Frequently Asked Questions

Is it OK to close supply registers in rooms we are not using so we can save energy?

NO! . . . But read on . . . Closing only a couple of registers in the unused rooms or spaces is OK but don’t close more than a couple because your heating and air conditioning system is designed to have them all open. Restricting air flow through the system will cause the system to overheat and/or over cool.

Isn’t it a good idea to close some of the downstairs registers to force more warm or air conditioned air to go upstairs where it’s cold in the winter and hot in the summer?

NO, it’s not a good idea to close more than a couple of registers for the reasons given in A1. In addition if you close too many registers during air-conditioning season you may cause your air conditioner evaporator coil (cooling coil) to freeze-up and that leads to self destruction.

How often should I change my furnace air filter?

Every month. However, you may not need to do it that often if you have an electronic air cleaner or a deep pleated high capacity filter and no extraordinary amount of dust is being created in your home you can go much longer. You may only need to replace media or service your filter/air cleaner every six to twelve months. Ask your heating and cooling systems service company to give you some advice.

Why is my upstairs too hot? Why is my basement or lower level too cold?

Since warm air is more buoyant than cool air, warm air goes to the highest places it can find in your home. To counteract that situation the heating and cooling systems need to be designed and installed properly. Since many heating and air conditioning systems were not designed or installed properly substantial changes must be made to provide the comfort you expect. The changes may include duct system modifications, adding an additional heating/cooling system, and zoning which includes adding thermostats. We, of course, suggest that you talk to us, Alex Walter or Tim Stephens about the possibilities for furnace/AC repair and replacement in Denver and the surrounding areas.

What can be done to make the basement warmer? It is so cold that my children can’t play down there. The floor is freezing.

If your basement is finished it may not be practical to install the duct system needed to get warm air down to floor level. In that case we would recommend installing a ductless furnace which would shoot a stream of warm air across the floor. The end result is a comfortable condition for children at floor level. These ductless furnaces in Denver are also wonderful at keeping adults feet warm when sitting quietly watching TV or reading etc.

Can you relocate the outside part of my air conditioner?

Yes, we probably can; however, it’s not as simple to do as it looks. We have to remove the refrigerant (Freon) from the system, relocate the 220 volt electrical wiring, relocate the unit (condenser-compressor) and put it all back together again. It is not an inexpensive thing to do. If your air conditioning system is over 10-years old it may make sense to replace and relocate it with a higher efficiency system.

How long do furnaces and air conditioners last?

Furnaces and air conditioners last 15 to 20 years if they are properly installed and maintained. If they were not sized or installed properly their life may be much less. Proper AC and furnace maintenance in Denver, Centennial, and Aurora CO tends to make good systems last longer and perform more efficiently. We find it very difficult and expensive to maintain systems which were not properly designed or installed.

What is the story on humidifiers? I’ve been told they are prone to becoming moldy or just plain unhealthy.

Modern humidifiers, when installed properly, don’t have standing water in them which would contribute to mold formation. Evaporator pad type humidifiers are constantly flushed with water to keep them clean and free of mold or other organisms. When evaporator pad type humidifiers are turned off or not in operation they dry out so there is no water to feed mold. For proper humidity control in Centennial and Denver, steam humidifiers must be installed so that the steam they produce does not condense on any surface, including ducts, which are colder than the dew point temperature.

How low can I set my thermostat in winter?

We suggest you set the thermostat to whatever temperature you are comfortable with. If you want your home to be cooler during the night we suggest lowering the night time temperature to no more than 6°F below the daytime setting. If you will be away from home for more than 2-days you might set the thermostat to 60°F or so. Setting the temperature to less than 60°F will mean that it may take a very long time for the temperature to reach your comfortable daytime setting. Lower temperatures also tend to be hard on all of the contents in your home.

What temperature setting should we us in the summer with air conditioning running?

A good daytime temperature setting is whatever makes you comfortable, i.e. any temperature between 72°F and 80°F. When your home is unoccupied during the summer we suggest not letting the inside of your home become warmer than 84°F if you have air conditioning. If you let the interior become warmer than that it will take a very long time for the air conditioner to bring the temperature back down to a comfortable level. That’s because all of the things in your home will hold the heat. That stored heat in the furniture, walls, ceilings, and contents must be removed in addition to cooling the air before you are comfortable again.

How can I avoid frozen pipes when it’s really cold outside?

There are at least three things you can do. (1) Disconnect your outdoor hoses from all sillcocks to permit water to drain from the frost proof models. (2) Open lavatory, kitchen sink and other cabinet doors which have plumbing pipes inside. The idea is to let warm living space air into and around the areas where water pipes are located. In the basement or crawl space do what you can to keep pipes from being closed up in wall cavities, ceiling cavities or other spaces exposed to outdoor temperatures. (3) When the temperature is extremely cold outside, i.e. 10°F or less you might turn on all of your water faucets to let a small trickle of water run. Moving water in the pipes is less likely to freeze than water which is standing still.

What is annual maintenance? What should be done?

That depends! We need to get our hands on your system to be able to evaluate it because every system is different. Needed furnace maintenance in Denver depends upon the type of system(s) you have, their age, and their condition. We suggest that you hire us to inspect, test and service your system to get it into proper working condition. Having done that we will make recommendations related to ongoing maintenance.

How do I find a good heating and air conditioning contractor? How do we find a good weatherization contractor?

Ask your neighbors and friends. Ask your public utility. Search the Internet for contractors near you. Find contractors and individuals with NATE (North American Technician Excellence) certifications. Go to to find contractors and individuals with BPI (Building Performance Institute) certification. To find a BPI Goldstar Contractor, go to

What are good HVAC equipment brands?

Most of the better known brands are acceptable. The most important aspect of any heating and air conditioning system in Denver is not the equipment brand but rather its proper installation. Installations which are properly designed and installed for easy maintenance will be winners. We work on all brands and pick the brand of equipment which best suits our customer needs and wants.

Why does my new heating and cooling system make more noise than my old system?

If you perform an AC or furnace replacement in Denver, you may notice more noise. Modern heating and air conditioning systems are designed to be efficient. One way manufacturers achieve greater efficiency is to move more air. Move more but only slightly warm air for heating and move much more slightly cool air for air conditioning. When more air is moved through your existing duct system it tends to make a noticeable sound. If there are any holes or cracks in your duct system you may hear whistles. Sound levels may be reduced by insulating ducts and plugging or sealing holes, gaps and cracks.

Why is one room too hot, and another too cold?

Probably because your duct system was poorly designed and/or installed. We may be able to correct the situation by performing an Denver/Aurora-area duct balancing, installing balancing dampers, a zoning system with additional thermostats, or even one or more additional heating/cooling systems. Ask us and we will suggest alternatives.

How do I keep my system safe?

Have Tim Stephens and Alex Walter maintain it.

How do I protect myself from carbon monoxide?

Be sure that enough combustion air is supplied to all of your fossil fuel (natural gas) appliances including furnaces, water heaters, kitchen range, and gas clothes dryer. Don’t permit an automobile or truck to operate in your attached garage. Don’t operate portable propane heaters or cooking appliances in your home. Don’t operate small gasoline engines (generators or pumps, etc) within your home or attached garage. Have us perform a combustion area zone test in your home. Install low level Carbon Monoxide monitors with alarms in the sleeping room areas of your home.

Should I have my ducts cleaned?

Sometimes Yes and sometimes No. If you have an asthma or allergy sufferer in the family the answer is usually “Yes”, you should have your ducts cleaned. New houses where the builder has used your furnace for heat during construction is always a good indication that the ducts should be cleaned. The best way to know what is inside your ducts is to remove one or several of your supply air registers and look inside with a bright flashlight and mirror. Another place to look which is usually very dusty is inside the return air grills which are usually mounted in the wall either near the floor or ceiling. Assuming there is one, we can also remove a register in your basement ceiling and have look inside. When we do this we will be looking inside your main trunk ducts to see if there is a significant accumulation of dust.

What should I do when I want to finish the basement?

STOP! . . . Don’t do anything until you call us. Don’t let any carpenter or basement finishing contractor in the Denver area do anything in your basement until we have discussed basement heating options with you. If you want your basement to be comfortable in the winter a proper heating system for the basement is a must. If you don’t care about winter comfort in the basement it’s OK to go ahead and let the basement finishing contractor or carpenter do their thing without consulting Tim Stephens or Alex Walter.

What is all this talk we hear about duct sealing? Why should we be concerned about sealing the ducts in our home?

All heating and air conditioning ducts leak. It’s just a matter of how much they leak that we consider. If you have ducts in an unconditioned space, i.e. attic or crawl space you will be wasting energy and costing yourself money because some of the heating and air conditioning you are paying for will be wasted to the outdoors. In addition when ducts leak in those unconditioned spaces they may be pulling hot and/or cold dusty or contaminated air from those places. If all of your ducts are within the conditioned space of your home you may not be wasting heating or cooling to outdoors but you are compromising your comfort. Leaky duct systems keep the correct amount of conditioned air from reaching the rooms and spaces where it is needed for comfort.

We can help you by using our duct sealing and duct balancing for Denver homeowners. Be sure to ask us about the alternatives including the Aeroseal process.

What do you recommend for humidification? We find it is so dry here that we think we should have a humidifier installed.

Because your home can be very dry in the winter, with the indoor relative humidity in the single digits, we do recommend installing a humidifier with each heating system for proper humidity control in Centennial, Denver, and Aurora CO. There are two primary types of humidifiers. One is the evaporator panel type which is like a wet sponge from which water evaporates to add needed humidity. The second type is the steam humidifier which is typically suited to larger homes, i.e. over 3,500 square feet in size. Please have us inspect your heating system(s) so we may suggest the best humidifier for your situation. We consider at least a dozen factors when evaluating your home for humidifier installation.

What kind of furnace filter should I be using?

If you have to remove one of your furnace doors to change filters we find that to be an unacceptable situation. It is usually impossible to insert and remove filters within the furnace cabinet. And even when you are able to insert one it probably lets a considerable amount of air bypass or go right around the filter. If you have an older electronic air cleaner it probably does not work any more due to age or lack of ongoing maintenance. We also find that most heating and cooling systems were installed with small filters, too small for the size of the heating and cooling system. In many if not most cases there should be two return air ducts and two filters instead of just one return air duct and one filter.

In any of the foregoing situations a new air filtration system is not only a good idea but also may be a necessity. We can often install a larger or an additional return air duct for Denver-area homeowners. Then we install modern high efficiency air cleaners which may only need annual instead of monthly or quarterly maintenance.

Why is an energy audit a good idea?

An energy audit in Denver, or Aurora CO makes you a smart homeowner. An energy audit reveals the energy robbing aspects of your home and permits you to make wise decisions regarding improvements. Many homeowners think that replacing windows is the first thing which should be done to reduce energy consumption and improve comfort. In reality we have found that there are several things which are more important and should be fixed first, before windows are replaced.

Air sealing of holes, gaps, and cracks in the exterior is usually the number one thing to do. There are holes, gaps and cracks between the ceiling and attic which must be sealed. If your home has a crawl space it must be properly sealed. And after sealing all of the gaps, holes and cracks in your home the amount of insulation in the attic and walls must be brought up to current energy code standards. All of this should be done before even thinking of changing windows. Please talk to us about having an energy audit performed on your home. Home-energy audits in Aurora CO and Denver CO are very reasonably priced and will give you lots of bang for the buck.

Isn’t it OK for me to install a 5-ton air conditioner even though my contractor says I only need a 3-ton air conditioner?

NO! . . .Bigger is NOT Better! Having a larger capacity air conditioner or furnace-heater than is needed will waste energy, cost more to operate, and provide less than optimal comfort. Over-sized equipment will “short cycle”. It will turn on for short period of time and then turn off, turn on for a short period of time and turn off, over and over again. Air conditioners and furnace-heaters are most efficient when they run for longer periods of time. Ideally they would never stop running; however, that is not realistic since outdoor temperatures change so the need for cooling and heating changes with time, date and season.