Fairfield HVAC Pros (707) 243-8706 – Fairfield, CA
HVAC has a significant effect on the air quality in any mechanical structure. For the air to be circulated properly in a building the ventilation system needs to be carefully engineered to address such problems as proper ventilation, effective volume of air to be circulated, and its optimum temperature or pressure. While a large industrial unit may have separate ventilation systems for exterior air and ventilation for the air in its interior, in a plastics manufacturing facility, for example, the air is almost always a mixture of fresh outdoor air and recycled air.
In all mechanical structures, if the air exchange surface is not properly protected against moisture, the air exchange area will be subject to the growth of mold and mildew. Mold can cause respiratory illnesses such as asthma, allergies, and poor lung function. Of course, mold and mildew can also defuse the free outdoor air and promote decay and degradation of materials.
The areas where a mechanical structure connects to the insulated materials conducive to positive air pressure are called 000 lets and their exposure is well documented, although the best evidence to date is on the internal combustion engines. In the past few years, there has been a large improvement in the design of insulation materials, and as such, there has been a marked improvement in how efficient the systems maintain the interior air burden that is between humans and the interior materials.
For example, insulation materials themselves distributed keeping in mind that they should do their job without a large amount of free space on their surfaces. You get much more insulation through simple design and plain published building code. If your HVAC system is centrally located in an area that has a moderate climate, and air load calculation will be inaccurate. In colder climates such as Chicago, an objective analysis of the air delivered through air ducts of a 2 ft. high steel-insulated duct system is usually considered adequate but there are other design considerations. The insulation is inside structural plastics or any material that will form a part of the insulated mechanical ventilation system.
Of course, there is additional insulation consideration for the frame of the duct system, but this is subject to design and cost. The only available method to measure the air load is with a discerning load calculator. HVAC systems have only two sources of air passes and the loss of air is generally due to internal friction, flue leakage, or through the insufficient mechanical design of systems or excessive air infiltration.