quieter because most of the time it is not operating at full speed. Plus, it gradually ramps up to full-speed when needed, eliminating the sudden noisy blast of air common with single-speed units.
  • Comfort:  A variable-speed unit will keep you more comfortable because it keeps the temperatures more constant – eliminating the wide swings of too cold and too hot which results from single-speed systems cycling on and off.
  • Air Circulation:  It circulates air continuously, with fewer “off” cycles, allowing more air mixing and preventing the trapping of hot air near the ceiling.  In the summer, it allows the air-conditioner to remove more moisture from the air, decreasing humidity to make you feel more comfortable.
  • Air Quality: Because your air filter is only filtering particles when the air is moving through it, having a variable-speed blower means more air will be filtered.  This means leaving fewer particles to be deposited in your living space, which may translate into fewer allergens and less dust.
  • Longer Life: Since a variable-speed blower is not having to constantly cycle on and off, there is less wear-and-tear and thus fewer breakdowns and a longer operating life for the system.
  • Payback: Although the tax credits have expired for buying a high-efficiency variable speed HVAC unit, it is still a wise purchase.  This is because the reduced costs (less electricity consumed, fewer breakdowns) during operation mean you’ll get a return on investment (ROI) in just 4-5 years.

Does it Really Matter?

Bob, a homeowner who recently had a variable-speed HVAC system installed, says “There is a big difference… it does a better job of keeping warm and even throughout the room.”  His old system was quite noisy, so that has been a big improvement, too.  One feature Bob likes about his furnace now is that “it waits until the furnace is warm before it starts to blow hard.”

What System is Right for You?

If you live in the Nashville TN area and need help deciding between the various types of systems on the market and determining which one is best for your needs, give us a call at (615) 832-8500.

Common AC Problem: Inadequate Cooling

Written by analytics@markalon.com on . Posted in Air Conditioning. No Comments on Common AC Problem: Inadequate Cooling

During the summer, your air conditioner (AC) works harder and longer. That high demand may cause a problem to rear its ugly head.  In this multi-part post, we’ll take a look at some of the most common AC problems, talk about the possible causes, and provide suggestions for tackling each problem.

Inadequate Cooling

If your system is working fine (no leaks or noises, etc.), but it is not able to maintain the desired temperature you set on the thermostat, especially during the hottest part of the day, it could be that your unit is under-sized for your house. Perhaps you added space on to the house since it was built or removed trees near the house that were providing shade. When excessive demand is being made on the unit and it can’t keep up, you may need a larger unit. To delay having to get another system, you can add extra insulation – especially in the attic – and get double or triple paned windows with low E glass, to help improve your system’s performance. Getting regular tune-ups in spring and fall also helps to maintain your system’s efficiency so it will operate at peak performance. Other reasons for inadequate cooling include:

  • A dirty condenser or evaporator coil
  • A blocked condenser
  • Clogged drain lines
  • A lack of system refrigerant

Avoid AC Problems

Summer can be the best time of the year, so don’t let air conditioning problems hinder you from enjoying it.  Be sure to get annual AC maintenance visits, so it will run efficiently and be ready for the high demand of the summer’s heat.  If you live in the Nashville area and experience any heating or cooling problems, call on Interstate AC Service at (615) 832-8500.

Common AC Problem: AC Doesn’t Cycle On

Written by analytics@markalon.com on . Posted in Air Conditioning. No Comments on Common AC Problem: AC Doesn’t Cycle On

During the summer, your air conditioner (AC) works harder and longer.  That high demand may cause a problem to rear its ugly head.  In this multi-part post, we’ll take a look at some of the most common AC problems, talk about the possible causes, and provide suggestions for tackling each problem.

AC Doesn’t Cycle On

If your AC does not cycle on, check to make sure it has power, that the circuit breaker has not been tripped, and that the thermostat is on and set to cool mode. If these check out, then here are some possible causes:

  1. System has frozen up: You might see ice on the inside or outside unit. This is typically a sign that there is a refrigerant leak (described above), but it could also be a sign that the ductwork is blocked or a dirty air filter. Turn the system off, turn the thermostat to fan, and wait for the ice to defrost, which may take several hours. Meanwhile, call an AC professional.
  2. Condensation (drip) pan is full: When condensate drips from the evaporator into the drip pan, the excess water should be carried away via pipes to the outside. If these pipes – the condensate lines – get clogged, a water float switch will automatically turn the AC unit off. If your unit is not equipped with a float switch, you will instead see water leaking from the around the drip pan. Dry out the drip pan and clean the condensate line. Refer to our post Clean Condensate Lines to Prevent Mold).

Avoid AC Problems

Summer can be the best time of the year, so don’t let air conditioning problems hinder you from enjoying it.  Be sure to get annual AC maintenance visits, so it will run efficiently and be ready for the high demand of the summer’s heat.  If you live in the Nashville area and experience any heating or cooling problems, call on Interstate AC Service at (615) 832-8500.

Common AC Problem: AC Blows Hot Air

Written by analytics@markalon.com on . Posted in Air Conditioning. No Comments on Common AC Problem: AC Blows Hot Air

During the summer, your air conditioner (AC) works harder and longer.  That high demand may cause a problem to rear its ugly head.  In this multi-part post, we’ll take a look at some of the most common AC problems, talk about the possible causes, and provide suggestions for tackling each problem.

AC is Blowing Hot Air

If your AC is not cooling or is blowing hot air, here are some possible causes and solutions:

  1. Thermostat turned to heat mode: Switch it back to “cool” and you’re good to go.
  1. Dirty evaporator coil caused by a dirty air filter:  Change air filters.  You may also need to have the evaporator coil (inside the indoor part of the AC unit) professionally cleaned.
  1. Condenser coil obstructions: Check the outside AC unit for anything blocking the condenser’s air flow, and clean any debris (such as grass clippings, overgrown bushes, etc.) around the unit.
  1. Low on refrigerant/Freon:  This is usually caused by a refrigerant leak somewhere in the system and looks like ice forming on either the inside or outside unit or both.  For this, you’ll need to contact an AC professional.  See our post Adding Freon to your AC is NOT a DIY Project.

Avoid AC Problems

Summer can be the best time of the year, so don’t let air conditioning problems hinder you from enjoying it.  Be sure to get annual AC maintenance visits, so it will run efficiently and be ready for the high demand of the summer’s heat.  If you live in the Nashville area and experience any heating or cooling problems, call on Interstate AC Service at (615) 832-8500.

Common AC Problem: AC Runs Continuously

Written by analytics@markalon.com on . Posted in Air Conditioning. No Comments on Common AC Problem: AC Runs Continuously

During the summer, your air conditioner (AC) works harder and longer.  That high demand may cause a problem to rear its ugly head.  In this multi-part post, we’ll take a look at some of the most common AC problems, talk about the possible causes, and provide suggestions for tackling each problem.

AC Runs Continuously

Perhaps the AC is cooling but you notice it’s working harder and longer.  You might also notice a sharp increase in your energy bills compared to last year at the same time.  This may be due to a sensor problem, which is causing improper monitoring of the temperature of the evaporator coil.  Typical sensor problems include: the sensor isn’t positioned in the right place, the connections to and from the sensor have failed (due to an electrical short, for example), or the sensor itself has died.  A professional AC technician will be needed to investigate and remedy these situations.

Avoid AC Problems

Summer can be the best time of the year, so don’t let air conditioning problems hinder you from enjoying it.  Be sure to get annual AC maintenance visits, so it will run efficiently and be ready for the high demand of the summer’s heat.  If you live in the Nashville area and experience any heating or cooling problems, call on Interstate AC Service at (615) 832-8500.

Common AC Problem: Unit Shuts Off Repeatedly

Written by analytics@markalon.com on . Posted in Air Conditioning. No Comments on Common AC Problem: Unit Shuts Off Repeatedly

During the summer, your air conditioner (AC) works harder and longer.  That high demand may cause a problem to rear its ugly head.  In this multi-part post, we’ll take a look at some of the most common AC problems, talk about the possible causes, and provide suggestions for tackling each problem.

Unit Shuts Off Repeatedly

If the unit is turning on and off repeatedly, or has difficulty switching on, or you hear a choking and stuttering sound while turning it on, there is short cycling problem.  This can severely damage the compressor, stress the other components, and will consume excess electricity.  Some possible causes are an electrical short somewhere in the system, poor wiring (this is serious and could cause a fire), a damaged or failed part in the system, dirty air filters, or blocked ducts preventing the flow of air.  If you continue to have a short cycling problem after checking your air filter and vents, turn the system off and contact an AC professional.  In some cases – especially if the problem has persisted a while – you may require a new AC unit entirely..

Avoid AC Problems

Summer can be the best time of the year, so don’t let air conditioning problems hinder you from enjoying it.  Be sure to get annual AC maintenance visits, so it will run efficiently and be ready for the high demand of the summer’s heat.  If you live in the Nashville area and experience any heating or cooling problems, call on Interstate AC Service at (615) 832-8500.

Common AC Problem: Noises

Written by analytics@markalon.com on . Posted in Air Conditioning. No Comments on Common AC Problem: Noises

During the summer, your air conditioner (AC) works harder and longer.  That high demand may cause a problem to rear its ugly head.  In this multi-part post, we’ll take a look at some of the most common AC problems, talk about the possible causes, and provide suggestions for tackling each problem.

Noises

While your AC is running, you should hear the hum of the blower, a click when your air conditioner turns on, and the whir of the outside condenser fan.  Other noises – such as rattling, screeching, thumping, clanging, or banging – mean your system is having problems.  Typical causes of noise from the AC unit include: a belt wearing out, loose hardware, a failing motor, refrigerant issues, or blower issues.  But try these things first: make sure the filter is clean, that the air vents in all rooms are unblocked, and that there are no obstructions around or in the outside unit.  If you still hear strange noises, contact a professional AC service technician before the situation worsens and leads to big repair bills and prolonged downtime.

Avoid AC Problems

Summer can be the best time of the year, so don’t let air conditioning problems hinder you from enjoying it.  Be sure to get annual AC maintenance visits, so it will run efficiently and be ready for the high demand of the summer’s heat.  If you live in the Nashville area and experience any heating or cooling problems, call on Interstate AC Service at (615) 832-8500.

Common AC Problem: External Fan Not Working

Written by analytics@markalon.com on . Posted in Air Conditioning. No Comments on Common AC Problem: External Fan Not Working

During the summer, your air conditioner (AC) works harder and longer.  That high demand may cause a problem to rear its ugly head.  In this multi-part post, we’ll take a look at some of the most common AC problems, talk about the possible causes, and provide suggestions for tackling each problem.

External Fan (Compressor) Not Working

Check all around and inside the outdoor unit.  Verify that the fan blades are unimpeded.  It could be that the outdoor unit sustained damage due to falling debris from storms.  Be sure to keep the area around the outdoor unit clear of debris and check it often throughout the summer and fall.  If there are no obstructions and the fan blades are not turning, it could be caused by a lack of power to the system.  Cycle the power by turning the circuit breaker off and back on again, then set the thermostat lower than the current inside temperature and wait 2-5 minutes.  If you do not hear the compressor kick in and the fan blades start to turn, you probably have a faulty motor or compressor, and will need to contact a service professional.

Avoid Summer AC Problems

Summer can be the best time of the year, so don’t let air conditioning problems hinder you from enjoying it.  Be sure to get annual AC maintenance visits, so it will run efficiently and be ready for the high demand of the summer’s heat.  If you live in the Nashville area and experience any heating or cooling problems, call on Interstate AC Service at (615) 832-8500.