Well, the short answer is, “it depends.”  Ask yourself these questions:

What is included?

If the contract is very cheap, it may be just a ploy to get a technician into your house and try to sell you something you don’t need.  However, if the contract entitles you to a discount on parts or labor, or priority service or emergency/after-hours support, then it might be very well worth it!  If a system is going to break down, it will typically do so at extreme temperatures: the air conditioning will fail on a very hot, humid day, or the heat will fail during a prolonged stretch of frigid weather.  These are times when you can ill afford to be without a working system and when all HVAC companies are inundated with calls.  Without having a company that will put you to the front of the line, you might find the wait with any company you call will be measured in days, not hours!  Additionally, most HVAC companies will charge extra for after-hours support.  You could wind up paying up to twice the labor charges for getting your system serviced on a Saturday versus getting it serviced on Monday.  But in extreme temperatures, you may not be able to wait until Monday!  So, if your service contract entitles you to no additional up-charges for after-hours emergencies, the savings in the labor on just one visit could be worth it.

How old is your unit?

If you have a brand new unit (less than 6 years old), the chances of it breaking down might be less than if you have a unit that is more than 10 years old.  Also, if the unit is still under warranty, then it could be that some portion of parts and/or labor may be covered by the warranty.  But be aware that manufacturers may not honor the warranty if they think the unit has not been properly maintained by the homeowner. Having a service contract where you can prove the unit had regular preventive maintenance might make all the difference.  Certainly, if you have an older unit, or a unit with a history of previous failures, having a service contract might be a smart move!

How diligent are you in doing preventive maintenance?

If you’re following the tips we provide on our HVAC News page, videos, and in our Fall Maintenance eBook, and are diligent about changing filters on time, cleaning the coils, keeping the condensate line clear, and doing other recommended tasks yourself, then you might not gain that much from having a service contract, especially if it only includes these same types of services.  Of course, some preventive maintenance tasks require special equipment, measuring devices, certifications or licensures (such as adding refrigerant to a unit), so there’s no such thing as never needing service.  But if you’re pretty handy and diligent about doing all you can, you certainly will lessen the chances of some things going wrong.

Consider Potential Savings

Annual maintenance is vital to keep your HVAC system in good working condition and at peak efficiency, so you’ll benefit by (a) avoiding big repairs bills, since minor problems could be spotted before they escalate, (b) lowering your utility bills, since your unit will be running more efficiently, and (c) extending the life of your system, so purchasing a new system can be delayed. Like your car, it is cheaper to maintain it in good working order than to deal with large repair bills when it breaks down.

Read  the Fine Print

Always read the contract, so you understand exactly what’s included, and what’s not.  For example, if you purchased a service contract from the gas company thinking it will cover your furnace maintenance, you may find it only covers repairs to the gas lines from the street up to the furnace; the gas company won’t be coming out twice a year for tune-ups and regular preventive maintenance on your HVAC unit.

Consider the Company, Not Just the Price

Remember, the service contract is only as good as the service provider backing it up. Are they honest, trustworthy, and reputable? Are their technicians trained, certified, licensed and insured?  Do they have experience with the type of equipment you have?  Do they treat their customers with respect?  Do they have good online reviews by homeowners (or business owners) and by the Better Business Bureau (BBB)?  Have they been in business a long time?  If you base your service decisions solely on price, you may not be getting a good value for your money.

Heat pumps provide both heating and cooling, so they are very practical for Tennessee’s climate. High-efficiency heat pumps also dehumidify better than standard central air conditioners, resulting in less energy usage and more cooling comfort in summer months. However, the efficiency of most heat pumps as a heat source drops dramatically at low temperatures, generally making them unsuitable for cold climates.

Technology Advances

The new crop of heat pumps offer technology advances that not only make heat pumps perform much better during extreme temperatures, but also double the efficiencies of 10 years ago. Indeed, the market has been heating up for heat pumps growing by double-digits in each of the last 2 years! Here are a few of the advanced features:

• Inverter Technology: varies the flow of refrigerant and adjusts the speed of the compressor according to the desired temperature and the current room temperature. By eliminating the cycling on and off of the compressor, efficiency is increased, and the temperature stays more steady.
• Two-Speed Compressors: save energy, reduce compressor wear, and allow zone control (keeping different rooms at different temperatures).
• Variable-Speed Blowers: allow the fans to keep the air moving, minimizing cold drafts, reducing noise from the blower, while also maximizing electrical savings.
• Scroll Compressor: consists of two spiral-shaped scrolls – one remains stationary, while the other compresses the refrigerant. Compared to the typical piston compressors, scroll compressors have a longer operating life, are quieter, and provide 10-15°F warmer air when in the heating mode.
• Back-up Burners: rather than using electric resistance heaters as a backup heat source during extreme cold weather, some manufacturers now use a combustion fuel source such as propane, natural gas, oil, coal, or wood, thus reducing the use of electricity.
• Refrigerants: the new crop of heat pumps use the more environmentally-friendly and less costly refrigerants, and new refrigerant formulations transfer, hold and deliver heat more effectively. Plus, the copper tubing through which the refrigerant travels has grooves on it to increase surface area, which also boosts efficiency.
• Computer-controlled motors and valves: consume less electricity and provide more precise control of the refrigerant flow.
• Electronic, programmable  thermostats: many of which are now wireless or Internet-capable, allow additional savings and conveniences. Check out our previous blogs on thermostats.

What to Look For

When shopping for a new heat pump system, check the Energy STAR® label and compare the HSPF rating (heating season performance factor) which is an indicator of the efficiency of the compressor and the electric-resistance elements and the SEER rating (seasonal energy efficiency rating), which rates a heat pump’s cooling capacity (see our post What’s Your SEER?).  HSPF should be between 8 and 10 and SEER should be greater than 14. In both cases, the higher the number, the more efficient the unit.

In Tennessee, the humidity can be stifling, especially in the summer! The average morning relative humidity in Nashville during the months of May through October is 85-90%, yet the optimal comfort zone, as published by ASHRAE, is 30-60%. We’re taught to seal up cracks and tighten up our homes so as not to waste energy, but tighter homes can also trap moisture, creating an unhealthy environment. Excessive humidity encourages the growth of mold, mildew, dust mites and bacteria, which in turn worsens allergies and respiratory ailments. In addition, excess moisture can lead to wood rot or warping of floors, beams, cabinets and molding, and cause paint to peel and wallpaper to curl.  If your windows are wet with condensation or you’re having to run your air conditioner so much that you need to sleep with a blanket in the summer, then dehumidification may be necessary.

Portable vs. Central Dehumidifiers

Portable dehumidifiers treat the air in just one room and have a reservoir that needs to be emptied daily in most cases. Central dehumidifiers are connected to your home’s heating and cooling system and treat the whole house. A central dehumidifier pulls air from every room in your home through the return ducts, removes the moisture, and then sends dry air back throughout your home. Unlike a portable dehumidifier, a central dehumidifier is located out-of-sight, is quiet, and hassle-free because you never have to empty a reservoir it is attached directly to your house plumbing.  A central dehumidifier is up to 4-times more energy-efficient than the leading portable dehumidifier (look for ones that are Energy Star rated). Portable systems can remove 5-7 gallons of moisture per day, while a central system can remove 40+ gallons per day.

Features, Functions, and Savings

A central dehumidifier measures the condition of your home’s air to decide when to run and is automatically controlled. The desired humidity level can be set to a fixed percentage for a constant comfortable humidity, regardless of how the outside air increases or decreases in humidity. Although the method of control varies depending on the model and manufacturer, many whole-house dehumidifiers have user-friendly digital controls or remote controls. By using a dedicated central dehumidifier along with air conditioning, you can save energy because you’ll be able to increase your thermostat in the summer by at least 3 degrees and be more comfortable.  Many dehumidifiers also provide ventilation and/or air purification, thus greatly increasing the quality of your indoor air and helping allergy sufferers.

The Downside

• Central dehumidifiers can be expensive, ranging from $400 for a 1200 sq.ft. space, to $16,000 for a 2500 sq.ft. home.
• Installation requires specific tools, electrical wiring and plumbing. It generally is not a do-it-yourself task. A trained HVAC technician would need to install it.
• Because central dehumidifiers are built into the ductwork of your home, when you move, they will need to be left behind.

Moisture can lead to costly renovations or mold remediation, so a central dehumidifier may be a wise choice.  But even the best dehumidifier may not work effectively if too much outside moisture seeps into your home from leaky ductwork, a damp crawlspace or basement, improper drainage around your home, or an improperly-sized HVAC unit. You’ll want to investigate and fix these issues before spending money on a whole-house dehumidifier.

As we enter the summer months, high air-conditioning bills seem just as inevitable as death and taxes.  Something most people don’t think about is that incandescent and halogen bulbs act as miniature space heaters, dumping over 90% of the energy they consume into heat… heating up your already-hot home. This means your air-conditioning has to work harder to keep you cool.  LED lighting uses a fraction of the energy consumed by traditional light sources.  They generate very little heat  (3 BTUs/hr vs. 85 BTUs/hr for incandescent bulbs) and remain cool during operation, thus easing the burden on your air conditioning system during hot weather and reducing your overall energy costs.  For every 60W incandescent (traditional) light bulb, you’re spending about $13.86 more in cooling costs per year (based on Nashville/TVA’s current electricity rate of 10.252 cents per kilowatt-hour) versus an equivalent LED bulb, so it can quickly add up!  Even when you consider the initial cost of LED bulbs (currently about $2.48 for a 60W equivalent bulb, compared to about $1.00 for a traditional 60W bulb), the payback period is just 6 months for a light that stays on 8 hours per day..  The savings come from reduced electricity to produce the light as well as the reduced cooling costs.  And just in case you’re thinking that the heat generated from traditional lighting might be beneficial in the winter to help keep you warm, it’s an extremely inefficient heat source, costing over 5 times as much as the typical gas furnace to generate the equivalent amount of heat.  Compact fluorescent light bulbs (CFLs) were promoted as an energy-saving alternative, but they’re no match for LED lighting, and are falling out of favor.

LED stands for light-emitting diode. The light is generated by a semiconductor, creating an effect known as electroluminescence.

Residential Advantages

• LEDs do not contain mercury or toxic materials. However, CFLs contain mercury, which makes them hazardous to handle and to dispose of.
• LEDs are much more durable than incandescent bulbs because they will not shatter when jarred or hit, and are not sensitive to humidity.  Both CFLs and incandescent lights are fragile.
• LEDs have a longer life than any other lighting source on the market.  This means reduced hassle and inconvenience of replacing burned-out light bulbs. You would need 42 incandescent bulbs (changing the bulb 41 times!) to equal the typical 50,000 hr lifespan of an LED bulb.
• Because LEDs run so much cooler than other bulbs, they are safer.  Lighting a holiday tree or other lighting decorations using incandescent lights presents a fire hazard due to the extreme concentrated heat they produce.  Plus LEDs won’t overload wall sockets by stringing multiple strands together.
• LEDs are available in a range of hues, from remarkably bright white, to warm golden, to cool blue.
• LEDs offer design flexibility, and are available in unique styles and shapes.
• LEDs are an easy retrofit.  LEDs can be run with a dimmer (not true of most CFLs), which allows you to adjust the light level to suit your needs and create mood lighting.

Industrial Lighting Advantages

• For industrial lighting applications such as warehouses, high ceiling environments, parking garages, traffic lights, etc. ─ the conversion to LED lighting would save many thousands of dollars in operating costs due to reduced electricity consumption, reduced need for bulb changes, ability to withstand shock, vibrations, and impact, and reduced demand on cooling. Plus, they are “instant on” (don’t have to warm up before emitting a bright light, quiet (no “hum” typical of high-powered fluorescent lights), and don’t require ballasts.
• LEDs are a “green” solution, due to their vastly reduced energy consumption, reduced waste, and reduced toxic hazards ─ a win-win for health, safety, and the environment.

It’s time to convert to LEDs now!

• Why make your air conditioning work harder than it needs to? LEDs provide significant long-term cost savings and help you keep cool.
• If you are looking for ways to reduce your utility bills, increase the energy efficiency of your home and business with aesthetically pleasing lighting solutions, LEDs are currently an outstanding solution.

Repairing or replacing your heating and cooling system is one of the most critical decisions home owners face. Learn more in this short video or read the paragraph below

While there are no hard-fast rules to answer the repair or replace question, we’ve put together some general guidelines in an earlier post.  But perhaps the more important question is ‘Do You Trust Your HVAC Specialist?’ That’s the REAL issue because most of us don’t have the technical expertise to know whether their recommendations are sound.  Many HVAC companies pay their technicians on commission rather than an hourly rate, which means it’s in their best interest to get you to replace your unit when a repair might be all you need.  Repairing often requires higher-skilled technicians, and they may need to spend more time troubleshooting the problem or retro-fitting a part. You want a company that can advise you reliably whether to repair or replace a unit based on what is in your best interest, not based on what is convenient or what earns them the most money.

If you’re on the fence about whether to repair or replace your system, the best solution is to have a highly trained and qualified technician who will give you an honest assessment, and will spend the time to find the best solution to fit your needs. If you don’t feel this way about your current HVAC technician, then you for sure need a replacement… a replacement of your HVAC service company, that is!

Read our HVAC News page, call us, and let us help you with what may be one of the most critical decisions for your home.

Are some rooms in your home too warm or too cold?  Does one floor of your house get much warmer or cooler than the other?  Do you find that some vents blow lots of air while others – usually those farthest from the HVAC source – hardly blow much air at all?  No matter how you set your thermostat, does it seem there is always one (or more) room(s) of your house that don’t seem to get to the desired temperature? What can be done?

Special fans can help move more of the heated or cooled air already present in the ductwork into the desired room.  Fans on or in the ducts pull this conditioned air into the room, keeping it comfortable longer, so your furnace or air conditioner will run less often, lowering your utility bills.  But do they work?

Register Fans
Register fans also called in-floor booster fans are small fans that sit directly in or on the register(s) in the problem room(s).  A few kinds are pictured here.  They are easy to install and inexpensive usually less than $80 each. Some come in different colors, have their own thermostat, are multi-speed, or can be electronically controlled.  Most users of register fans find them noisy and prone to frequent failures/burnout.  They can also be a bit cumbersome since they have an electrical cord that needs to be plugged in (wires dangling across the room).  Most of these small fans are akin to the fan inside the typical desktop computer, and they are not rated with a high enough airflow (cfm cubic feet per minute) to really make a difference.  Some believe register fans further restrict airflow because the vent is now blocked by fans.  However, a few folks have found this simple solution helps.  At least it’s not too expensive to find out.

Mid-Duct Fan
A good alternative is installing a mid-duct fan also called an inline duct fan.  This is a large, heavy-duty cylindrical fan, taking up the entire width of the ductwork, e.g., they “replace” a section of ductwork. They are placed mid-way between the HVAC source and your problem room(s).   Your HVAC ducting must be accessible and exposed to install and work on it.  They require an electrical outlet or they can be hardwired, and require a relay back to the furnace.  So, you’ll need an electrician or HVAC professional for installation.  Inline duct fans are quieter than register booster fans, and cost $30-$150 each, depending on the size (note: you need to know the size and shape of your existing ductwork so you can pick the right-sized unit!), cfm rating, and features, plus a couple hundred dollars for the electrician.

Uneven Heating & Cooling
The solutions described above may fix the symptom of uneven heating and cooling, but it is always best to address the root cause of the problem.  Here are some of the typical things that may contribute to airflow problems:

• clogged air filters,
• air vents or dampers which are blocked by furniture or not opened fully,
• return air registers that are blocked, cracks/leaks in windows and doors,
• a dirty blower wheel and/or coil,
• leaks in the ducts themselves due to peeling duct tape or holes made by plumbing or rodents.

If none of the above things is the source of the problem, you might need to address the problem in another fashion.

Often the biggest challenge is the return air – getting the stale air from the second or third floor back down to the furnace to be heated or cooled and redistributed.  In these cases, the best solution is adding returns or installing a thermostatically controlled zone system.

Having your air duct system professionally balanced might solve the problem and will improve comfort and efficiency.  But if your problem is due to poorly insulated rooms, or undersized ductwork, then no amount of balancing will fix the problem.

The bottom line is that the lack of proper airflow drastically reduces the efficiency of your heating and air conditioning system. Poor airflow decreases system performance, raises utility bills, and reduces equipment life.  It is best to find the root cause of the problem and address it.

Tony Anderson, Partner, discusses the new federal goverment regulations for home HVAC systems.

Effective January 1, 2015 all manufacturers of HVAC equipment can no longer manufacture 13 SEER equipment meaning that you can only buy a complete system with a 14 SEER or better rating.  Commercial HVAC systems are not subject to this regulation.

The repair on any piece of equipment is a personal decision. For example if you are going to stay in your home for the next five years and your eight-year-old 13 SEER HVAC, which uses the phased-out R22 refrigerant, needed a new blower motor, you may want to do that repair.  If you’re only going to be there a year or two, for sure you’ll want to repair it, rather than replace it.  But if you are going to be there for the long haul (10-15 years), you may consider replacing it with a new 14 SEER system that uses the new R410 refrigerant. You’ll get many better features: these newer systems are quieter, they have better blower motors, and the the whole works (compressor, bearings, etc.) are built better with higher efficiencies.

People ask why are we doing this?  It’s just like your car. Every time you look at the gas mileage ratings on cars, it continues to get better and better.  That didn’t naturally happen; it’s mandated by the government.  Same thing in our industry. Heating and air conditioning equipment would have remained at an 8 SEER rating if something better hadn’t been mandated.  Just during my career, the industry has gone from an 8 SEER to 10, 12, 13 and now we are at 14 as the minimum.  Check the yellow tags that come on your equipment to learn what the SEER rating is. These new regulations are good for the consumer because they mean lower utility bills, good for our industry because it forces continual innovation, and they are good for our environment because they consume less energy and deplete the ozone less while providing the same or better comfort level.

Something is not working quite right.  All you know is that it’s cold and your heat does not seem to be working as it should.    Listed below are some common issues, their common causes, and tips on how you may be able to fix the problem yourself, before contacting a service technician for repair.  This can save you time and money.

1.   Filter-related Issues

• Dirty filters are the most common cause of heating (and cooling!) problems because they restrict airflow.  When the filter is clogged and the system can’t “breathe,” the heat exchanger will overheat and shut off too quickly, and your house won’t warm up. It also causes the blower to run hard and for long periods of time, with little heat coming out, and could shorten its lifespan.  Dirty filters also cause soot buildup in the system, reduces your system’s efficiency (thus costing you more money to operate), and shortens its life.  This is an easy solution: replace all filters. Be sure to check for the correct size (they are sold by size, not manufacturer).  Get the highest-rated ones you can afford to get the best indoor air quality and performance.  Important tip:  When you replace the filters, make sure the arrows on the filter are pointing towards the furnace (away from you).  Never try to skimp by vacuuming and re-using filters.
• Listen for a whistling sound.  This is a sign that the system is not getting enough air, due to a clogged filter or obstructed airflow.  If you’ve already changed the filters and still hear the whistle, then there may be an obstruction elsewhere in the system. Check to make sure all the registers are open and unblocked.

2.   Thermostat-related Issues  

• If the display on your thermostat is blank, it could be there is no power to the thermostat.  A tripped circuit breaker or fuse could be the problem, possibly caused by a power outage, power surge, lightning strike, or storm. Reset the tripped circuit breaker or replace the fuse. Make sure all the wires going to the thermostat are connected and not loose.  Useful tip: If you’ve lost your owner’s manual for your thermostat, most major-brand manuals can be found on the web-just go to the manufacturer’s web site.
• Check that the thermostat is in heat mode. If it’s a programmable thermostat, switch it to manual control and set it for 5 degrees above the room temperature, and wait to see if the heat cycles on.   For programmable thermostats, check that it is set to the correct day and time (am or pm).
• If your thermostat is battery-powered, or relies on battery for backup power in case of a power outage, it could be that the battery needs replacing.  If you have a programmable thermostat, and had a recent power outage, it could be that without a functioning battery backup, all of your settings have been wiped out by the power outage and the thermostat reverted to its default program.
• If your thermostat has a switch to control the furnace fan, switch the fan “On” (as opposed to “Auto” or “Off”).  If you do not hear the fan coming on, go to one of the supply registers and see if you can feel any air coming out. If the fan is not running, there may be no power to the furnace.  If the fan runs, but the air coming out is cold, you have a problem with the furnace (or heat pump) itself.

3.   Electrical-related Issues

• Check to see if the circuit breaker or fuse controlling the heating system is tripped or blown.  If a breaker has been tripped it will be in a position that is between ON and OFF. Reset the breaker by turning it all the way OFF, then back ON. If your home has fuses, check to see if the fuse for the furnace is blown. If so, replace it with the same size and type of fuse. Do not increase the size of the fuse. Important Tip:  If a breaker keeps tripping or a fuse keeps blowing, contact a qualified service technician to inspect your system to determine why you are having problems.
• Check to see if the switch located near the heating unit is switched on.  This often looks similar to a light switch and easy to mistakenly turn off.  (In one house, the switch was mounted upside down, so the unit was actually “on” when the switch was in the “down” position!).  Useful tip: Most thermostats get their power from the same electrical circuit that feeds the HVAC system.  So, if your thermostat is not responding, turning on the switch by the HVAC may be the solution!

4.    Furnace-related Issues

• Check to see if the pilot lot has gone out (if your furnace has non-electric ignition).  The solution is to relight the pilot light.  If you are unsure how to this, contact your gas service provider.  If the pilot will not light or stay lit, call a service technician.
• Most furnaces today have electronic ignition switches rather than a pilot light.  If that gets stuck, try switching the furnace off, wait a minute, then switch it back on. If your furnace has a reset switch, press it. After another minute, you should hear the furnace fire up.
• Make sure the gas is turned on.  Trace the gas line back from the furnace to the meter, and if there is a handle that’s perpendicular to the gas pipe, turn it so it’s parallel. There should be no obstructions or kinks in the gas line. Also, if you have other gas appliances and they are all working, then you know the gas line is on and not obstructed.
• Some furnaces have emergency cut-off switches that are activated when a door or service panel is removed. If the furnace door is not closed properly (such as after a filter cleaning, or accidentally bumped open), the cut-off switch will prevent the furnace from coming on.  Check to make sure all access doors are properly closed and secured.
• Make sure the exhaust line or flue is clear.  I’m not talking about the chimney flue in your fireplace, but the part of your furnace that exhausts to the outside, usually through a metal duct.  Sometimes birds, drawn by the warmth, build nests in it.  To clean it, you’ll need to turn off the furnace first.
• High-efficiency furnaces can drain off several gallons of water a day during the heating season. If the drain lines become restricted by sediment or mold growth, the furnace will shut down. If the drain line is in unconditioned space, and the water in the line freezes, that, too, will cause the system to shut down.  Check the drain hose, and if it looks dirty, remove it and clean it with a mixture of 25% bleach + 75% water, and after flushing it for several minutes, replace the hose.

5.   Heat Pump-related Issues 

• Check to see if the outdoor unit is covered in ice. It is normal for the coils to frost-over, especially if there is lots of moisture in the air (mist, rain, or sleet).  Your heat pump has a defrost cycle that normally melts this frost.  However, if the ice on the coils is extremely thick, never seems to melt, and only seems to get worse with time, then there could be a problem with the defrost cycle.  Try switching the system to “Emergency Heat” at the thermostat. Wait until the sun melts the ice off, then try turning the system back to “Heat.”  If you do not hear the heat come on, or if you hear loud noises, turn the system back to “Emergency Heat” (thereby shutting off the outdoor unit) and call for service.
• When outdoor temperatures stay below about 35 degrees, it is normal for the backup or auxiliary heat light (usually a blue or green light) to come on. The colder the temperatures, the longer this light will stay on. But if the light comes on and stays on, even when outdoor temperatures rise above 35-40 degrees, then there is a problem with your outdoor unit and you’ll need to call for service.
• Clean away leaves and debris around the outside unit that could be restricting the airflow.  Be sure the outside unit is not covered if you are trying to use it!

Never fear.  If none of these fixes your problem, we’re always here to help!

Jeff Owens, Project Manager, describes the major project at Brentwood Middle School that installed a green, ductless, HVAC system expected to save 25%-30% of the energy previously required to heat and cool a large school building.

Objectives

Brentwood Middle School opened in August 1972.  It’s a large school with 1,250 students in grades 6 through 8. In 2014, it was named by thebestschools.org as one of the top 30 schools in theO USA.  Learning can be hampered by environments where students are distracted by noise, or in temperatures that are too hot or too cold. In 2013, it was decided that the 41-year-old school should replace its antiquated HVAC system.  They chose a system that would need no ducts for conditioned hot and cool air, would keep classrooms quiet, would let teachers control their individual classroom’s temperature, and would use no floor space for equipment.  The project required removing all the ceiling tiles, all lighting, all the old ductwork, all floor-mounted air handlers, and all roof-mounted equipment.  The work was done during two summer breaks so there was no need to close any classrooms.

Mitsubishi VRF

The system uses  a Mitsubishi VRF (Variable Refrigerant Flow) system. In each of the classrooms we have a ceiling cassette that takes care of this particular room and it’s thermostatically controlled by a white thermostat on the wall. The teacher can control the temperature in each room. Before there was one central thermostat controlling all the rooms.

Ductless

This is called a ductless system and you have no ductwork above the ceiling and you have four directional blowers with air flowing in four different directions in the classroom. There are approximately 74 units throughout the building.  Another good feature for these Mitsubishis is that they’re quiet – only 30-35 decibels. You can’t even hear the thing running in the classroom. It is very quiet unlike a conventional system. Each cassette is connected to a condensing unit on the roof. There are eight condensing units on the roof and each feeds 15-20 air handlers. There is a flow of refrigerant and as the system requires heating or cooling it will flow the refrigerant needed to heat or cool a particular room.  This is a two-ton capacity unit so it can use as much as 24,000 BTUs of refrigerant.

Fresh Air

Of course there has to be a way to bring fresh outside air into each classroom and that does require ducts and vents.  Reznor make-up units on the roof filter the air, and blowers pump the air to the vents. There are no return air ducts. The fresh air pumped in by the make-up units result in the rooms having a positive air pressure, which then exits through leaks around windows and doors.  There are five makeup air units on the roof that condition the outside air. 100% outside air goes in and is heated or cooled as required and then is directed into each classroom.

Energy Savings

As the sun comes up in the morning, one side of the building requires cooling while the other side does not. An energy management system determines which of the eight condensing units to run.  This saves energy. The energy used is being measured by the energy management system and is expected to be 25 to 30% less than the old system.  Data from the old system has been retained and in a year we should be able to report exact figures.

On a cold morning, just the thought of having your feet hit a cold floor makes you want to stay in bed! With radiant floor heat, even your dog will want to curl up on the bare floor rather than in your bed.  Radiant heat has benefits when compared with traditional convection heat. But what is it and how does it work?

Radiant heat elements in the floor, wall or ceiling warm the people and objects in the room rather than directly heating the air. You cannot see radiant heat energy but you can certainly feel it, and it just makes you feel more comfortable and cozy.  It works like sunshine.  When you’re outside on a sunny day, you may feel comfortable in short sleeves even if the air temperature is only 60 degrees. This is because of the radiant warmth from the sun.  Radiant heat lets you feel warm at a lower air temperature than conventional forced-air heat.  Plus, because there is no blower as with forced-air heat, there are no drafts.

Energy Efficient

It is estimated that radiant heat is not only about 30% more efficient than conventional forced-air systems, but provides a more even and continuous level of warmth.  Here’s why:

• With radiant heating, the heating elements are near you in the floor or walls.  No ductwork is needed as part of the delivery system, and ducts are where some heat is lost.
• Since radiant heating systems do not use blowers or fans, your environment stays quieter.
• With radiant systems, heat stays near the floor where you are, and is not collecting near the ceiling.
• Radiant systems easily provide room-by-room temperature control, or multiple separate zones, allowing more heat where you want it most.

Other Benefits

Besides saving energy, here are some other benefits of radiant heat:

• Health benefits: European studies indicate that dust mite populations are reduced as much as 90% in radiant heated homes.
• No humidification needed: Unlike hot air systems, radiant heat will not dry out your breathing passages.  Humidification is unnecessary with radiant heat because it does not alter the air moisture content.
• Environmentally friendly: Radiant systems can run off of a variety of energy sources (gas, oil, wood, etc.), and can easily be interfaced to solar, geothermal, and other renewable energy sources. [For more information on environmentally-friendly systems, check out our LEED story.]
• Flexibility: Radiant floor heating systems can be installed under any type of flooring, including wood, tile, laminate, concrete and carpet. Beautiful wood, marble or tile floors are even more enjoyable because they are now warm, and don’t need to be covered up with rugs to shield bare feet from a cold floor.
• New construction or remodel:  Radiant heating can be customized for rooms of any shape or size, and can convert cold, damp areas into warm living space.  Add radiant floor heat in large lower-level rooms or basements that are almost uninhabitable during winter months, or a garage space being converted into living space. It works really well in a concrete slab, too.

Many Types

There are many types of radiant heating systems.

• Under the floor or in the walls:  These are called low-temperature systems.  Since their heating surface is much larger, a much lower temperature is required to achieve the same level of heat transfer.
• Radiant heating mats: These are ideal for spot heating, like shower floors or benches, and are safe for wet location installations.
• Radiant heating room panels:  These can be hung on the wall (like artwork) and typically are glass or mirrored, and come in a variety of colors and sizes.
• Overhead panels:  These have a lot higher surface temperatures, and can be found in production and warehousing facilities or sports arenas.  They boast the quickest response time of any heating technology.
• Radiant heat can be used outdoors as well.  In cold climates, some folks have heated driveways or roofs so they don’t need to shovel snow or worry about the snow pack causing the roof to collapse.

There are two basic ways to supply radiant heat in floors or walls: hot water or electricity.  Electric radiant, which uses zig-zag loops of resistance wire, is ­generally retrofitted to a single room, such as a bathroom, kitchen, or added room, such as a converted garage. It can be used for spot installations and operate along with traditional forced-air heating systems used in the rest of the house. Hot-water “hydronic” systems circulate water from a boiler or water heater through loops of 1/2-inch flexible plastic tubing.  Hydronic systems are better suited for whole-house (rather than spot) installations.

What About Air-Conditioning?

Keep in mind, no matter what radiant heating system you use, you’ll still need a separate air-conditioning system for cooling.  Radiant cooling cannot be used in Tennessee because our high humidity would cause excessive condensation (not a problem for heating systems).  That means that although radiant heat does not use ductwork, registers or vents for heat delivery, you’ll likely still need these for a cooling system.

But with radiant heat, you can say goodbye to cold floors in winter! Radiant heating can be a comfortable, efficient, and reliable heating choice.