When To Say “Bye-Bye” To Your Old HVAC System

Written on: October 11, 2013 by ICM

According to the U.S. Department of Energy, home heating and cooling typically accounts for slightly more than half of all energy consumed in most residences (54%). This figure can be considerably greater for homes with outdated and inefficient heating and cooling systems. So making informed decisions about the efficiency of your furnace, boiler and air conditioning units can have a huge impact on your utility bill.
The good news is that today’s high-efficiency heating, ventilation, and air conditioning (HVAC) systems are upwards of 60 percent more efficient than technologies from just a decade ago.[i]
This means that your family can slash your bills by hundreds or even thousands of dollars each year while minimizing your environmental footprint.
Replacing an HVAC system can be a big expense, so how do you know when it is the right time to upgrade to a more efficient system? Here are some tell-tale signs that it’s time to update your inefficient HVAC system and start saving on your monthly bills:

  • The Test of Time – A general rule of thumb is that your air conditioner is approaching the end of its serviceable life at around 15-20 years. Heat pumps works year round so they have a slightly shorter life, typically around 15 years. A boiler is generally retired after about 20 years. However, depending on the unit’s operating condition, it may make economic sense to go green sooner, particularly when you take into account the rebates offered by CL&P and UI for upgrading older inefficient units.
  • Climbing Utility Bills – Many homeowners with antiquated HVAC systems will notice a steady upward trend in their utility bills over time as the equipment ages and performs less and less efficiently. The minute you upgrade to the new higher efficiency units, you will be keeping more of those dollars that normally would be paid out to your utility company.
  • Long Run Times – Inefficient systems will take longer to heat and cool your home. So, if you notice your boiler, furnace or air conditioner takes a long time to condition your spaces, it  may be that the equipment’s performance  has peaked and is now slowly degrading as it wears out, and has to work harder to produce the same results.
  • Humidity Problems – That’s right, outdated HVAC units can cause the air to be really dry in the winter and too humid during warmer months.
  • Frequent and More Costly Repairs – If your heating and cooling systems are frequently needing TLC and the cost of those repairs keep getting greater and greater, this may signify that a system is near the end of its serviceable life.
  • Leaking Heat Exchangers – Heat exchangers are the heart and soul of your heating plant, because they transfer heat from the fuel flame to an air or water medium. Over time, these parts wear. On furnaces, this can come in the form of holes, rust and cracks. A breach in the heat exchanger allows exhaust gases to mix with the system’s circulated air and can result in dangerous levels of carbon monoxide and/or exhaust smells inside the house. On boilers, water leaks can cause property damage and in some cases carbon monoxide can be an issue. If your CO detector sounds off, have your equipment checked immediately.As your equipment ages, be mindful that the heat exchanger ages right along with everything else, and again, if you are at the 15-20 year milestone or beyond, it’s a good idea to plan on proactive replacement.
  • Leaking Evaporator Coils – With age, evaporator coils on air conditioners often become corroded, causing refrigerant leakage and inefficiencies in the system’s operation. Two common symptoms that an A/C unit’s evaporator coils are leaking signifying it may be time for a replacement, are 1) if refrigerant levels need to be frequently replenished and 2) if warm air is blowing out when the fan is on.

Even if your furnace, boiler or air conditioning unit is not on its last leg, you may want to consider crunching some numbers to see if a replacement simply makes economic sense. Most homeowners look at the payback period to determine how quickly the savings on their monthly utility will surpass the cost of the upgrade. For instance, if a homeowner pays $4,000 for a high-efficiency furnace and saves $160 per month from the upgrade, they will be paid back on their investment within 2 years, at which time they will actually be cash flow positive.
There is no hard and fast rule for what a good payback period is – it really depends on what you’re comfortable with and many shoot for a payback of five years or less. If the payback period exceeds the expected life of the unit, you may want to hold off on the investment until it really fails.
Be mindful that before any equipment is changed, a sizing blueprint is mandatory. This involves carefully measuring the home to determine the structure’s heat loss and gain requirements, documenting its overall size and shape, size and location of windows & doors, as well as the insulation values of walls, ceilings and floors. Only then can the proper equipment size be determined.  Guesswork and rules of thumb have no place here. Over or undersizing the equipment will unfavorably impact your monthly energy bills. (Click to learn more about “Right Sizing your HVAC System“.)
In addition to updating your HVAC system, there are some quick, easy and inexpensive fixes you can do to minimize the work of your heating and cooling systems.

  •  Programmable Thermostats (and beyond!) – For starters, programmable thermostats allow you to automatically adjust the set point temperature of your home when you are asleep or away. According to the Department of Energy, by setting your thermostat 10 to 15 degrees cooler during the heating months, “homeowners can save up to 15% on their bill. In the summer months, this same strategy – setting your thermostat higher when you’re away – can yield similar results[ii].  Smart phone and web based HVAC controls go the next step and allow you to check your home’s temperature while you are away and change it remotely.  There are even portable thermostat controls like a TV remote.
  •  Zoning Your System – If used properly, system zoning can help you save money on your energy bills. According to the U.S. Department of Energy, it can save up to 30 percent on a typical heating and cooling bill. It is a way to even out your house’s temperature, or to vary the heating and cooling of particular areas based on your usage. Many homes have ducts and/or pipes that are adaptable to system zoning. Zoning a forced air system involves multiple thermostats wired to a control panel, which operate dampers within the existing ductwork. The thermostats constantly read the temperature of their specific zone, then open or close the dampers according to the thermostat’s settings. Zoning baseboard heat involves splitting your existing home mechanically into different zones which can be operated independently.
  •  Duct Sealing – Duct sealing is also a cost-effective way to prevent your HVAC system from working overtime. Ducts distribute the air from your HVAC units, so leaky ducts mean hot and cool air is wasted. According to the EPA, approximately 20% of all hot and cool air is wasted due to leaky ducts.[iii] Sealing cracks and leaks in your duct system can maximize your HVAC systems output. Not only that, sealing ducts ran reduce radon, combustion products and noxious gases in indoor air, as well as minimizing the exchange of pollutants, allergens and dust between rooms.

HVAC systems do not last forever. Keep yours well maintained. Respond quickly to unusual exhaust smells in your living space, soot around heat registers in the house or around the furnace itself, strange noises, or if and when your CO alarm goes off. We can not stress enough the importance of having functioning carbon monoxide and smoke detectors in your home and having your chimney checked annually.
Change out your HVAC system when it makes sense to you and your family, keeping in mind that the huge improvements in efficiency which have been made in these products over the past decade will save you signficant money in the years ahead.
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