HVAC System Buying Guide for the Home Owner

HOMEOWNER'S GUIDE TO BUYING
A High Efficiency Comfort System

Featured in this article are the following topics:
Comfort Systems Buyer's Guide: How to choose the most comfortable system that meets your needs and budget. This covers your Heating System, Duct System, Zoning, Indoor Air Quality, Humidification, and Integrated Home Controls. This guide also includes a Glossary of common terms used in the heating and air conditioning business.
Home Comfort Needs Analysis: Items to consider before buying or upgrading your heating/comfort system.
How to Select a Contractor: Choosing the right company to do the job.

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HOMEOWNER'S GUIDE
TO BUYING A COMFORT SYSTEM
Copyright (c) 1996 by Contracting Business Magazine, Penton Media, Inc. Co., Cleveland, OH. All rights reserved.

If you're replacing or upgrading your home's comfort system, here's a basic guide that can help you choose the most comfortable system to meet your needs and budget.

by Dominick S. Guarinos

A wide range of comfort options for both new and existing homes are well within your reach. Unfortunately, the value of these comfort options is often overlooked when planning, designing or purchasing a home. To a great degree, this stems from a general lack of information available to homeowners, and sometimes builders and HVAC (Heating, Ventilating, and Air Conditioning) contractors, about the benefits of these comfort options.

Here's a look at some of the technologies and products that are currently available, what they can do for you, and, in broad terms, how they work:

HEATING
Copyright (c) 1996 by Contracting Business Magazine, Penton Media, Inc. Co., Cleveland, OH. All rights reserved.

Over the past several years, we've heard a lot about high efficiency furnaces. Actually, that's all manufacturers have been able to offer since January 1, 1992. Why? Because federal laws forbid manufacturing residential furnaces with afues (Annual Fuel Utilization Efficiencies -- a measurement of operating efficiency) below 78%!

This is good news! Why? The cost of heating your home is usually the largest portion of your winter utility bill, so it just makes sense to get the most energy efficiency from your heating system.

Anyone who has ever been around an operating gas furnace realizes that most older furnaces aren't very efficient. The wisp of vapor coming from a chimney or vent on a cold day is a reminder that much of the heat such furnaces produce is blown outdoors.

Most existing furnaces operate at an average efficiency of around 60% -- when they are properly adjusted and maintained. Even steam and hot-water central heating systems seldom achieve efficiencies above 60%, but they must meet the new standards now too.

What makes the new furnaces more efficient? More of the heat that used to be lost up the chimney is now reclaimed and used inside your home. In some cases, as much as 98% of it is now being used! This is why modern furnaces are more complex than their predecessors. They wring almost every bit of heat out of the combustion air before exhausting it outside.

So, why didn't manufacturers do this in the first place? There are three primary reasons:

1. Although the heat we used to exhaust up the chimney may have appeared to be wasted, it supplied the energy for the chimney or vent to draw. Without it, dangerous products of combustion (carbon dioxide, carbon monoxide, aldehydes, and soot) would have accumulated inside your home!

Today, however, either fans or unique combustion methods provide the energy to safely vent top-efficiency furnaces.

2. We were once far less concerned about energy. People treated energy supplies as if they were endless; and low prices didn't encourage conservation. Today we are more aware that natural resources are not endless, and must be used wisely. Also, energy is not getting any cheaper.

3. Buyers of new homes were often more concerned with the initial price of the home than with its long-term operating costs. As a result, many new-home builders didn't offer the choice of high-efficiency options, even when they became available.

New Venting Often Required. With all these changes in furnaces and the type of power used for venting, you may find old chimneys and vents are no longer adequate to remove dangerous products of combustion from your home. The American Gas Association (aga) has furnished guidelines for installers on the new venting requirements. If you're replacing your furnace, ask your installing contractor if your chimney or vent is properly sized for the new equipment.

Furnaces with efficiencies over 90%, because of the small amount of heat wasted, do not use existing chimneys. Rather, they are vented to the outside using PVC pipe. An added advantage is that air for combustion (burning) can also be drawn from outside by these pipes. That way, heated indoor air isn't used in the combustion process -- an added energy savings.

What features should you look for in a high-efficiency furnace? First, look at the efficiency itself. Most manufacturers offer two ranges, those above 78% and those above 90% afue.

Those rated above 90% are called condensing furnaces. They offer the ultimate in energy savings. However, to achieve such high efficiency they require special venting and a drain to remove water condensed from the combustion air (an additional source of heat).

While this may sound like it might not be worth the added small energy savings, remember that such furnaces are usually the manufacturer's top-of-the-line, being the best constructed and offering the most features and longest warranties. Also, the further north you live, the more important this extra efficiency becomes.

Furnaces rated in the 78-80% afue range usually have a lower installed (but higher operating) cost. Some may also be used with existing chimneys -- where they are properly constructed and the connecting piping is short, with few bends. As no water is condensed, no special drains are required either.

Other important factors include:

The amount of sound created by the combustion process and the fans -- indoors as well as outdoors. Ask your installing contractor about this.
The electrical draw also varies by brand and furnace type. Remember: High efficiency should apply to both the gas and electrical use. New ratings from the Air Conditioning Refrigeration Institute (ari) provide comparisons. These ratings are available from the equipment manufacturers.
90+ afue furnaces all have secondary heat exchangers. Important questions to ask are: Can this heat exchanger be clogged by airborne dirt, causing efficiency to drop with age? If so, how is the heat-exchanger accessed for cleaning?
Some top-of-the-line furnaces now offer 2-stage heating and variable-speed fans. Such features offer greater comfort and higher energy efficiency.
Warranties vary, so find out what is offered. Parts and labor are both usually covered by the manufacturer and installing contractor for the first year. Some brands offer warranties up to 5 years, but they usually don't pay for cleaning or checkups -- an important service. So ask your contractor about their maintenance agreements.
Other parts, such as the primary heat exchanger, secondary heat exchanger (on 90+ only), and electronics (where used), often have longer warranties.

YOUR DUCT SYSTEM: AN INSIDE LOOK
Copyright (c) 1996 by Contracting Business Magazine, Penton Media, Inc. Co., Cleveland, OH. All rights reserved.

Your home's duct system is like your body's circulatory system, with the furnace acting as the heart.

Just like your arteries deliver oxygen-enriched blood to every part of your body, and your veins carry away waste and impurities, the supply ducts deliver conditioned air to each room in your home, while the return ducts carry old air back to the furnace to be cleaned and conditioned.

The condition of your ductwork plays a major role in the overall energy efficiency of your home's comfort system. It also affects how comfortable your home is.

For example, leaky ductwork can cause your utility bills to be 20-30% higher than they should be. Leaky ducts also reduce a system's ability to deliver even heating and cooling throughout the home.

Leaks can occur at a number of points in the duct work. Wherever there is a joint, there's potential for a leak. Small leaks in a basement duct system usually are not a problem. However, even small leaks in the supply and return ducts located in an unconditioned space such as an attic, crawlspace, or garage can make a very big difference in energy usage and comfort. There are several good approaches for leak testing a duct system. A professional heating contractor can choose the appropriate testing method based on style of the home, climate conditions, and duct location. Once they leaks are identified, repairs can be made to correct the problem.

Layers of dirt in ductwork can also affect your operating costs and comfort. Most of the dirt accumulates in the return ducts of your system which lead back to your furnace.

Since your air filter is located between the return and your furnace, dirty ducts can quickly clog up a furnace filter causing the furnace and/or air conditioner to work harder. This not only wastes energy, it can also affect your indoor comfort by delivering less cooling or heating to your home.

If your furnace has a standard filter, a large portion of that dust will make it through the filter. This not only coats your equipment with dirt, reducing it's performance and longevity, it also blows the dirt right back into your home.

If you plan to have your ducts cleaned, make sure the company you select is an hvac contractor that specializes in cleaning ductwork, and has the tools and equipment to do the job right. If the ducts are dirty, there's a very good chance the heating and air conditioning equipment also needs to be cleaned.

There are a couple of different duct cleaning methods in use today. Better duct cleaning systems use powerful vacuum machines along with devices like whips, brushes, or compressed air nozzles that are snaked through the ductwork to loosen up caked-on dirt.

A word of caution: If your ducts are made of fiberglass, or have a fiberglass or plastic liner (like in flexible ducts), it's critical that the cleaning equipment used doesn't abrade or tear up the inside of the duct. Improper application of duct cleaning tools on these materials could cause irreversible damage.

Sometimes the ductwork itself can be the cause of restricted air flow, particularly in attics where ducts can be crushed or kinked during the construction process, or afterwards by an unsuspecting electrician or cable TV technician. Flexible ducts are particularly susceptable to being kinked or smashed, since they are generally made of coiled wire, plastic lining, and fiberglass insulation.

If you're having a new home built, make sure your heating contractor designs and sizes the duct system to meet or exceed industry standards. It's very important that the capacity of your ductwork matches the capacity of your furnace and/or air conditioner. Even if the furnace is properly sized for the home, but the ductwork is either too big or too small, the system cannot operate at peak energy efficiency nor can it deliver even comfort throughout the home.

Most duct systems can be fine tuned, or balanced, to deliver the right amount of air to each room or area of the home. Balancing is done by manually adjusting dampers (usually located throughout the duct work) and measuring air flow at each register until the right amount of air is delivered to each room. If your duct system does not have balancing dampers, they can often be added.

Even in an existing home, a poorly designed duct system can be modified to improve system performance. For example, if there is insufficient return air to the furnace (a common problem) a return grille can often be added to produce a better balance of supply and return air. If you're experiencing uneven temperatures, rooms that are too hot or too cold, or lack of control, your duct system could be at fault. If your home exhibits these symptoms, and your thermostat and furnace are operating properly, there's a good chance the problem is in your duct work. A professional HVAC contractor can test your duct system, and determine whether it just needs to be balanced or if more serious repairs are necessary.

ZONING
Copyright (c) 1996 by Contracting Business Magazine, Penton Media, Inc. Co., Cleveland, OH. All rights reserved.

The benefits of zoning include:

Even comfort throughout the home
Control over individual rooms or areas
Up to 30% savings on heating and cooling costs
How does it work? The simplest way to describe zoning is to compare it with how we control lighting in our homes. Each room has its own individual control -- the light switch. This way you don't waste electricity lighting the entire house if you only need light in one or two rooms. In the same way, zone control provides individual comfort control of specific areas within a home. The degree to which a particular area can be controlled depends on the system used. There are basically three ways a home can be zoned:

1. By installing two or more comfort systems, each with totally separate equipment -- for example, two separate furnaces, each with its own thermostat and duct system supplying different areas of the home (See Figure 1).

2. Using a single comfort system with controls for individual zones within the home -- in forced air heating, this is generally accomplished by directing airþow through the ductwork using mechanical dampers controlled by thermostats or sensors placed in each zone (Figure 2). In a hydronic system (hot water heat) a number of zone valves and/or circulator pumps are used to direct hot water to the various zones.

3. A combination of both -- two or more systems within the same home, each sub-zoned into two or more areas using controls.

Figure 1: One way to zone a home is to install two completely separate units, each with its own thermostat and duct system supplying different areas of the home.

Figure 2: This ranch is zoned using a single comfort system with zone controls and mechanical zone dampers which direct air flow only where it is needed.

Artwork courtesy of Trol-A-Temp.

Let's take a more in-depth look at the benefits of zoning:

Comfort: Repeatable, consistent, comfort can be achieved with a good zoning system. Depending on a number of factors including time of year, time of day, wind speeds, outdoor temperatures, infiltration rates, solar gain, etc., different areas of a home will lose heat or gain heat at different rates. In some homes, temperature swings caused by these factors are more acute than in others. A good zone system can correct this problem by supplying heating or cooling to a specific area when it needs it. The more individual control you have of areas within a home, the more consistent the comfort level can be in each zone.
A zoned comfort system can quickly adapt to changing conditions within one area without affecting other areas. For example, it makes sense to zone a two-story home by þoor. Generally the second þoor requires more cooling in the summer and less heat in the winter, while the first þoor often requires less cooling in summer and more heat in winter.

However, demand for heating and cooling can vary from one zone to the other during the course of a day. A well-controlled zoned system can quickly respond to these changes, allowing more consistent temperatures. This usually improves energy efficiency since most of the time, the system isn't conditioning the whole house.

An ideal system would have individual control of temperature, air quality, and humidity in every room. This type of individualized control is technically possible today -- it's already a reality in commercial buildings!

Control: A zoned system allows more control over the indoor environment. A homeowner can decide what areas are to be conditioned and when. The system can also quickly adapt to changes in lifestyle. Often, rooms or areas that were intended for one purpose are converted to other uses -- a home office, for example. Zoned systems can more easily adapt to heating and cooling load changes which can be caused by increased or decreased usage, room additions or enlargements, or a change in occupants.
There is clearly no single best solution to fit all homes. Choosing the right zoning solution for your home depends on the size of the home, the desired degree of zone control, and realistic budgetary considerations.

For example, it wouldn't make sense to have four independent furnaces and air conditioners to condition a 1,200 sq. ft. home. A single system with four mechanically controlled zones can produce the same or better comfort conditions at a much lower first cost (less equipment, materials, and labor); lower energy costs (a single zoned system can be undersized by 10 to 20 % using less energy); and ongoing lower service and repair costs (the single system is less expensive to maintain than four systems).

On the other hand, in a 6,000 or 7,000 sq. ft. home, a single system may not be practical because even if it were used with a mechanical zoning system, it could be harder to accurately control. There would probably be higher losses due to an excessive amount of ductwork or piping, and the system may be difficult to balance and control.

For example, if the blower on a furnace were sized to deliver a volume 2,000 Cubic Feet per Minute (CFM) of conditioned air, and only a single zone capable of using 400 CFM was turned on along with the blower, this could cause a number of problems. Excessive pressure could build up in the duct work, and the system would most likely cycle on and off for very short periods causing poor dehumidification, excessive wear and tear on the equipment, and reduced energy efficiency.

This can be alleviated to some degree by using variable speed equipment. Your hvac contractor is in the best position to determine what system will best suit your particular needs.

In addition to forced air systems, zoning can be used with other comfort systems such as hydronic (hot water or steam) radiant heating, electric baseboard heating, and other types of heating and cooling systems.

Lower Operating Costs: A properly zoned system can save 20 to 30% on energy costs compared to a similar non-zoned system. The zoned system conditions only those areas that require it, therefore it uses less energy by generating less heat or cooling.
In addition, a zoned system often allows the contractor to install smaller equipment without compromising comfort. This can significantly reduce energy consumption by reducing wasted capacity. Also, a zoned system uses fewer pieces of equipment, which means lower maintenance and repair costs.

AIR PURIFICATION AND INDOOR AIR QUALITY
Copyright (c) 1996 by Contracting Business Magazine, Penton Media, Inc. Co., Cleveland, OH. All rights reserved.

Newer homes are more tightly constructed than ever. Although this means less airborne dirt and dust can infiltrate the home from outside, it also means whatever dirt, dust, grease, pollen, and mold spores exist within a home are often recirculated over and over again.

These contaminants can cause unnecessary discomfort, health hazards, and deterioration to property. Dust, pollen, and mold spores can make life miserable for people with respiratory problems, and can harbor harmful bacteria and viruses.

Airborne particles can also cause damage to þoor and wall treatments, drapes, furniture, and home appliances. Home entertainment equipment, computer hardware, and software can easily be damaged from excessive airborne contaminants like dust and pet dander.

A typical furnace filter only removes 10-15% of these contaminants. An air cleaner can remove up to 95% of airborne particles. Several types of air cleaners are available today, each with their advantages and disadvantages.

The three most common types of air cleaners available for residential applications are:

Electronic
Mechanical
Electrostatic

Courtesy of Honeywell, Inc.

Electronic air cleaners (Figure 3), usually have a mesh-type pre-filter which is designed to catch most large particles. Smaller particles then pass through an ionizing section where they receive an electrical charge. These charged particles pass through plates with an opposite electrical charge which attract the particles like a magnet.

The particles remain on these plates until the air cleaner element is washed. Electronic air cleaner elements generally should be washed every two or three months. Most manufacturers provide standard or optional service lights that tell you when maintenance is needed.

Mechanical air cleaners (Figure 4), also known as media-type, generally consist of a pleated material with a surface area many times greater than that of a furnace filter. The material usually is capable of filtering particles in the micron range.

As the material loads up with particles, it becomes more efficient, filtering even smaller particulate matter. Maintenance is performed by replacing the media with a fresh one usually once a year, sometimes more often. Always follow the manufacturer's recommendation.

Electrostatic air cleaners: As dirt, dust and other particles move across a series of mesh elements (usually plastic), the static electricity caused by this friction charges the particles and traps them inside the element. Maintenance, which varies from brand to brand, is performed by removing and washing the filter. The effectiveness of this type of air cleaner varies by brand.

More in-depth information on each of these systems can be obtained through your heating contractor.

Another recently introduced device which is useful particularly in tightly constructed newer homes, is the Heat Recovery Ventilator (Figure 5). This device reduces indoor air pollution in a home by exhausting stale contaminated air and introducing fresh air from outdoors, just as you would by opening a window. Unfortunately, an open window would be unsafe, waste a tremendous amount of energy, and make humidity control next to impossible. The heat recovery ventilator captures up to 80% of the heat from the air being exhausted in winter, and transfers it to incoming fresh air -- and vice-versa in summer. Some models allow the homeowner to control the amount of humidity removed or maintained within the home during the process.

HUMIDIFICATION
Copyright (c) 1996 by Contracting Business Magazine, Penton Media, Inc. Co., Cleveland, OH. All rights reserved.

As winter sets in, a heating system can begin to dry out the air inside a home. As the air becomes dryer, it can become less comfortable - throats, eyes, and noses can become irritated. In prolonged dry conditions, woodwork and furniture can begin to crack and shrink. We all know how irritating it is to be zapped by static electricity. And if you own a computer, a static charge can damage both hardware and software.

Figure 5: A Heat Recovery Ventilator (HRV) reduces indoor air pollution by exhausting stale, contaminated air and introducing fresh air from outdoors. Some HRVs transfer up to 80% of the heat from the exhaust air to the incoming fresh air in winter, and vice-versa in summer.

Artwork courtesy of Bryant/Day and Night.

Even if a home is tightly built, it can lose humidity. Extremely dry cold outside air can quickly drop indoor relative humidity by 10 or 20% (cold winter air does not hold much moisture). Prolonged periods of dryness in a structure can begin to dry and shrink framing, increasing gaps where outside air can infiltrate the walls causing drafts and higher energy consumption.

A properly sized and installed whole-house humidifier can easily correct all of these problems, maintaining a comfortable, healthy humidity level throughout the home. The normal humidity range for human comfort is between 35 and 45% Relative Humidity (RH).

It's important to choose the type of humidifier carefully. For example, studies show that standing water can promote bacteria growth. Better humidifiers are equipped with a drain that removes unused water from within the humidifier either continuously, or when it is turned off. These humidifiers fall into one of two categories:

Power or Direct Humidifier
Bypass Humidifier
Each type has advantages and disadvantages, and each is a better choice for certain applications.

The Power Humidifier has a built-in fan which pulls heated air directly from the hot air (supply) side of the furnace, pushes it across a water panel or media where the warm air picks up humidity and þows back into the supply duct. The humidified air blends with the air exiting the furnace and is distributed throughout the home.

A Bypass Humidifier usually has no fan. It bypasses a portion of the forced air from the supply side of the furnace, forcing it across a water panel or media. The humidified air is then routed to the return side of the furnace, blending with air from the cold air returns. The pre-humidified air is then heated by the furnace and delivered to the conditioned space.

Both types of humidifiers are capable of providing the right amount of humidity. Your contractor/dealer can recommend which one is best suited for your home.

The device that senses and controls the humidity level by turning the humidifier on and off, is called a Humidistat. It's usually mounted either next to the thermostat, or in the main return air duct by the furnace. As the outdoor temperature drops, the humidity level should be slightly decreased to avoid condensation on windows and glass doors. Most humidistats have charts which show the recommended setting based on outdoor temperature.

An option offered by some manufacturers automatically changes the humidistat setting as outdoor temperatures rise and fall. The device uses a temperature sensor located outside the home which tells the humidistat to increase or decrease relative humidity.

INTEGRATED HOME CONTROLS
Copyright (c) 1996 by Contracting Business Magazine, Penton Media, Inc. Co., Cleveland, OH. All rights reserved.

Integrated home control systems are becoming increasingly popular and affordable as the technology has matured considerably over the past decade. In simple terms, integrated means all the components within the system communicate in the same language, and can be controlled through a central system. Comfort systems, lighting, security, appliances, and home entertainment can all be tied together for the ultimate in convenience, efficiency, and control over your environment.

A good integrated system allows the homeowner to control and monitor all vital aspects of the home's systems from both a central system and from within most areas of the home.

These futuristic features are available right now, and can be quite homeowner-friendly. Simple controls using simple commands are taking the fear out of owning a high-tech integrated system. Wider usage is bringing the price down to earth, making it affordable even in mid-range homes.

While a knowledge of furnace features will help you make an informed selection, it is usually more important to choose a good contractor to do the installation first. Although initial installation price may seem to be the most important consideration, far more important questions should be: What is the quality of the equipment and how competent is the installing contractor?

Meanwhile, following is a glossary of some of the terms you'll encounter as you investigate home comfort systemssssss;

FURNACE GLOSSARY
Copyright (c) 1996 by Contracting Business Magazine, Penton Media, Inc. Co., Cleveland, OH. All rights reserved.

AFUE: Stands for Annual Fuel Utilization Efficiency and refers to the ration of annual output of useful energy or heat to the annual energy input to the furnace. The higher the afue, the more efficient the furnace -- higher efficiency translates to more savings on fuel bills.

BALANCING: The process of adjusting the flow of air in duct systems, or water flow in hot-water heating systems. Proper balancing is performed using accurate instrumentation to deliver the right amount of heating or cooling to each area or room of the home.

BTU: Stands for British Thermal Unit and is the quantity of heat required to raise the temperature of 1 lb. of water 1F at 39.2F. BTUH stands for British Thermal Unit Per Hour -- this establishes a time reference to Btu input or output rates.

CENTRAL FORCED-AIR HEATING SYSTEM: A piece of equipment that produces heat in a centralized area, then distributes it throughout the home through a duct system.

CONFIGURATION: This describes the direction in which a furnace outputs heat. A furnace may have an upflow, downflow or crossflow (horizontal) configuration.

DAMPER: A device that is located in ductwork to adjust air flow. There are basically two types of dampers: Manual, and motorized. A manual damper generally consists of a sheet metal (or similar material) flap, shaped to fit the inside of a round or rectangular duct. By rotating a handle located outside of the duct a technician can adjust (see Balancing) air flow to match the needs of a particular area or room. A motorized damper is generally used in a zoned system (see Zoning) to automatically deliver conditioned air to specific rooms or zones.

DUCTWORK: The delivery system through which warm air from the furnace is brought to where it's needed. Ductwork is made of sheetmetal, fiberglass, or flexible plastic, and can be round or rectangular in shape.

EFFICIENCY: The rate at which a furnace maximizes fuel use. This rate is numerically describe as a ratio called afue (see above). As of January, 1991, no furnaces can be manufactured with efficiencies lower than 78% afue. High efficiency furnaces will be rated 85 to 95% afue.

ENERGY RECOVERY VENTILATORS (erv): These devices preheat incoming outside air during the winter and pre-cool incoming air during the summer to reduce the impact of heating and or cooling the indoor air. This means that smaller capacity heating and cooling systems can be used in homes, which results in lower installation costs, lower peak demand for energy, and lower operating costs.

FORCED AIR: This describes a type of heating system that uses a blower motor to move air through the furnace and into the ductwork.

HEAT EXCHANGERS: These are devices that enable furnaces to transfer heat from combustion safely into breathable air. The primary heat exchanger transfers heat from combustion gases to the air blowing through the ductwork. It's vital that non of the combustion gas itself gets into the airstream. The primary heat exchanger handles the hottest gases.

In high efficiency furnaces, secondary heat exchangers recover heat that used to be vented up the chimney with the exhaust gases. By recovering this heat, the furnace becomes more efficient. Part of the heat recovered here causes the water and acid to condense out of the exhaust gas. Because this liquid is corrosive, secondary heat exchangers must be designed to prevent deterioration. Usually this means they are made of stainless steel or some derivative of it.

HEAT RECOVERY VENTILATORS (hrv): These devices bring fresh, ouside air into a home while simultaneously exhausting stale indoor air outside. In the process of doing this, hrvs remove latent heat from the exhaust air and transfers it to the incoming air, pre-heating it. This allows for the reclamation of much of the energy that otherwise would simply be vented outside. The end result: home comfort systems operate more efficiently.

SIZING: Refers to the procedure a heating contractor goes through to determine how large a furnace (measured in Btuh) is needed to heat a house efficiently. Too small a furnace won't deliver enough heating; too large a furnace increases energy costs and can have an adverse effect on comfort. Sizing depends on the square-footage of the home, the amount of ceiling and wall insulation, the window area, use of storm doors, storm windows, and more.

THERM: Another measurement of heat. One therm equals 100,000 Btuh.

ZONING: A system in which living areas are divided into separate spaces and each space's heating/air conditioning is controlled independently. This can be accomplished by using either multiple independent systems, or a single system using electronic controls and motorized dampers (see Damper).

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HOME COMFORT NEEDS ANALYSIS
Copyright (c) 1996 by Contracting Business Magazine, Penton Media, Inc. Co., Cleveland, OH. All rights reserved.

What you should think about before buying or upgrading your home heating/comfort system?

This list of questions is aimed at uncovering information you can use to communicate your comfort needs to your heating contractor.

The questionnaire does not replace a detailed survey of your home by a qualified contractor. It is, however, just as important.

1. Do you or any members of your family have allergies or respiratory difficulties?

2. How many members are there in your household? Are there any elderly people?

3. Is there an area which will be used for exercise?

4. List the types and amounts of cooking done in your kitchen. (Baking, Broiling, Grilling, etc., and those producing steam.)

5. Describe a typical day (routine) in your household, including typical activities of the occupants. Number of baths or showers.

6. Describe an unusual day's activities (things which might be done from time to time which would require extra heating or cooling).

7. Describe the typical usage of the various areas of your home. For instance:

Does someone work at night and sleep during the day?
A formal dining room which is infrequently used.
Home occupied or unoccupied during the daytime hours?
8. Are there special requirements for health reasons such as someone confined to bed, etc.?

9. How often do you entertain?

Winter/Summer?
Typical time of day.
How many people will you usually accommodate?
What types of activities?
In what areas do these activities happen?
Are there times when people would be going in and out frequently?
10. Are there areas which would be closed off to the rest of the house (for zoning and return air purposes)?

11. What do you expect from your indoor comfort system?

12. What temperature would you normally want to maintain in your home?

13. Would there be times when you would want more or less humidity in the home? In any particular area?

14. Would there be times when you would want to have temperatures significantly different from your norm?

In which areas or rooms?
How quickly do you wish the change to occur?
15. To what extent do you wish to be able to control your temperature by room? By area?

16. Do you have any plans to add on to the home? What type of addition and how large?

17. To what extent is energy efficiency important to you?

18. If you could custom tailor the services provided to you by your indoor comfort specialist, what would they be?

19. How responsive, in terms of time, do you want your indoor comfort specialist to be?

20. Are there any considerations not covered?

21. Are any areas or rooms too hot or cold ?

22. Is there a humidity problem? Too much? Too little? When? In what areas?

23. Are there any noise problems caused by the existing heating and cooling system?

24. How long do you plan on living in the home?

25. What do you like about your present system? What do you dislike?

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Perhaps the most important step in replacing or upgrading your home's comfort system is choosing the right company to do the job. A good contractor can help you make the right choices and give you the best value for your money.

Choosing a reliable contractor is, in my viewpoint, more important than the brand of equipment, because no matter how well-made a furnace is or who manufactures it, the comfort, reliability, and energy-efficiency that furnace provides is still in the hands of the company doing the installing.

If you know a good heating contractor, that is an excellent place to start. If you don't, ask your friends or neighbors for recommendations. Remember: What they charge is less important than what kind of a job they do, how honest they are, and how they treat their customers.

Some prefer to get several estimates. That isn't a bad idea, as long as you don't consider lowest price the main reason for selecting a contractor. What should you look for?

Avoid any company offering to give you an estimate without coming out and looking at the job. Such firms may not be interested in a good installation or correcting any existing problems, just in getting in and getting out -- with your money.

A qualified estimator will do a survey and provide a heat-load calculation for your home. Many existing furnaces aren't properly sized, and better contractors provide equipment exactly meeting your home's load requirements. This usually turns out to be less expensive, and a more comfortable installation.

A good company will supply you a written proposal clearly outlining the work to be done and the agreed-on price.

A reliable contractor will usually provide more than one furnace choice, and give you a computer-generated annual operating cost for your home, for each option. Know the costs, quality and savings of the furnace and/or accessories you're buying.

An estimator for a reliable company should ask about heating and cooling problems experienced with your old equipment, then offer understandable solutions.

A good company will usually have a financing plan available.
Most reliable contractors offer extended service agreements which include maintenance inspections.

A well trained, up-to-date contractor won't try to discourage you from purchasing high-efficiency equipment. If they do, get a second opinion.

A good contractor is professional. Their people are prompt; they meet appointments; they are courteous, neat, and well-groomed. This neatness should be reþected in their vehicles and offices.

They should have an office/shop facility, and not be ashamed to have you visit them. Remember:

-- How a company treats you now reþects how they will treat you when there's a problem.

-- The manner in which they take care of themselves, their facilities, and equipment is a reþection of the way they do their work.

-- History of business problems or customer complaints may spell trouble.

Many less-qualified companies don't provide employees proper training. Rather than keep current with the latest technology, some discourage selling new designs.

Your assurance of a satisfactory installation may depend on whether that company stays in business for the first year of warranty. Those who have an office/shop are far more likely to be in business in the future.

Call your local Better Business Bureau or mechanical contractor's association and ask about the company.
You don't have to take the first price that comes along; so if a company is questionable, continue to get quotes until you find one meeting your standards. Demand quality!

What About Price? For us to tell you what a high-efficiency furnace installation should cost would be misleading. Pricing is determined by several factors including: the added costs of correcting venting or ductwork problems; difficulty in installing the furnace in the selected location; code, licensing, or inspection requirements; local labor costs; the quality of job, etc.

Better companies usually charge more, but offer greater value. While one price may look better on paper, the most important consideration is your satisfaction with the end result -- did you get what you paid for?

Reliable companies, those meeting the requirements above, are interested in keeping you as their long-term customer. They want to maintain their fine reputation, so the price offered will usually be reasonable. If you have any questions, ask another company for quote, then choose the best value.