Questions about your
Heating and Cooling (HVAC) Equipment?

Do you have some questions about your heating and cooling (HVAC) equipment? We have assembled some answers to common questions that homeowners and do-it-yourselfers have. If your questions cannot be answered and/or you need a professional to discuss your HVAC equipment with, contact one of the qualified and licensed professional HVAC contractors listed under the Contractor Website Links menu item on the left side column. And tell 'em, "JoeMaintenance sent me."

          Question 1: Should I close the diffusers in an unused room?

Answer 1: Contrary to the many "public service announcements" put out there by utility companies, it is best NOT to close all the diffusers in unused rooms. This can really cause a comfort level problem or an equipment (furnace cycling on the limit) problem when too many diffusers get closed. This restricts the airflow across the heat exchanger and causes the supply air temperature to go up.

The idea that closing diffusers is going to save energy is faulty because the outside walls and ceiling (which are insulated) form the "envelope." Closing off the supply air (heated or cooled) to several unused second floor bedrooms, walk-in closets, and bathrooms results in the remaining room or rooms diffusers having to "carry the load" of the entire second floor. This in turn causes the owner or occupant to call for service when it gets too hot (summer) or too cold (winter) upstairs. 

          Question 2: How often should I change my furnace filter?

Answer 2: If you use a 1" disposable filter you should check it once a month and change as needed. A 1" pleated filter picks up more dirt and should be checked monthly and replaced about every 3 months. A high efficient pleated filter that is 4" to 7" thick can be replaced yearly. If you run your fan constantly as with a variable furnace you may have to change filters twice as often as mentioned because of increased total daily air flow. Don't forget air conditioning season -- it's the same filter to be checked!

          Question 3: I have a humidifer pad. How do I keep it clean?

Answer 3: You can clean your humidifier pad by soaking it in a 50/50 solution of water and vinegar. [Alternate answer] It may be acceptable to use the vinegar soak on old rotating sponge type humidifiers; however, it would not be recommended on the newer evaporative panel humidifiers. The newer evaporative panel humidifiers have a chemical coating on the panel material which helps disperse the water evenly over the panel. The chemical coating should not be removed. The water panel in the newer humidifiers should be replaced once a year or more often in special cases.

          Question 4: How do I know my technician is well-trained?

Answer 4: Ask the contractor how many hours his or her techs spend in training. You can be assured of quality work if you ask for a certified technican, often identified as a NATE-certified technician. NATE is short for North American Technician Excellence.  

 

Question 5: How can I get my second floor cooler in the summer?

 

Answer 5: Install an attic vent fan (not to be confused with a whole house fan) this will automatically run in hot weather and cool down the attic. The cooler attic will help keep the second floor cooler or turn on the furnace blower for constant circulation at the thermostat ( fan on). When the first floor is cool and the a/c shuts off and the blower in the furnace will continue to send air upstairs. This will balance out the temperature from first to second floor.

 

NOTE from Barry A.Sherer, CGA, Owner of Sherer Heating And Air Conditioning, LTD, www.shererheatingandair.com:

 

"Having been an HVAC contractor since the mid seventies, I too, have many stories, some of which can save lives. I am now a Home Performance with ENERGY STAR certified "Shell Specialist" and have learned to look at the home and how it functions as a whole.

I have installed several attic ventilation fans but one summer day I received a call from one of my long time customers with a problem with their carbon monoxide detector going off. Now, I thought these people were nuts for calling me in the middle of the summer because their first finger was pointing at the furnace I just put in earlier in the spring.

 

To make a long story short and not go into all the CO checks I put that basement in, I found that on hot summers days when the attic got hot and the vent fan came on, it ran for hours at a time with no rest. Because the A/C was on, all the doors and windows were naturally closed. This fan, running at 1,100 cfm was actually putting the attic in a negative pressure when it ran. The problem was that there was not enough soffit ventilation to make up this negative air pressure.

 

After it ran long enough the fan started to pull air from other places, which happened to be from the basement which was connected to the attic by way of the gaps around the chimney, the plumbing pipes and the holes around all the numerous wire penetrations into the attic. This fan actually pulled the hole house into a negative pressure and the easiest route for the air to be made up was to back-draft the water heater. This was one case where the homeowner may have saved his own life by not only buying the carbon monoxide detector, but by also calling the professioal to find out how to solve the problem. 

 

Since I have become an ENERGY STAR contractor, I have had the priveledge to be the contractor to have the "attic fans" be included in the worst case senario checks when the home inspections are performed."

 

Question 6: How do I clean my steam boiler?

 

Answer 6: Flush the blowdown valve on your float type low water-cut off once per week during the heating season and then once per month in the summer. For probe type low water cut-off's have a technician remove the insertion assembly and clean the sensing element once per year.

 

Question 7: What are my guidelines for setting a thermostat while on vacation?

 

Answer 7: When you go on vacation be careful not to set the home thermostat at too low of a setting. The heat exchanger of your furnace can be irreparably damaged if the temperature of the air coming into the furnace is too low. Typically furnace manufacturer's recommend a minimum return air temperature between 55 - 60 degrees Fahrenheit. Check with your particular manufacturer to determine how low you can set your thermostat.

 

Question 8: How does the condition of HVAC equipment affect the purchase or sale of a home?

 

Answer 8: (Provided by Alex Walter -- website listed in 'Contractor Websites'.)

 

1) General purpose home inspectors do not typically thoroughly inspect and test HVAC systems. This is due to their lack of knowledge, lack of testing equipment, and/or not getting paid enough to do an adequate job.

 

2) If you really want to know the condition of the house you propose to purchase have licensed contractors inspect it for you, hire a NATE certified HVAC contractor, a licensed electrician, plumber and/or other specialists. Be cautious when realtors suggest specific inspectors as there may be a conflict of interest involved.

 

3) Unless there is a lender requirement to do so THE SELLER SHOULD NEVER be the party to replace or add a furnace and/or air conditioning system due to their condition. The buyer or new owner should be the one who adds to or replaces any significant part of the heating, cooling and/or indoor air quality system(s). Selecting a new or replacement system is not simple and should be selected by the family moving into the house. It’s the buyer’s family who will be living in the house after the seller moves out thus leaving any problems behind. The buyer should develop a relationship with an HVAC contractor as the buyer will need maintenance and service help during future years.

 

4) When owners/sellers sell their homes they very seldom educate the new owner regarding the HVAC systems. The sellers just want to get away leaving any problems and knowledge for the buyers to discover on their own. This is tragic! Buyers should insert language in their offer to purchase which requires the seller to educate the buyer regarding all HVAC, electrical and plumbing systems. This should include turning over all documentation which goes with the HVAC and hot water systems etc. A list of all contractors who have worked on these systems over the last five years should be provided. A certification that the proper building permits have been obtained for the replacement of any of these systems should be provided.

 

5) When basements are finished there should be enough room left around the HVAC and water heater systems to permit easy access for maintenance. For example, some codes require at least 30 inches (more is better) of clear access in front of any furnace etc. Additional space will be needed for the future additions of high efficiency air cleaners, humidifiers, zoning, heat recovery ventilators and/or another water heater etc. Stay away from homes with furnaces/heaters in crawl spaces or roof truss type attics. HVAC equipment in crawl spaces or attics is usually very difficult or impossible to properly maintain.

 

6) After you move in don't wait until you have a problem with your HVAC, hot water or electrical systems to call for help. If you have not already done so develop a relationship with reliable contractors BEFORE you need help. Have those contractors inspect and service your systems soon after you move in. Then they will be familiar with your systems so as to be able to give you outstanding service when needed. The worst way to have to find help is by looking in the yellow pages when you have an emergency.

 

7) Houses and their internal systems are much more complicated than they used to be. Therefore; all of the technicians working on these systems need to be better educated and smarter than ever. Look for experience and NATE certification in HVAC professionals to get competent service and help when you need it. AND expect to pay between $175.00 and $350.00 or more per hour for competent contractor help in your home.

 

Question 9: What is SEER and how should I use that information to select an air conditioner?

 

Seasonal Energy Efficiency Rating (SEER): For residential homes, some countries set minimum requirements for energy efficiency. In the United States, the efficiency of air conditioners is often (but not always) rated by the SEER. The higher the SEER rating, the more energy efficient is the air conditioner. The SEER rating is the BTU of cooling output during its normal annual usage divided by the total electric energy input in watt-hours (W·h) during the same period.

 

Today, it is rare to see systems rated below SEER 9 in the United States, since older units are being replaced with higher efficiency units. The United States now requires that residential systems manufactured in 2006 have a minimum SEER rating of 13 (although window-box systems are exempt from this law, so their SEER is still around 10). Substantial energy savings can be obtained from more efficient systems. For example by upgrading from SEER 9 to SEER 13, the power consumption is reduced by 30% (equal to 1 - 9/13). It is claimed that this can result in an energy savings valued at up to $US 300 per year (depending on the usage rate and the cost of electricity). In many cases, the lifetime energy savings are likely to surpass the higher initial cost of a high-efficiency unit.

 

Bonus Insert

 

A recent newspaper article from Bryant Heating & Cooling talked about the rise in unlicensed HVAC contractors working for people who are looking for the 'cheapest' maintenance on their HVAV systems -- a definite non-no. The article included these key questions to ask when looking for a qualified HVAC contractor:

 

    1. Is the contractor licensed by the state? Many states have websites listing the contractors and the   licenses they hold. In California for example, homeowners can check online at http://www.cslb.ca.gov.

    2. Does the contractor have the right license for the work being performed?

    3. Is the contractor a certified member of a professional organization? To obtain the designation as "NATE (North American Technician Excellence) Certified," for example, contractors must pass a rigorous test.

    4. Did the contractor provide references, and have you solicited proposals to compare not only the cost but the specific work to be performed and the materials used?

    5. Is the contractor fully insured and bonded? This includes workers compensation insurance and general liability insurance for damage to your home or injury to the homeowner or the contractor's employees.