Pentair THS4296 Filter Replacement | DSPS-Reviewed Project
This Pentair THS4296 filter replacement was completed as the second phase of improvements to a heavily used Wisconsin public swimming pool. Pool Envy® performed the installation in accordance with a DSPS-approved engineered plan set, increasing available filtration area while improving the operating characteristics of the existing circulation system.
Regulatory & Plan Review
This filter replacement was completed in accordance with engineered plans prepared and sealed by a Wisconsin Licensed Professional Engineer and reviewed and approved by the Wisconsin Department of Safety and Professional Services (DSPS).
The project was subject to applicable Wisconsin public swimming pool plan-review requirements under Wisconsin Administrative Code Chapter SPS 390 . Pool Envy® performed the filter installation and associated mechanical alterations in accordance with the approved construction documents. Professional engineering services associated with the project were provided independently by the Wisconsin Licensed Professional Engineer.
Following completion, the installation was inspected and subsequently approved by the Wisconsin Department of Safety and Professional Services.
Project Summary
The leisure pool operates approximately 12 hours per day, seven days per week and experiences substantial bather load and sustained circulation demand. The existing filter provided limited operational margin and required frequent backwashing as filter loading and differential pressure increased.
The planned improvement replaced the existing commercial filter with a Pentair THS4296 horizontal filter. The larger filtration area provided additional operating capacity while allowing the required circulation flow to pass through a greater media surface area.
Public leisure pool served by the commercial filtration system.
Existing Commercial Pool Filtration Conditions
Prior to the filter replacement, the existing circulation system presented several operational limitations:
- An existing filter with approximately 19.3 ft² of filtration area.
- Frequent backwashing as filter loading and differential pressure increased.
- Limited operating margin during periods of heavy pool use.
- Evidence consistent with uneven media loading and channeling.
- An older filter model that was no longer being produced by its original manufacturer.
- Increasing maintenance demands associated with continued operation of the existing filtration system.
The filter replacement formed part of a phased facility improvement project. Pool Envy®'s role was to perform the approved mechanical alterations and equipment installation while coordinating the work with facility operations to reduce unnecessary downtime.
Existing commercial pool filtration equipment prior to replacement.
Pentair THS4296 Filter Replacement
In accordance with the approved plan set, the existing filter was replaced with a Pentair THS4296 horizontal commercial pool filter. Pentair identifies the THS4296 as having 26.7 ft² of effective filtration area.
Compared with the approximately 19.3 ft² filtration area of the previous equipment, the replacement provided substantially more media surface area for the circulation flow used by the facility.
- 26.7 ft² of effective filtration area.
- Increased filtration area relative to the previous equipment.
- Lower filtration rate per square foot at an equivalent system flow.
- Additional operating margin for a high-use commercial aquatic facility.
- Compatibility with Pentair commercial backwash-control configurations.
Additional manufacturer specifications for the THS Series are available directly from Pentair's THS Series commercial filter documentation .
Pentair THS4296 during installation with the project plan set.
Completed THS4296 installation in the aquatic facility mechanical room.
Glass Filtration Media
The replacement filter was commissioned using Vitroclean® glass filtration media as specified for the project. The media formed part of the approved filtration configuration installed within the THS4296.
Selection of filter media, equipment sizing, hydraulic requirements, and other professional design determinations were established through the project's approved construction documents. Pool Envy®'s responsibility was the installation of the specified equipment and mechanical components in accordance with those documents.
DSPS-Approved Engineering Documents
The commercial pool filter replacement was performed in accordance with a plan set prepared and sealed by a Wisconsin Licensed Professional Engineer and approved through DSPS plan review.
The approved documents established the project requirements for the filtration equipment and associated mechanical alterations. Pool Envy® performed the field installation in accordance with those approved documents rather than providing or offering professional engineering services.
Commercial Pool Filter Installation Video
The following video shows portions of the existing-filter removal, rigging, placement, and installation of the Pentair THS4296 in the mechanical room.
Results of the Filtration Upgrade
Following completion, the larger commercial filtration system provided the facility with greater available filtration area and additional operating margin. Operational observations following the upgrade included:
- Improved observed water clarity during facility operation.
- Increased available filtration area for the required circulation flow.
- Lower filtration rate per square foot compared with the previous filter.
- Reduced frequency of backwashing observed during normal operation.
- Improved operating margin for a heavily used public swimming pool.
This Pentair THS4296 filter replacement represented the second phase of a coordinated mechanical-system improvement project. An earlier DSPS-reviewed heater bypass correction prepared the circulation system for the subsequent filter installation.