Monday, August 31, 2009

What is NATE Certification

What is NATE Certification?

Why is it important?

What does it mean to me?

How do I know if a technician is NATE certified?

The Answer Guide

People want their comfort systems fixed fast, fixed right, and fixed the first time. But how do you pre-judge the quality of service you will receive?

No matter how reputable the company is that you call for service, the quality of your experience is ultimately dependent upon the quality of the technician dispatched to your home. How do you know whether a company employs qualified technicians?

One way is NATE certification.

A Few Facts

NATE is the North American Technician Excellence™ program. Modeled after the ASE certification program in the automotive industry, NATE is the industry standard for technician certification.

NATE is the industry’s national certification program and is supported by the entire industry.

Broad national surveys indicate that consumers overwhelmingly desire certified technicians. In fact, seven out of eight homeowners want their equipment serviced by a nationally certified technician.

NATE certification is far from certain, even for experienced technician. Nationally, passing rates for NATE certification exams are about the same as passing rates for the “bar” to earn a license to practice law.

Why is NATE Certification important?
Heating and air conditioning equipment gets more sophisticated with each passing year. Many of today’s comfort products include computer control boards and high tech sensor systems. Installing and servicing equipment requires more in-depth knowledge and training than ever before. NATE certification was designed to reflect a consensus of the knowledge industry experts determined technicians needed to be able to install and service equipment properly.

Should I allow a technician without NATE Certification to work on my comfort system?
NATE certification is voluntary and many excellent technicians have yet to sit for the NATE exams. In other words, there are good technicians who are not NATE certified. However, the odds of finding a good, qualified, competent technician increases when you insist on NATE certification. NATE certification means the technician is well-grounded in the knowledge he or she needs. NATE certification also reflects a commitment by the technician to the heating and air conditioning industry as a profession. NATE certified technicians are serious about their craft and self-motivated to perform well.

How do I know if a technician is NATE Certified?
For starters, ask for a NATE certified technician when you call for service. Beyond requesting one, identifying a NATE certified technician is often as simple as looking for the NATE patch on the sleeve of their uniform. If you unsure, ask the technician if he or she is NATE certified. NATE also maintains a database of contractors employing NATE certified technicians at

© 2003 Service Roundtable

Sunday, August 30, 2009

A Brief Guide to Mold, Moisture, and Your Home

"A Brief Guide to Mold, Moisture, and Your Home"


petrei dishes with moldMold Basics

  • Why is mold growing in my home?
  • Can mold cause health problems?
  • How do I get rid of mold?

Mold Cleanup

  • Who should do the cleanup?

Mold Cleanup Guidelines

What to Wear When Cleaning Moldy Areas

  • How Do I Know When the Remediation or Cleanup is Finished?

Moisture and Mold Prevention and Control Tips

  • Actions that will help to reduce humidity
  • Actions that will help prevent condensation
  • Testing or sampling for mold

Hidden Mold

  • Cleanup and Biocides

Additional Resources

Mold Basics

  • The key to mold control is moisture control.
  • If mold is a problem in your home, you should clean up the mold promptly and fix the water problem.
  • It is important to dry water-damaged areas and items within 24-48 hours to prevent mold growth.

Why is mold growing in my home?

Molds are part of the natural environment. Outdoors, molds play a part in nature by breaking down dead organic matter such as fallen leaves and dead trees, but indoors, mold growth should be avoided. Molds reproduce by means of tiny spores; the spores are invisible to the naked eye and float through outdoor and indoor air. Mold may begin growing indoors when mold spores land on surfaces that are wet. There are many types of mold, and none of them will grow without water or moisture.

Can mold cause health problems?

Molds are usually not a problem indoors, unless mold spores land on a wet or damp spot and begin growing. Molds have the potential to cause health problems. Molds produce allergens (substances that can cause allergic reactions), irritants, and in some cases, potentially toxic substances (mycotoxins). Inhaling or touching mold or mold spores may cause allergic reactions in sensitive individuals. Allergic responses include hay fever-type symptoms, such as sneezing, runny nose, red eyes, and skin rash (dermatitis). Allergic reactions to mold are common. They can be immediate or delayed. Molds can also cause asthma attacks in people with asthma who are allergic to mold. In addition, mold exposure can irritate the eyes, skin, nose, throat, and lungs of both mold-allergic and non-allergic people. Symptoms other than the allergic and irritant types are not commonly reported as a result of inhaling mold. Research on mold and health effects is ongoing. This brochure provides a brief overview; it does not describe all potential health effects related to mold exposure. For more detailed information consult a health professional. You may also wish to consult your state or local health department.

How do I get rid of mold?

It is impossible to get rid of all mold and mold spores indoors; some mold spores will be found floating through the air and in house dust. The mold spores will not grow if moisture is not present. Indoor mold growth can and should be prevented or controlled by controlling moisture indoors. If there is mold growth in your home, you must clean up the mold and fix the water problem. If you clean up the mold, but don't fix the water problem, then, most likely, the mold problem will come back.

Mold Cleanup

Who should do the cleanup?

Who should do the cleanup depends on a number of factors. One consideration is the size of the mold problem. If the moldy area is less than about 10 square feet (less than roughly a 3 ft. by 3 ft. patch), in most cases, you can handle the job yourself, following the guidelines below. However:

  • If there has been a lot of water damage, and/or mold growth covers more than 10 square feet, consult the U.S. Environmental Protection Agency (EPA) guide: Mold Remediation in Schools and Commercial Buildings. Although focused on schools and commercial buildings, this document is applicable to other building types. It is available free by calling the EPA Indoor Air Quality Information Clearinghouse at (800) 438-4318, or on the Internet at
  • If you choose to hire a contractor (or other professional service provider) to do the cleanup, make sure the contractor has experience cleaning up mold. Check references and ask the contractor to follow the recommendations in EPA's Mold Remediation in Schools and Commercial Buildings, the guidelines of the American Conference of Governmental Industrial Hygenists (ACGIH), or other guidelines from professional or government organizations.
  • If you suspect that the heating/ventilation/air conditioning (HVAC) system may be contaminated with mold (it is part of an identified moisture problem, for instance, or there is mold near the intake to the system), consult EPA's guide Should You Have the Air Ducts in Your Home Cleaned? before taking further action. Do not run the HVAC system if you know or suspect that it is contaminated with mold - it could spread mold throughout the building. Visit, or call (800) 438-4318 for a free copy.
  • If the water and/or mold damage was caused by sewage or other contaminated water, then call in a professional who has experience cleaning and fixing buildings damaged by contaminated water.
  • If you have health concerns, consult a health professional before starting cleanup.

Mold Cleanup Guidelines

Tips and techniques

The tips and techniques presented in this section will help you clean up your mold problem. Professional cleaners or remediators may use methods not covered in this publication. Please note that mold may cause staining and cosmetic damage. It may not be possible to clean an item so that its original appearance is restored.

  • Fix plumbing leaks and other water problems as soon as possible. Dry all items completely.
  • Scrub mold off hard surfaces with detergent and water, and dry completely.
  • Absorbent or porous materials, such as ceiling tiles and carpet, may have to be thrown away if they become moldy. Mold can grow on or fill in the empty spaces and crevices of porous materials, so the mold may be difficult or impossible to remove completely.
  • Avoid exposing yourself or others to mold (see discussions: What to Wear When Cleaning Moldy Areas and Hidden Mold).
  • Do not paint or caulk moldy surfaces. Clean up the mold and dry the surfaces before painting. Paint applied over moldy surfaces is likely to peel.
  • If you are unsure about how to clean an item, or if the item is expensive or of sentimental value, you may wish to consult a specialist. Specialists in furniture repair, restoration, painting, art restoration and conservation, carpet and rug cleaning, water damage, and fire or water restoration are commonly listed in phone books.

    Be sure to ask for and check references. Look for specialists who are affiliated with professional organizations.

What to Wear when Cleaning Moldy Areas

  • Avoid breathing in mold or mold spores. In order to limit your exposure to airborne mold, you may want to wear an N-95 respirator, available at many hardware stores and from companies that advertise on the Internet. (They cost about $12 to $25.) Some N-95 respirators resemble a paper dust mask with a nozzle on the front, others are made primarily of plastic or rubber and have removable cartridges that trap most of the mold spores from entering. In order to be effective, the respirator or mask must fit properly, so carefully follow the instructions supplied with the respirator. Please note that the Occupational Safety and Health Administration (OSHA) requires that respirators fit properly (fit testing) when used in an occupational setting; consult OSHA for more information (800-321-OSHA or ).
  • Wear gloves. Long gloves that extend to the middle of the forearm are recommended. When working with water and a mild detergent, ordinary household rubber gloves may be used. If you are using a disinfectant, a biocide such as chlorine bleach, or a strong cleaning solution, you should select gloves made from natural rubber, neoprene, nitrile, polyurethane, or PVC (see Cleanup and Biocides). Avoid touching mold or moldy items with your bare hands.
  • Wear goggles. Goggles that do not have ventilation holes are recommended. Avoid getting mold or mold spores in your eyes.

How Do I Know When the Remediation or Cleanup is Finished?

You must have completely fixed the water or moisture problem before the cleanup or remediation can be considered finished.

  • You should have completed mold removal. Visible mold and moldy odors should not be present. Please note that mold may cause staining and cosmetic damage
  • You should have revisited the site(s) shortly after cleanup and it should show no signs of water damage or mold growth.
  • People should have been able to occupy or re-occupy the area without health complaints or physical symptoms.
  • Ultimately, this is a judgment call; there is no easy answer. If you have concerns or questions call the EPA Indoor Air Quality Information Clearinghouse at (800) 438-4318.

Moisture & Mold Prevention and Control Tips

  • Moisture control is the key to mold control, so when water leaks or spills occur indoors - ACT QUICKLY. If wet or damp materials or areas are dried 24-48 hours after a leak or spill happens, in most cases mold will not grow.
  • Clean and repair roof gutters regularly.
  • Make sure the ground slopes away from the building foundation, so that water does not enter or collect around the foundation.
  • Keep air conditioning drip pans clean and the drain lines unobstructed and flowing properly.
  • Keep indoor humidity low. If possible, keep indoor humidity below 60 percent (ideally between 30 and 50 percent) relative humidity. Relative humidity can be measured with a moisture or humidity meter, a small, inexpensive ($10-$50) instrument available at many hardware stores.
  • If you see condensation or moisture collecting on windows, walls or pipes ACT QUICKLY to dry the wet surface and reduce the moisture/water source. Condensation can be a sign of high humidity.

Actions that will help to reduce humidity:

  • Vent appliances that produce moisture, such as clothes dryers, stoves, and kerosene heaters to the outside where possible. (Combustion appliances such as stoves and kerosene heaters produce water vapor and will increase the humidity unless vented to the outside.)
  • Use air conditioners and/or de-humidifiers when needed.

Run the bathroom fan or open the window when showering. Use exhaust fans or open windows whenever cooking, running the dishwasher or dishwashing, etc.

Actions that will help prevent condensation:

  • Reduce the humidity (see above).
  • Increase ventilation or air movement by opening doors and/or windows, when practical. Use fans as needed.
  • Cover cold surfaces, such as cold water pipes, with insulation.
  • Increase air temperature.

Testing or Sampling for Mold

Is sampling for mold needed? In most cases, if visible mold growth is present, sampling is unnecessary. Since no EPA or other federal limits have been set for mold or mold spores, sampling cannot be used to check a building's compliance with federal mold standards. Surface sampling may be useful to determine if an area has been adequately cleaned or remediated. Sampling for mold should be conducted by professionals who have specific experience in designing mold sampling protocols, sampling methods, and interpreting results. Sample analysis should follow analytical methods recommended by the American Industrial Hygiene Association (AIHA), the American Conference of Governmental Industrial Hygienists (ACGIH), or other professional organizations.

Hidden Mold

Suspicion of Hidden Mold

You may suspect hidden mold if a building smells moldy, but you cannot see the source, or if you know there has been water damage and residents are reporting health problems. Mold may be hidden in places such as the back side of dry wall, wallpaper, or paneling, the top side of ceiling tiles, the underside of carpets and pads, etc. Other possible locations of hidden mold include areas inside walls around pipes (with leaking or condensing pipes), the surface of walls behind furniture (where condensation forms), inside ductwork, and in roof materials above ceiling tiles (due to roof leaks or insufficient insulation).

Investigating hidden mold problems

Investigating hidden mold problems may be difficult and will require caution when the investigation involves disturbing potential sites of mold growth. For example, removal of wallpaper can lead to a massive release of spores if there is mold growing on the underside of the paper. If you believe that you may have a hidden mold problem, consider hiring an experienced professional.

Cleanup and Biocides

Biocides are substances that can destroy living organisms. The use of a chemical or biocide that kills organisms such as mold (chlorine bleach, for example) is not recommended as a routine practice during mold cleanup. There may be instances, however, when professional judgment may indicate its use (for example, when immune-compromised individuals are present). In most cases, it is not possible or desirable to sterilize an area; a background level of mold spores will remain - these spores will not grow if the moisture problem has been resolved. If you choose to use disinfectants or biocides, always ventilate the area and exhaust the air to the outdoors. Never mix chlorine bleach solution with other cleaning solutions or detergents that contain ammonia because toxic fumes could be produced.

Please note: Dead mold may still cause allergic reactions in some people, so it is not enough to simply kill the mold, it must also be removed.

Additional Resources

For more information on mold related issues including mold cleanup and moisture control/condensation/humidity issues, you can call the EPA Indoor Air Quality Information Clearinghouse at (800) 438-4318.

Back to previous page.

Saturday, August 29, 2009

Dryer Fire Fact Sheet

Dryer Fire Fact Sheet

Statistics and Implications

  • Dryer exhaust fires now surpass creosote (chimney) fires in frequency on a national level. In 1998, the most recent statistics available, the Consumer Product Safety Commission reports that over 15,600 dryer fires occurred killing 20 people, injuring 370 more and causing over $75.4 million in property damage. According to the CPSC, in most of these cases the culprit was lint getting into the machine’s heating element, sparking and fueling a fire. In response to this growing trend, many dryer manufacturers now employ a device that shuts the appliance down when airflow is obstructed. However, these safeguards are subject to wear and have been known to fail. Not surprisingly, some fire departments and insurance companies now require that dryer vents be inspected and cleaned regularly.
  • With gas dryers, there is also concern of carbon monoxide (CO) poisoning. Since lint and flue gases use the same avenue of exit from the house, a blocked vent can cause CO fumes to back up into the house. These fumes are colorless and odorless and they can be fatal. Low-level CO poisoning mimics flu symptoms (without the fever): headache, weakness, nausea, disorientation and deep fatigue. At higher levels, occupants can fall asleep, lapse into a coma and die.

Anatomy of a Dryer Fire

Dryer fires usually start beneath the dryer when the motor overheats. Overheating is caused by a build-up of lint in the duct that increases the drying time and blocks the flow of air, just like cholesterol in your arteries can build up and block the flow of blood to your heart. Naturally, any lint that has collected under the dryer will burn and the draft from the dryer will pull that fire up into the duct. Since the duct is coated or even blocked with lint, many times a house fire results. Other contributing conditions may include failure of the thermostat and limit switches in the dryer, lint inside the dryer, a missing or damaged lint screen, a crushed hose behind the dryer, or a bird’s nest or other debris blocking the vent.

Higher Risk Situations

  • Residential dryer vent lengths may not have an equivalent length greater than 25 feet. Five additional feet for each 90-degree bend must be added to the actual physical length to compute the vent’s equivalent length. This will determine the vent’s actual resistance to the airflow.
  • Homes with larger families or where dryers are used heavily are at greater risk.
  • Flexible plastic duct is no longer code-approved for clothes dryers. It is normally one of the first things burning lint will ignite, having been shown to flame in as little as 12 seconds. Lower cost and high flexibility often make it attractive to unadvised homeowners installing their own machines.
  • Flexible duct made of thin foil is not recommended for clothes dryers. It’s tendency to "kink" and stop airflow makes it dangerous to use.

Warning Signs

  • Dryer is still producing heat, but taking longer and longer to dry clothes, especially towels and jeans.
  • Clothes are damp or hotter than usual at the end of the cycle.
  • Outdoor flapper on vent hood doesn't open when dryer is on.

Additional Benefits to Dryer Vent Cleaning

  • Allows your dryer to operate more efficiently, using less energy and saving you money.
  • Protects your dryer from excess wear and premature death.
  • Helps clothes dry faster—a time savings for busy families.
  • Reduces excess household dust and humidity
  • Helps preserve clothing, as the life of many fabrics is damaged by excessive high heat.

Inspection Frequency

Most vents need cleaning every two to three years. Some dryer vents need attention more often. If it is the first time that a dryer vent has been cleaned, having it re-checked again in a year can help to make a reasonable judgment. Determining factors include:

  • How heavily the dryer is used
  • How long the vent is and the materials used. Shorter vents usually blow better.
  • The age and type of dryer used. Full size dryers blow better than smaller stack dryers or older dryers
  • The design of the vent. Those with a lot of turns and elbows blow worse and build up more lint.

Overheated Clothes Dryers Can Cause Fires

Consumer Product Safety Alert

The U.S. Consumer Product Safety Commission estimates that there are an estimated annual 15,500 fires, 10 deaths, and 310 injuries associated with clothes dryers. Some of these fires may occur when lint builds up in the filter or in the exhaust duct. Under certain conditions, when lint blocks the flow of air, excessive heat build-up may cause a fire in some dryers. To prevent fires:

  • Clean the lint filter regularly and make sure the dryer is operating properly. Clean the filter after each load of clothes. While the dryer is operating, check the outside exhaust to make sure exhaust air is escaping normally, If it is not, look inside both ends of the duct and remove any lint. If there are signs that the dryer is hotter than normal, this may be a sign that the dryer's temperature control thermostat needs servicing.
  • Check the exhaust duct more often if you have a plastic, flexible duct. This type of duct is more apt to trap lint than ducting without ridges.
  • Closely follow manufacturers' instructions for new installations. Most manufacturers that get their clothes dryers approved by Underwriters Laboratories specify the use of metal exhaust duct. If metal duct is not available at the retailer where the dryer was purchased, check other locations, such as hardware or builder supply stores. If you are having the dryer installed, insist upon metal duct unless the installer has verified that the manufacturer permits the use of plastic duct.

U.S. Consumer Product Safety Commission

Tuesday, August 25, 2009

Keeping Minnesota State Fair Cold...

Oh no... Summer's almost over? Not yet, the Minnesota State Fair is typically a hot and busy week. Comfort Matters Heating and Cooling, Inc was able to help keep one of the food stands cold.

Midway Food Company from Winchester, Texas area has a food stand called the Midway Grill and it gets pretty hot working over a grill at the fair. Well only a couple weeks away their air conditioning stopped working on their custom built portable 18,000 pound kitchen. The trailer was out in Montana at a fair when Comfort Matters got the call that they were heading to Minnesota for the fair and needed to get the cooling fixed. Comfort Matters found a Trane rooftop air conditioner in Laramie Wyoming that would work. So within days before the fair the trailer was delivered to Comfort Matters office in Hanover, MN.

"This became a very interesting and custom installation" said Corey Hickmann (owner of Comfort Matters Heating and Cooling, Inc.) We brought in Crystal Welding to help custom build the aluminum frame and ducting so we could mount the new Trane unit on the Roof. Even though it decided to rain most of the day slowing down the work, the new cooling system was up and running the next day and ready for delivery to the fair. The Minnesota State Fair is the largest fair in the country for daily attendance and it is very important to the Midway Grill to have a successful event.

So if you are out at the fair try a burger and fries at the Midway Grill, and if you miss it there it will be heading to Utah, Texas, and a few other stops before the year is over.

Tuesday, August 18, 2009

How to select a contractor.

There are many things to consider when selecting a contractor. This blog is around heating and cooling contractors, but the same principle applies if you are buying a furnace, deck, roof, kitchen, or a basement remodel.

  • Check references: I can not stress this enough. If you are spending $2500 or $10,000 you must check the contractor references. A new furnace or a/c should last 20 years. But even more important is in Minnesota for example you will spend $26,000 over those 20 years on average to heat and cool your home. So ask for testimonials. If the contractor surveys there customers ask to see the surveys. If you want to make the best choice ask to talk to customer they have done work for. Make sure they will call you back on Saturday when it is -20 or 95 degrees outside if your heating or cooling doesn't work.
  • Ask for copy of liability insurance certificate: Check to see what there coverage is. You want at minimum $1 million dollars coverage. Then if you really want to be safe call there insurance company to confirm there premiums are paid in full. To many companies can show a certificate but may not be late on payments. If something happens you the homeowner are responsible. If the contractor is not willing to give you this info "walk away".
  • Confirm they have a current State Bond: In Minnesota for example contractors are required to have a state bond to help protect the homeowner in case the contractor goes out of business.
  • Get Permits: Ask for copy of the local permit at time of installation. Note: some cities do not require permits so you can't in those cases. But call your city hall to confirm that is true.
  • Back ground screened employees: Does the company criminally screen there employees. The people installing your new furnace or A/C have access to your home, make sure they are safe.
  • Does the company work from home: Confirm they actually work from a office. Some contractors may office from home and do great work. But the majority of bad contractors also work from home. Don't base decision on this but it will help.

Don't worry about the brand of furnace or A/C you buy. If it is a Carrier, Goodman, Amana, Trane, Bryant, Chevy, Ford, or BMW it does not matter as much as who installs it. What matters is how well trained the installers are, will they be there for you if it fails, and will it save you money on your energy bills for the next 2 or 20 years. (BTW: no Chevy, Ford, or BMW don't make furnace and A/C)

The upfront cost of the installation will be determined by factors I listed above. Just because someone offers a lower installation you are not saving money. I have learned that lesson over the years. When the cost is lower the odds say something is missing.

Monday, August 17, 2009

Will 2-stage furnace save me money?

Will a 2-stage gas furnace save me money?

Well this is kind of a loaded question. For example I am going to use a 95% efficient gas furnace. The brand does not matter. If you buy a Trane, Bryant, Carrier, Goodman, or Lennox there is not a measurable amount of difference. The bigger difference will be by what company installs it. Majority of furnaces installed are 1-stage. Which means when the house gets cold 100% of the heat comes on. The problem is if it isn't very cold out the furnace may only run for 5 or 10 minutes then shut off. A furnace needs to run at least 10 minutes before you can even get it up to 95% efficient. When if first comes on it will be maybe 50%, then 60%, and keep going up as it runs longer until it reaches peak efficiency. It is like a car, if you drive stop and go traffic your gas mileage is low, but if you go on the highway for 60 miles and don't stop your gas mileage goes up.

So if your furnace turns on and off to often you will not ever get to save money because the furnace doesn't get to peak efficiency. So back to the installing company. If they install a furnace that is to large for your home it will turn on and off to many times during the day cost you money and making your gas company lots of money. So a very common problem is if the installing company selects a furnace that is to large it will run on low stage to often wasting energy. So it is possible to put in a new more efficient furnace but have it not save you any money.

Today we have 1-stage, 2-stage, 3-stage, and modulating furnaces. The advantage of multi stage furnaces is better comfort in the home. If the furnace runs longer it will get the temperature more even in your rooms. Plus the longer the furnace runs and less on/off cycles reliability does go up. So multi stage may help the furnace last longer which will save you money. But you may not be saving what you should be. Depending on model's the first stage (low heat) could be only 70-85% efficient, compared to high heat when it could be 95% efficient. A properly installed 1-stage or multi stage furnace will give you far better long term results. As time goes on gas will keep going up. A well installed furnace could last your 15-20 years. So why over pay each month on your gas bill. Be very careful on selecting your installing contractor because that can save you $1,000's of dollars over the next 15-20 years.

So the moral of the story is "just because your new furnace is 2-STAGE, that does not mean it will save you more money".

Friday, August 7, 2009

How to size a geothermal heating system.

Geothermal heating systems and not much different than standard air source heat pump system. The main difference is geothermal uses the earth to add or remove heat from your home instead of the outside air. With geo the ground will vary from 30-75 degrees typically depending on season. Air source heat pumps need to deal with air temps ranging from -30 to 110 degrees depending if heating or cooling your home.

The big difference with air source heat pump is they can't provide enough heat from the home once outdoor temp gets below 20 degrees. So you need some sort of extra heat whether it be natural gas, oil, LP, or electric heat. Geothermal systems can be designed to heat your home to what ever outdoor temp you want.

Here is the catch to be careful of. If you are converting your current heating system to geothermal the duct work was designed for something else. For example purpose I am going to compare an average gas or oil heat. Now electric heat system won't be much different.


Gas heat systems can provide higher temperature heat in the duct system with less air flow. So when a home is designed for gas the average home needs 1000-1400 CFM. (CFM= cubic feet per minute of air) A home that has a duct system for 1000 CFM with gas heat may now need a 4 ton geothermal heating system. Average design is 400 CFM/ton of geo. So a 4ton geo will need 1600 CFM. The problem is over 50% of home duct systems are undersized in the first place. An educated HVAC company will be able to test your home and see what you can do. Below is a typical solution that way to many heating companies do wrong.

Home needs a 4ton geo which is 1600 CFM but home has duct system only good enough for 1000 CFM. A common answer is to select a 3 ton geo system with gas back up heat. The 3 ton geo will need 1200 CFm. Usually some minor modification can be made to the duct system to handle 1200 CFM. Now when you get to the dead of winter in January when it is -10 and colder for a week straight the geo may not be able to keep up so you will need to use the gas furnace a little. But by going from a 4ton to a 3ton geo you will save about $2,500 just in well drilling. Plus you don't have to tear your home apart making the duct system large enough for a 4ton system. So by going to a 3ton you may save $3500, 4000, maybe 5000. Yes the 3ton may cost an extra $200 per year to heat your home, but it could take you 20 years to equal the $4000 savings.

So in short you maybe able to install a 3ton geo and have a 10 year pay back or a 4ton geo and have a 30 year pay back.

Now these examples above are very general and will vary by area you live or type of home. Point to be aware of bigger definitely is not better when it comes to geo. Now with the 30% federal tax credit geo is cheaper than ever to install and pay back is a lot faster. But don't let a poorly educated installation company steer you the wrong way.