A split-system air conditioner splits the hot side from the cold side of the system, like this:
The cold side, consisting of the expansion valve and the cold coil, is generally placed into a furnace or some other air handler. The air handler blows air through the coil and routes the air throughout the building using a series of ducts. The hot side is known as the condensing unit and is located outside the building.
The unit consists of a long, spiral coil shaped like a cylinder. Inside the coil is a fan, to blow air through the coil, along with a weather-resistant compressor and some control logic. This approach has evolved over the years because it is low-cost and also because it normally results in reduced noise inside the house (at the expense of increased noise outside the house). Besides the fact that the hot and cold sides are split apart and the capacity is higher (making the coils and compressor larger), there is no difference between a split-system and a window air conditioner.
Boilers – Hot Water & Steam Heat
There are several efficiency factors to identify in order to evaluate the cost benefits of efficiency upgrades. These efficiency factors are important because high Appliance efficiency – the annual fuel utilization efficiency (AFUE) for various manufactured appliances – does not always generate the highest Return on Investment. First, Thermal efficiency is the output of an appliance (expressed in Btu) divided by the input (expressed in Btu). Example: If a furnace with an output of 80,000 Btu/hr requires an input of 100,000 Btu/hr, the furnace has a thermal efficiency of 80%. Secondly, Seasonal efficiency is how efficient the appliance uses energy over an entire heating or cooling season. This efficiency is important because it determines how much the building owner will pay for fuel over the course of a heating or cooling season. Finally, System efficiency is how efficiently the components of a heating or air conditioning system use energy. Multiple boiler designs, multiple chiller designs, piping changes, the use of efficient pumps, efficient fan motors and microprocessor controls are a few things that can affect efficiency.
For consideration:
A 5 million Btu/hr input boiler firing at 100% capacity, 24 hours per day for 293 winter days will utilize twice the fuel as four 1.250 million boilers firing for the same period. Multiple boilers will all fire at 100% capacity until the indoor building temperature is satisfied. After this is achieved only one (1.250 million) boiler is needed to maintain the building temperature. As the indoor building temperature drops more boilers are fired. An inexpensive boiler management controller operates the multiple boilers. This results in significant energy savings for the building owner.
By improving the thermal efficiency of appliances and designing improvements for existing heating and cooling systems, we are able to improve seasonal efficiency.
When evaluating a property we focus on the system, trying to maximize an economically achievable efficiency. Each individual efficiency factor has an important role in system efficiency. The starting point to Boiler System efficiency is an Energy Survey. An energy survey will establish at what point your building is …a starting point
Indirect Fired Water Heaters
ATI designs pump mounted indirect fired volume water heaters with extended life expectancies when properly maintained. Components may wear out, however, repair of these components costs substantially less than a new tank type water heater. Tank-type water heaters are “disposable” pieces of equipment that are frequently replaced.
Indirect fired volume water heaters are designed to operate scale-free, even when used in hard water areas. Tank-type water heaters can operate scale-free only if all the calcium and magnesium carbonate are removed from the water prior to letting the water enter the tank. Water softeners are only partially successful in removing all scale-forming properties and are often inoperable due to lack of proper service and maintenance attention
Indirect fired water heaters do not need cathodic protection and are not susceptible to corrosion in potable water. Tank-type water heaters depend on coatings on the tank walls PLUS cathodic protection to prevent corrosion failures. If the anode is not checked and/or replaced at regular intervals, corrosion protection is lost.
Indirect fired water heaters have high recovery efficiency and the efficiency remains high. Tank-type water heaters may have high efficiency when new, but efficiency decreases drastically as the inside surfaces become insulated as layers of scale accumulates.
Furnaces
There many benefits to updating your gas blown furnace. The biggest being Reduced Energy Costs. As your heating and cooling system ages, it can lose its ability to cool or heat your home. If your current heat pump or air conditioner is more than 10 years old; or your furnace or boiler is more than 15 years old, it may be time to replace it with a more efficient system. Inadequate insulation or equipment installation may be the cause of temperature changes from room to room. Replacing your current equipment with an ENERGY STAR® rated heating and cooling systems can help reduce high energy costs as much as 10-30%.
There are several factors to consider when selecting a furnace:
What is BTU? A BTU is an acronym for British Thermal Unit and is the amount of heat required to raise the temperature of one pound of water by one degree in one hour. Furnaces are rated by their Btu input capacity. Air conditioners will remove 12,000 Btu’s of heat per hour per ton of cooling.
What is KW? A Kw (kilowatt) is a unit of power equal to 1000 watts. One Kw (1000 watts) will produce about 3417 Btu’s of heat. A 10Kw heating element, for example, produces 10 x 3417 Btu’s or 34,170 total Btu’s of heat. Each heating element size offered will also tell you how much heat it produces.
What is DOWNFLOW? This term refers to the furnace air delivery configuration. Downflow means the supply (warm) air is delivered from the bottom of the furnace into a duct system beneath it. Be sure to specify a downflow furnace when ordering as they are typically a different model number from the upflow/horizontal models.
What is HORIZONTAL? This term refers to the furnace air delivery configuration. Horizontal means the furnace will lay on its side for use in an attic or tight basement. All Goodman and Ruud furnaces are horizontal compatible and don’t require any modification whatsoever to be used in this manner.
What is UPFLOW? This term refers to the furnace air delivery configuration. Upflow means that the supply (warm) air is delivered upward, off the top of the furnace into an overhead duct system.
What is a BYPASS DAMPER? A bypass damper relieves the pressure created when one or more zone dampers are closed while another zone is calling for air. Imagine a two zone system with one zone closed – the furnace is still trying to deliver its full air capacity. The air volume that would have been routed to the now closed zone is “dumped” into the return air duct, preventing an over-delivery of air to the open zone.
What is a ZONE DAMPER? A zone damper is installed within your ductwork and controls air delivery to any given zone of your home. A butterfly valve contained inside the damper opens and closes as needed to regulate the air requirements of each individual zone.
What is 80% EFFICIENT? Also known as AFUE, or Annual Fuel Utilization Efficiency, this percentage number (80 in this case) represents the percentage of fuel that is converted to useable heat. The other 20% is exhausted out the flue or chimney. The current federal minimum for residential furnaces is 80% AFUE. Furnaces that are between 15 and 25 years old burn fuel at an average efficiency of about 65%.
Furnaces older than 25 years can be as little as 55-60% efficient meaning that between 40-45% of each dollar spent on gas is exhausted through the flue, providing no value to the homeowner. On average, an 80% efficient furnace will reduce fuel costs by about 23% when compared to a furnace that is between 15 and 25 years old. Purchase an 80% efficient furnace if you are in a southern climate or if you just wish to purchase an inexpensive furnace and still realize some savings on fuel.
What is 93% EFFICIENT? Also known as AFUE, or Annual Fuel Utilization Efficiency, this percentage number (93 in this case) represents the percentage of fuel that is converted to useable heat. The other 7% is exhausted out the flue or chimney. Venting requires 2″-3″ PVC, making installation of the flue a breeze. The current federal minimum for residential furnaces is 80% AFUE. Furnaces that are between 15 and 25 years old burn fuel at an average efficiency of about 65%.
Furnaces older than 25 years can be as little as 55-60% efficient, meaning that between 40-45% of each dollar spent on gas is exhausted through the flue, providing no value to the homeowner. On average, a 93% efficient furnace will reduce fuel costs by about 43% when compared to a furnace that is between 15 and 25 years old. Purchase a 93% efficient furnace if you are not in an extreme southern climate and if you wish to obtain maximum savings on your annual fuel bill.
What is 2-STAGE? A 2-stage gas furnace is like having two furnaces in one. On the coldest days, the furnace operates in the high-stage mode at 100% capacity. But on most days, the furnace comfortably conserves energy by operating in the low-stage mode at just 70% capacity. The 2-stage gas valve contributes to greater comfort by reducing temperature swings and maintaining even temperatures throughout your home. A 2-stage gas valves also run quietly on low stage 90% of the time, producing just 25% of the normal high-stage sound while significantly reducing energy consumption.
What is VARIABLE SPEED? A variable speed furnace blower motor is different from a standard blower motor in that it features a high efficiency Electronically Commutated Motor (ECM) by General Electric. These motors are simply the quietest, most efficient and powerful motors available for today’s furnaces. You will notice a marked increase in both system performance and comfort.
THE VARIABLE SPEED ADVANTAGE is provides lower energy costs, significantly reduced sound levels, eliminates the initial blast of air at each on-cycle, r0duces temperature variations from room-to-room and floor-to-ceiling, substantially increases humidity removal in the cooling mode.
What is LINESET? Also known as refrigerant lines, they are used in a split (an indoor furnace or blower and an outdoor condensing unit) cooling system to supply and return refrigerant between the outdoor condenser and the indoor coil. A line set consists of a smaller liquid line and a larger insulated suction line.
Heat Pumps
A heat pump is essentially an air conditioner with a few additions. A heat pump has a reversing valve, two metering devices and two bypass valves. This allows the unit to provide both A/C and Heat. The diagram above shows a HP (heat pump) in cool mode. The cycle goes like this; Energy Management starts at the top.
Heat Pump Cooling Mode
The compressor (1) pumps the refrigerant to the reversing valve (2).
The reversing valve directs the flow to the outside coil (condenser) where the fan (3) cools and condenses the refrigerant to liquid.
The air flowing across the coil removes heat (4) from the refrigerant.
The liquid refrigerant bypasses the first metering device and flows to the second metering device (6) at the inside coil (evaporator) where it is metered.
Here it picks up heat energy from the air blowing (3) across the inside coil (evaporator) and the air comes out cooler (7). This is the air that blows into the home.
The refrigerant vapor (8) then travels back to the reversing valve (9) to be directed to the compressor to start the cycle all over again (1).
Heat Pump Heating Mode
The difference in the two diagrams is the reversing valve (2) directs the compressed refrigerant to the inside coil first.
This makes the inside coil the condenser and releases the heat energy (3-4). This heated air is ducted to the Unit.
The outside coil is used to collect the heat energy (3-7). This now becomes the evaporator.
Ideally, we would like to design heat pump systems with “free” energy sources rather than supplemental sources (ex. boilers for heating the loop temperature). These “free” energy sources are found in outside air, river and lake water, ground water and soil. However, the vast majority of these systems are designed without these types of heat sources and heat sinks.
Lighting Technology Reduces Energy Cost
Evaluate lighting to determine energy and cost savings
New Technologies being utilized for Indoor Lighting can save on your facilities energy use and cost. These Technologies include new types of higher efficiency lamps and ballast. There are also improvements in control systems, such as occupancy sensors to turn off lighting when it is not needed. An indoor lighting audit will analyze your facilities’ needs and match new technology options to achieve 20 to 50 percent savings.
Indoor Lighting
Advance lighting solutions improve aesthetics and lighting while reducing energy consumption. Many new technologies reduce cooling requirements and improve color rendering to provide a high quality of light output.
Outdoor Lighting
Reduce crime problems, increase safety levels and reduce power consumption with an aggressive outdoor lighting program. Utilize decorative lighting to improve appeal and maximize your light efficiencies.
Quality lighting system provide high returns.
Indoor/Outdoor lighting solutions provide a 1-4 year payback. Financing options allow your energy savings to pay for your new lighting system – a lighting system which improves the appearance of your facility, reduces energy consumption and improves the quality of light.
