Q. My house was built 18 years ago and the last HVAC technician, who came in, told me that my system will need to be replaced soon. So I’ve looked into the matter….. and from what I can tell, it’s more expensive to buy a energy-efficient system than the standard systems. Why on earth should I consider spending more for a high-efficiency unit?

A: The difference in energy savings between a 10 SEER air conditioner—the lowest efficiency available—and a 13 SEER is 30 percent. Typically, the installer or the local serving utility can calculate your annual energy savings and you can then make a purchase decision based on that.

You may also want to consider the environmental benefits inherent in energy efficient equipment or the fact that some manufacturers of higher efficiency equipment provide other incentives, such as a more comprehensive warranty, quieter operation, better humidity control, and some utilities provide rebates for the installation of certain higher efficiency equipment.

Don’t quickly overlook all the benefits of energy efficiency system by focusing only on the initial cost—think long term.
Q. Every year around the same time- the first time I turn my system on in the winter- there is a unpleasant odor in my house. The odor makes me and my family nervous. Can you please tell me what is it?

A: Your furnace has been "unemployed" from early April or mid-May until late September, or even early November. Guarenteed you haven’t gone into your furnace, on a weekly basis . . . with a feather duster.

Basically, your furnace has accumulated dust on the heat exchanger or the heat pump's resistance coils. Your nose is detecting the once-a-year odor which is the result of dust meeting high temperatures. Typically, this odor will disappears after two to three uses at the beginning of the winter season.
Q: How does my HVAC (heating, air conditioning and ventilation) system move air throughout my building?

A: Fans draw air in through grilles called returns, force air is moved through ducts and into the conditioned space through supply registers.
Q. What are ducts?

A: Most ducts are constructed of metal and installed by tradesmen called sheet metal workers. However, rigid fiberglass and flexible round ducts are also used, as well as "hollow" constructed spaces within the building. For example, the space between floor joists is sometimes used as the return air path.
Q. How can I get the right duct for my house?

A: Code-making bodies recognize construction standards developed by SMACNA, the leading authority of duct construction and installation. SMACNA contractors should be your preferred source for  HVAC Expertise regarding duct selection.
Q. Should I just go with whatever the builder recommends?

The builder will not pay your future utility bills; you should take an active role in choosing all energy-related decisions. Regarding ducts, each material has characteristics that may favor its use in specialized applications. Sheet metal has a number of advantages – that’s why it has historically been the number one HVAC system choice and remains there today! In fact, sheet metal use in HVAC is larger than all other materials – combined.

Q. What about the environment?

Those taking all elements of the construction industry towards "green" buildings are quite pleased with sheet metal. We’re talking about basic metals like: steel and aluminum which are materials that are easily recycled.

When your HVAC system is upgraded, the duct system may need to be removed and replaced with a newer design. It’s a good bet that the sheet metal duct removed from your house will end up back where much of it is returned to the industry – at a metals' recycler!

It is important to know that sheet metal ducts can be more easily and thoroughly cleaned than other duct material choices if the need should ever arise.
Q. Should I just ignore the ducts?

Ducts that are improperly constructed, sealed, or installed can leak excessive amounts of air and provide poor air distribution which in turn can cause "pipe" noise around the home.

Additionally, ducts can become dirty if put into service before the home’s construction is complete; there’s a lot of dust and dirt around most construction sites.

Furthermore, ducts in older homes can become dirty over time, especially if filters aren’t changed on a regular basis.

Ducts play a key role in determining the energy usage from how much friction the fan "sees" as it moves air throughout the duct system to how well they distribute heating and cooling to keep occupants comfortable.
Q. OK – How do I reduce duct leakage?

If you’re building a new structure, make sure the HVAC system designer is specifying SMACNA’s prescriptive duct sealing standards.

Our companies and workers, who have trained in this industry and gained a vast amount of HVAC expertise, recommend prescriptive sealing of ductwork as one measure that will normally lead to the most cost-effective control of leakage without the need of expensive leakage testing.

Code-making bodies nationwide recognize construction standards developed by SMACNA, the leading authority on duct construction and installation.
Q. How often should we replace the HVAC system filter?

A: There’s no one-size-fits-all answer. The frequency of filter changes will depend on how much you are using your HVAC system. Also take into count severity of the seasons.

In some locations cooling systems might be used more often then others – to keep the heat and humidity under control. If your house is in a hot and humid location, you should pay a lot more attention to your filter, than the area the air conditioning is seldom used. The same logic applies to heating. If the heat is used only on the cold days of winter, then filters would be checked less often.

Start by checking your filters at least once a month. Hold the used filter up to the light and compare it to your clean "spare" filter. When light is obscured by captured dust and dirt particles, the old filter should be changed. Keep a record of your filter replacements for  one year and used that as your yearly guide. It is always a good idea to change filters at the start of the heating and cooling seasons and between.

Q. We have heard that HVAC systems commonly have a problem with mold which makes us nervous as parents of two children who are far apart in age. Both of their schools were closed due to detection of mold and having to clean it out. Ive also heard that these “major mod clean-ups” aren’t very effective! Can this also occur in our home?

A: Mold is a "whole structure" issue and the broad answer to your question is to keep moisture out of the building by controlling and containing it.

Roofs can leak…. window flashings can leak… and pipes that are carrying water can leak. Anywhere you have water or excess moisture; you must control and contain it. An HVAC system’s ducts can become contaminated – but the root cause is invariably uncontrolled moisture, not the ducts. Of course, if moisture enters a building – such as, the schools your children attend – in excessive amounts – and mold does grow – the ductwork can convey mold and excess moisture to other parts of the building.

But the solution isn’t replacing the ductwork or turning off the ventilation system. The answer is identifying how the moisture is getting into your building and correcting the problem. This is a “moisture management” issue.
Q. We’re running tight on money and would like to avoid paying for a service call. Would you tell us how to do that?

Here are some simple things homeowners can check before calling:

1. Check your thermostat—do you have it set for heating or cooling and is the choice appropriate for the season or is it inadvertently in the "off" position?

2. Check the air filter. If it’s very dirty – if it hasn’t been changed in months and it’s clogged with dirt – your system’s working hard to get ANY air through. Replace the filter and see if the system will operates properly.

3. Check if something is blocking the free access of air to your outdoor unit—this applies to air conditioners and heat pumps. Shrubs and bushes can block and restrict airflow to outside units and snow can drift against outdoor heat pump coils.

4. Check your electric fuses and breakers. As you know, your HVAC system uses electric power to do its job. Your load center has fuses or circuit breakers. One or more provides power to the HVAC system. You might have one for the furnace and another for the air conditioner. For a heat pump, one is usually provided for each separate piece of heat pump equipment; one for the air handler and one for the outside unit if you have a split system, for example. If the fuse is blown or the breaker has “flipped” to the “off” position, you can play with the thermostat for an extended amount of time and you won’t accomplish anything.

This is one of the first things our service people check. And you’d be surprised how often a service call consists of not much more than resetting the circuit breaker.

Additionally, your unit might have one or more Disconnect Switches. Perhaps your home has such a switch outside the house. Perhaps a mischievous youth moved the switch from “on” to “off” without you knowing it.

If you reset a circuit breaker or replace a fuse and it immediately trips or blows—call for expert service assistance.

5. HVAC experts recommend regular replacement of dirty filters. Perhaps you have done the required thing and replaced the filter very recently. Very soon after that effort, you might discover the system isn’t doing the job!

If the filter was in the HVAC equipment, go back and check that the system’s fan door is installed properly. Many heaters have a door interlock switch. Your furnace probably will not begin operating until the access door is tightly pushed in.

Modulating Furnaces Set Pace for Comfort
Date: 11/19/2007
Most of us grew up with what seemed like a scary furnace that lived in the basement. It made creepy noises when it started up, and usually overheated the house before it finally shut off. And forget about energy efficiency; many furnaces manufactured before 1992 had AFUE ratings as low as 60 percent.
That has all changed. Over the last decade or so, manufacturers have incorporated numerous innovations into their furnace offerings in order to improve energy efficiency and comfort. Higher AFUEs and two-stage gas valves have ensured better energy efficiency, while variable-speed blowers have increased the level of comfort for occupants.
The latest innovation is the modulating gas furnace. Manufacturers say it maintains constant temperatures while delivering improved comfort, quieter operation, and reduced energy costs. All three of these items are extremely important for homeowners looking to invest in a premium furnace.

UNMATCHED COMFORT
York — A Johnson Controls Company, introduced its Affinity™ modulating furnaces about two years ago. The furnace features a fully modulating gas valve that circulates airflow to closely match the amount of heat needed at any given time. Unlike traditional single- or two-stage furnaces that are staged at fixed input rates and often over- or undershoot the desired temperature setup, resulting in varying temperature swings, modulating furnaces adjust the gas input, inducer speed, and blower airflow.

“The furnace modulates in 1 percent increments from 35 to 100 percent,” said Mickey Smith, York brand manager, Johnson Controls-Unitary Products. “Comfort is drastically improved due to the modulation and is extremely quiet due to the ECM blower motors. The furnace is somewhat intelligent as it continues to narrow the operating band to eventually operate at the same rate heat is leaving the home. It may run longer, but it will run longer at a reduced rate, consuming less energy.”

Several built-in safety mechanisms offer increased customer satisfaction, noted Smith. “For example, if the homeowner is away for a period of time and the product senses there is a blocked flue or some other restriction, the product automatically reduces the level of operation to a safe operating level to continue conditioning the home. Many other technologies will automatically shut off.”

In addition to being energy efficient and quiet, the Affinity modulating gas furnace is also easy to install, maintain, and operate, said Smith. “There are no additional sensors, wires, or controls needed. In fact, it may operate using a traditional single-stage one-heat/one-cool thermostat.”

The sensors and controls automatically compensate for air supply and exhaust variations, wind gusts, and long vent runs. The modulating control employs multiple feedback loops to dynamically adjust the operation of the furnace and optimize the overall temperature control.

Affinity modulating furnaces, as well as modulating furnaces from sister brands Coleman Echelon™ and Luxaire Acclimate™, are available in both a constant-speed blower configuration and a variable-speed blower configuration, and are supported in all positions (upflow, downflow and horizontal). All models within the three modulating series meet the 95 percent-AFUE level required for the Energy Policy Act of 2005 (EPACT), so the units qualify for a $150 tax credit.

New 33-Inch Modulating Gas Furnaces Achieve Up to 98 Percent AFUE

Coming on the heels of its first major product launches in four years, the Unitary Products division of Johnson Controls announced that its 33-inch, variable-speed modulating gas furnaces with electronically commutated motors (ECM) achieve up to 98 percent Annual Fuel Utilization Efficiency (AFUE).

This is the highest AFUE rating in the heating, ventilating and air conditioning industry, according to Andy Armstrong, director of marketing for Unitary Products.  He added that the other modulating ECM models in the Unitary Products line go no lower than 97.5 percent AFUE.

What’s more, Armstrong noted that all of the company’s modulating gas furnaces with permanent split capacitor (PSC) motors have a 97 percent AFUE rating – also an industry first.  In addition, all single-stage furnaces are now rated at 95.5 percent AFUE, eclipsing the previous rating of 95 percent AFUE on condensing furnaces.

“With the introduction of this new line of gas furnaces, Johnson Controls is setting the bar on energy efficiency,” Armstrong said.  “Higher AFUE ratings mean distributors and dealers now have a stronger selling proposition, and homeowners will greatly benefit from lower energy costs during the winter months.”

Johnson Controls recently launched the 33-inch gas furnaces under the York, Coleman and Luxaire brands.  The furnaces appeal to dealers and homeowners searching for efficient heating systems that are easy to install and service in tight spaces while contributing to green, sustainable home design.

The new design also includes the industry’s first fully modulating 80 percent AFUE offering that features integrated controls.  The controls provide comfort to within one degree of the thermostat set point and ensure precise modulation of the gas valve from 50 to 100 percent in 1 percent increments.  Meanwhile, the 97 percent and higher AFUE models modulate from 35 to 100 percent in 1 percent increments.

In redesigning the entire furnace line, Johnson Controls reduced the units’ height by seven inches and incorporated a variety of features, making the furnaces the ideal solution for applications where space is limited, including closets, attics and basements with low ceilings.

Multiple venting options and the multi-position design provide flexibility for all installations and applications, including up flow, down flow, and horizontal left and horizontal right.  In addition, the units’ unique condensate management system eliminates the need for external traps, which means the furnaces do not need to be elevated in horizontal applications.

Their rugged yet stylish cabinets of folded sheet metal are free of sharp edges, ensuring worry-free service.  Moreover, the units’ doors are now interchangeable between the top and bottom, based on the desired venting option, and the tool less ¼-turn latches make door removal even easier.

Operation is quiet – as low as 61 decibels (dB) for models with an 80 percent AFUE rating and 65 dB for models up to 98 percent AFUE.  All 95 percent and higher AFUE furnaces are ENERGY STAR qualified.  And with new gaskets installed around the doors, these furnaces have a reduced air leakage rate of under 1 percent.

Johnson Controls backs every York, Coleman and Luxuries 95 percent and higher AFUE gas furnace with a lifetime warranty on the heat exchanger, while high-end 80 percent AFUE models come with a limited lifetime warranty on the heat exchanger.  Every York, Coleman and Luxuries model includes a 5-year limited warranty on all other components.