The process of disinfecting the HVAC system entails a whole procedure that demands the application of disinfecting foggers together with the appropriate positioning of the saddle valve. This can be made possible through the application of the Hydrofogger. In this scenario, the customer can get information about the appropriate disinfectants to apply depending on the type of fogging required.
Understanding Antimicrobial Foggers
The foggers also have to be tested for droplet size as well as the compatibility of the chemical compounds used as a formulation for the foggers. For example, the antimicrobial fogger produced by the company Hydrofogger produce droplets ranging in 5-50μm and can treatment the ducting as well as the room in 10-30 minutes and reduce the bioburden up to 3 logs in many tests carried out at the facilities.
Types of Antimicrobial Foggers
“You would choose between the thermal foggers designed for vaporizing solutions for penetration purposes, the ULV cold foggers producing 5-50μ droplets for surface and airborne control, and electrostatic sprayers used for charging droplets for improved surface adherence; meanwhile, the Hydrofogger offers the designs of their ULV foggers specifically for HVAC systems and their thermal foggers specifically for odor control purposes; when designing the process to take place, the saddle valve should have the ability to support the possibility of continuous feeding.
Thermal Foggers: Thermal Foggers are used as a deeper penetration product when the insulation type has porous components.
Ultralow volume Foggers: 5-50μ droplets that can penetrate the coils and the plenums. They were
Benefits of Using Antimicrobial Foggers
Antimicrobial foggers can rapidly and uniformly dispense the product through ducting and rooms, thereby slashing the total duration required for wipe-downs by several hours; the studies performed in the field demonstrate that when the requirements for contact time and concentration are met, the process of fogging can generate multi-log reductions at the surface when combined with the use of automatic dose delivery systems and saddle valves.
When applying the process for fogging, the following planning for validation and safety should be considered: the pre- and post-procedures for ATP or culture swab tests should be conducted for the effectiveness of the process validated, the contact times should be documented (usually 10-30 minutes for ULV and appropriate chemistries), and the schedules of the HVAC fans should be coordinated to enable the contact time in the ducts. In this scenario, the appropriate PPE should also be worn and the area accessed should be isolated from entry until the residues are removed. On the other hand, when applying the process of fogging, the following should be considered:
To prevent any leakages during the treatment of the antimicrobial foggers, the valve seals, positioning, and torque requirements must satisfy the specifications of the system. Ineffective systems permit the aerosol to drift around the coils and find its way to the return ducts. Each should be tested at the operating pressure for 15 minutes. Inspection can follow at the joints by utilizing the electronic leak detector or the soap solution technique. Finally, in the disposal of the waste water produced in the treatment process when the hydrofoggers are in operation:
Kinds of Valves Utilized in HVAC Systems
Valve selection should be made depending on the functions together with the operation requirements since different functions such as the shut-off functions and safety functions require different valve styles. After the flow control requirements are identified, the material and the operating pressure should be considered.
- Ball valves: 1/4-turn for quick shutdowns and leak-tight isolation.
- Butterfly valves – for large ducts and proportional flow control;
- Globe valves: These are used as precise flow control devices for hydronic loops.Saddle valves: For connections to taps or humidifier installations.
Importance of Saddle Valve Installation
In actuality, many technicians are finding that more and more of the saddle valves employed for slitting are being replacesd by the use of the service valve/compression tee: the effectiveness of the compression fittings precludes the possibility of leak points, stress concentrations, and repair issues. In the event the saddle valve must be employed, torque clamps should follow the manufacturer's guidelines. Installing stainless steel fittings and utilizing the correct type of sealants for the threaded outlets will improve the tap designation to enable easier isolation or protection of the tap during the Antimicrobial Fogger treatment procedure facilitated by the HydroFogger team.
Step-by-Step Manual for the Disinfection of HVAC
Close the sequence: Isolate the zones, evaluate the saddle valve or refilling station, power down the fans and compressors, form the containment devices and PPE equipment available, deliver the calibrated antimicrobial fogger as per the manufacturer's instructional label directions, wait for the contact time to expire, purge the space with filtered air for 20 minutes to remove at least 3 logs. This would usually involve 10-30 minutes of fogging and 30-60 minutes of contact time.
Preparation for disinfection
Close the system to prevent someone from bypassing the system, lock out the power sources, and close the return grills; look for obstructions in the access panel and drainage lines. Investigate the saddle valve locations if the plan intends to use the water from the building as the injector; tighten the clamps and check the leak at 15 psi. HAZMAT provides N95 respirators or PAPRs, protectors for eyes, and chemical-resistant gloves and develop a flow characterization to promote the positioning of the fogger and the enclosure to increase exposure of the coils, drain pans, and plenums.
Using the Antimicrobial Fogger
Position the antimicrobial fogger in the return plenum or in the AHU to ensure that the fog reaches the coils and the drip pans; the output rates and dilutions required for the Hydrofogger depend upon the droplet size desired to avoid wetting the electronics. Use the recommended output rates until the desired volume or visible misting has been achieved—the recommended treatment time for 1,000 to 5,000 ft³ sized zones ranges from 10 to 30 minutes.
For greater details, select a fogger nozzle that has 5-50-µm droplets at the ULV output to create a balance between surface distribution and hang time in the airspace. Ideally, aim at equal distributions by pointing the nozzle at the coil sections and pulsating the treatment process for the more complicated plenums. Temperature and humidity should not pass unnoticed because the higher the humidity of the atmosphere, the longer the hang time. In the final phase of treatment, the filter should have a rating of the MERV13+ category during the 20-60 minute purge stage.
Tips for Effective Disinfection
Pressure-test the saddle valve installation at the pressure found at the building (usually 20- to 60-psi), and repair any leaks before treatment.
Use your antimicrobial fogger with a droplet size ranging from 1-5 µm, and the contact cycling times should be set between 15-30 minutes. All procedures should be documented in the maintenance log of the Hydrofogger.
After the fogging procedure, the purge systems should run for 20-60 minutes. The filters should also be replaced by filters that are at least MERV 13+ or HEPA. ATP or swab tests
Frequency of Disinfection
Fogging should be carried out at 3 months' interval in general business environments. In health-related grievances or high-occupancy installations, the frequency should increase to monthly. This can increase to biweekly as the situation dictates when the following factors are involved: biofilm and odor. The procedure for chlorination should occur following water invasion and repair work carried out in the ducting or the roofing. The event recording capability of the Hydrofogger should relate the procedure used for health-related grievances.
Safety Considerations
Ensure the occupants are removed during the operation of the antimicrobial foggers, limit the use of the involved HVAC zones, and perform the lockout and tagout procedures for the electrical control panels. Employ the use of a respirator (N95 respirator for limited procedures or elastomeric/P100 respirators for longer exposure), chemical-resistant gloves, and protect eyes as described in the MSDS procedure for the Hydrofogger. Ensure the saddle valve used for the foggers does not permit the entry of the fog product into the potable water lines and ventilate the area 30-60 minutes post-treatment.
In high-risk environments, the use of a full face respirator equipped with P100 filters and chemical-resistant gloves should be mandatory; lockout and tag-out procedures should also be implemented. Airborne concentrations should also be monitored utilizing aPID or particle counter and should remain below the permissible exposure limits defined in theUSOSHA PELs (100 ppm for solvent VOCs), and surface swabbing or ATP analysis pre- and post-treatment. Replacing the filters (MERV 13+ or HEPA) should be done following the fogging procedure. Factors During the Disinfection of HVAC Systems Access has to remain accessible, airflow should remain adequate, and risk of occupancy should remain minimal before the application of the antimicrobial fogger because the ability to reduce airborne as well as surface microbes up to 90% has been shown in studies when the droplet size spectrum of 10-50 µm can be achieved. ACH should also be recorded. The present designs of the hydrofogger support the generation of variant droplet spectra and pre-programmed cycles. System Access: Make sure service panels and grilles are accessible for the mist from the foggers to reach the coils, plenums, and return trunks. Compatibility: Make sure the disinfecting product has been tested for safety on the metals and other materials in the HVAC system. Contact time requirements can sometimes range from 10-30 minutes. Ventilation rate: Record ACH. Typical office spaces: 2-6 ACH. Health care: 6-12+ ACH. This will establish. Let the saddle valve placement, condensate drainage routes, and trap performance be sufficient to prevent cross-contamination during the chemical injection and correct functioning of the antimicrobial fogger. System Type The equipment must satisfy the treatment. Large plenums in unit roofs and RTUs alike happily accept the antimicrobial fogger mist compared to the smaller VAV boxes or PTACs. For example, in a 12-inch face coil unit with 8-14 fins per inch, the 10-50-micron droplets can reach the surface compared to the fan-coil systems in order to access the chemicals. Environment Occupancy rates should be factored in together with humidity and temperature; however, relative humidity above 60% makes droplet fusion more likely and suppresses distribution. In the health service area because the fact that ACH rates exceed 12, the antimicrobial fogger treatment can only be considered during terminal discharges. In office space set up 2-6 ACH pattern foging. Calculate the contact and purge time based on room volume and ACH: for example, in a 200,000 cu. ft. warehouse at 3 ACH rates 45 minutes of fogging and 60 minutes of purge to establish surface contact. Then check the procedure correct utilizing ATP tests or plate culture tests. In addition to the above steps, zone the HVAC areas containing the systems, close dampers wholly, and ready the PPE equipment equipment so that the individuals are protected as the disinfecting solution struggles to get back to the important zones.
Advantages and Disadvantages of the Use of the Antimicrobial Foggers When the advantages and disadvantages of utilizing the antimicrobial foggers are considered, balance the convenient coverage of the system compared to the probable exposure during use or construction of the available systems today from the companies like the Hydrofogger. Besides the advantage derived from the actual treatment stage following the fogging cycle, the probable reductions achieved through the level of microbes obtained (usually 2-3 log reductions of the microbes present) must also be factored in. Advantages Rapid and uniform delivery to coils, plenums, and hard-to-reach areas together with 2-3 log (99-99.9%) reductions can be achieved. This follows the fact that the calibrated systems available in the Hydrofogger allow dosage. This provides shorter shutdowns of 30-60 minutes compared to the wiping procedure. Hence, the fogging treatment can become more economical when compared to the wiping procedure. Disadv Has the potential for residualespecially when not cleaned through physical means; improperly installed saddle valves can generate potential leaks that can develop contaminants within the system or void product warranties. In the case of chemical disinfectionants, the systems must be shut down and PPE must be used. In more detail, one can expect tests of the materials and sensors available in the coil and the requirements for the contact time (commonly referred to as 10-30 minutes) and relative humidity specific to the chosen chemical formulation. Lessen the risk through observance of recommended plumbing principles (excluding modifications in the saddle valves), the Hydrofogger procedure, and diagnostic tests following treatment to establish the efficiency. Conclusion You must ensure correct saddle valve installations and the use of the antimicrobial fogger as per the manufacturer's specifications, verification of the check valve seals and the isolation of the system in place, correct distribution of the fog and the time exposure to the systems as per the specifications of the product used. A: Perform a systems assessment and select an EPA-registered product and fogger approved for use in HVAC systems. Warn occupants and limit access to the treatment area.
Use proper PPE (respirator, gloves, safety glasses), following the label directions specific to the chosen antimicrobial fogger. Seal sensitive sensors and electrical components, placing the fogger in the return plenum as directed for product distribution. Run the air handler as directed to distribute the fog through the ducts. This should continue for the recommended contact time. The following steps include ventilating the system and space until airborne residues are reduced to safe levels and verification of area cleanliness as determined through ATP or swab tests. For the hydrofogger, it is recommended that the user follows the label directions and maintains a log of lot numbers and concentrations as recommended. A: What are the proper procedures and safety practices considered during saddle valve installations for the delivery of disinfectants or water to the HVAC treatment system? A: Choose a straight and easily accessible pipe area that has the same specifications as the materials used for saddle valve installations and avoid connections and corroded areas. Deflate and drain the system as required. Clean the pipe surface, and following the directions of the valve manufacturer, orient the saddle clamp. Fasten the saddle valve clamps snugly. Use the identified pilot drill bit to drill the holes and slowly turn the valve handle as the valve slowly opens. Add the isolation shutoff valve and back-flow preventer or check valve based on the regulatory requirements. Use the thread-sealing material or PTFE tapes only if the manufacturer recommends. Verify the existence of leaks under the operating pressure. For chemical feeding systems rather than potable water systems, the saddle valve should be connected to the water meter output by the use of the metering pump or approved tap provided by the manufacturer. When in doubt about materials and regulatory requirements for the saddle valve system, the services of the certified Hydrofogger or licensed plumber should be contracted.
Q: What are the maintenance steps that can validate the effectiveness of the HVAC disinfection process and valve installations? A: A program of routine maintenance should be developed to validate the following: visual checks of coils, pans, and ducts; filter changes as scheduled; verification of residues of the antimicrobial compounds or ATP swabbing as per treatment protocols; functional verification of the antimicrobial fogger (condition of the nozzle and dose delivery accuracy and timer functions), as well as the operation of the isolation valve and the saddle valve; verification of the status of the saddle valve locations for corrosion and torque status; recording of treatment carried out, concentration used, and verification; and SDS chemical storage and handling procedures. Cleaning should be carried out when the system indicates the detection of microbes. Validation should also be carried out at predetermined intervals or during the analyses of indoor air quality. For more complicated procedures or calibration, the services of certified service technicians should be used.
