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What is an air-conditioned ready house?
Typically the refrigeration piping, an electrical junction box & condensate lines are "roughed in" in new homes. Be aware it still requires the purchase of the outdoor condensing unit and the indoor evaporator coil. Additionally, all the piping, refrigeration, condensate, and electrical disconnects have to be connected.

The importance of IAQ:
Respiratory ailments, often attributed to poor indoor air quality, represent the third largest cause of death in the U.S., ranking only behind heart disease and cancer, according to the American Medical Association. The Environmental Protection Agency has said that indoor air is often 7-10 times poorer than outdoor air quality. Airborne particles are divided into two classifications: coarse, or those particles larger that 2.5 micron in diameter; and fine, those particles 2.5 micron or less in diameter. For reference purposes, a micron is 1/25,000th of an inch in diameter! It is the fine particles, 2.5 micron or smaller , that our natural defense systems cannot eliminate. Individuals with health problems, such as allergies or asthma, need to be protected from poor indoor air quality, as do certain other groups such as the elderly or the very young, who may have compromised or underdeveloped respiratory systems. Problems with indoor air quality go beyond health related issues - productivity, absenteeism, product integrity and even one's sense of well-being may be adversely affected by poor air quality. There are three basic approaches to improving indoor air quality. You can (1) control or eliminate the source of pollutant, (2) dilute the contaminant, usually through ventilation, or (3) remove the contaminant from the air by filtration. You can't always reduce or eliminate the air contaminant source. Ventilation can be a good approach, but the source of contaminant may be in the outside air itself. Also, ventilation can raise the cost of conditioning the air, since you may be required to heat or cool more air than before. When control and ventilation are not practical, filtration becomes an important option. Filtration of sub-micron particles is not always easy. Most air-filters are not designed to remove the fine particles from the air stream. The filters that come standard with a house furnace, or even commercial heating and air conditioning equipment, are not efficient at the removal of the fine particles. In fact, they are designed to protect the equipment from the larger particles, and do nothing at all to protect occupants. When you need to remove harmful fine particles from the air, make sure you select a filter or filtration device that is specifically tested for its ability to remove very small particles. In a given sample of indoor air, about 98.5% of the number of particles will be 1 micron or smaller in diameter. If you need to remove sub-micron particles, make sure the product you are evaluating has been tested specifically for its ability to remove particles in the 2.5 micron range or smaller. Please call our sales department for further information

Mold & Health, Eliminating Mold, IAQ and Mold:
Mold, or fungi, lives in virtually any building, under sinks, in bathrooms, basements, refrigerators, or any damp dark place. At first, the mold is inconspicuous, or microscopic. After is has spread and completely covered the area with millions of cells you start to see the mold.

When considering mold, air filters serve the purpose of limiting the amount of spores in a given volume of air thus limiting the reproduction capabilities of the mold. Mold needs three things to survive, appropriate temperatures, nutrient (food sources), and water. All three of these items are indigenous to an HVAC system. Typically HVAC systems temperatures range from 85 F to 140 F. Airborne contaminants, including molds, can become nutrients for other airborne molds, and water may be common in the area of coils or actually introduced through humidifiers.

Proper application of Heating, Ventilation and Air Conditioning (HVAC) components per ASHRAE recommended practices serves to limit the possibility of contaminant growth within a system. The two most important considerations are the removal of contaminants (nutrients) and moisture. The presence of mold in buildings is becoming more common due to more airtight construction practices that improve insulation and energy efficiency but precipitate moisture in walls and ceilings.

Mold spores are well over one-micron in size and easily removed by applying air filtration according to ASHRAE recommendations. Even a pleated panel filter will have an efficiency against molds over 8%. One key consideration is that air must be moved through the filter for the filter to remove the contaminants. If elevated mold concentration levels are suspected, increasing air changes to the space may have a debilitating effect on the mold's reproduction. As more air is moved through the air filter the total space contaminant removal efficiency is increased.

If a health situation exists specific to a species of mold the application of proper air filtration with appropriate air conditioning system operation can severely reduce exposure. Some mold requires a higher level of filtration efficiency for removal of its smaller particle size.

The most important component of control is the limitation of water in the environment and in the HVAC system. ASHRAE recommends that spaces have a controlled humidity level of under 60%. Consistently exceeding this level is a prescription for problems. Try placing a slice of bread in a dish with some water and to a slice of bread on a dish alone and watch the result.

To prevent mold proliferation in your building:

1. Reduce indoor humidity by:

2. Controlling growth at the source:

REMOVE ANY SOURCE OF FREESTANDING WATER. If mold is discovered, fix the source of the problem. In most cases, the best level of control of contaminated materials is the complete removal of the contaminated items. This includes completely replacing wallboard, sheet rock and carpeting or damaged organic materials (wood bearing products). Light instances may be cured using a weak bleach solution. In this case, you must insure that the contaminated item be allowed to dry completely.

The control of mold in our environment requires diligence and the application of good building and HVAC system housekeeping practices. The key to air quality in any application is to maintain contaminant dosage at acceptable levels, whether the level is sensory or definitive based upon a health guideline. Air filtration always plays a major role in this arena.

Refrigeration System Sequence of Operation:
A good understanding of the basic operation of the refrigeration system is essential for the service technician. Without this understanding, accurate troubleshooting of refrigeration system problems will be more difficult and time consuming, if not (in some cases) entirely impossible. The refrigeration system uses four basic principles (laws) in its operation. They are as follows:

The refrigeration cycle begins at the compressor. Starting the compressor creates a low pressure in the suction line which draws refrigerant gas (vapor) into the compressor. The compressor then "compresses" this refrigerant, raising its pressure and its temperature (heat intensity).

The refrigerant leaves the compressor through the discharge line as a hot high pressure gas (vapor). The refrigerant enters the condenser coil where it gives up some of its heat. The condenser fan moving air across the coil's finned surface facilitates the transfer of heat from the refrigerant to the relatively cooler outdoor air.

When a sufficient quantity of heat has been removed from the refrigerant gas, the refrigerant will "condense" (i.e. change to a liquid). Once the refrigerant has been condensed (changed) to a liquid it is cooled even further by the air that continues to flow across the condenser coil.

The condenser design determines at exactly what point in the condenser the change of state takes place (i.e. gas to liquid). In all cases, however, the refrigerant must be totally condensed to a liquid before leaving the condenser coil.

The refrigerant leaves the condenser coil through the liquid line as a warm high pressure liquid. It will next pass through the refrigerant drier (if so equipped). It is the function of the drier to trap any moisture, contaminants, and large particulate matter present in the system. The liquid refrigerant next enters the metering device, which is a capillary tube. The purpose of the metering device is to control or measure the quantity of refrigerant entering the evaporator coil. In the case of the capillary tube this is accomplished through the size and length of the tube and the pressure difference present across the tube.

Since the evaporator coil is under a lower pressure than the liquid line (due to the suction created by the compressor), the liquid refrigerant leaves the metering device entering the evaporator coil. As it enters the evaporator coil, the larger area and lower pressure allows the refrigerant to expand and lower its temperature. This expansion is often referred to as "boiling". Since the unit's blower is moving indoor air across the finned surface of the evaporator coil, the expanding refrigerant absorbs some of that heat. This results in a lowering of the indoor air temperature, hence the "cooling" effect.

The expansion and absorbing of heat cause the liquid refrigerant to evaporate (i.e. change ot gas). Once the refrigerant has been evaporated, it is heated even further by the air that continues to flow across the evaporator coil.

The particular system design determines at exactly what point in the evaporator the change of state take place. IN all cases, however, the refrigerant must be totally evaporated to a gas before leaving the evaporator coil.

The low pressure (suction) created by the compressor causes the refrigerant to leave the evaporator through the suction line as a cool low pressure vapor. The refrigerant then returns to the compressor, where the cycle is repeated.

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