Slab Sensor Conduit Decision — Garage Hydronic Heating
Date: 2025-10-22 Location: 24′×40′ garage radiant slab (manifold on left 24′ wall) Subject: Installation method for hydronic slab sensor conduit
Background
During the pre-pour inspection of the radiant PEX installation, all supply and return loops were already routed through EZ Loop bend supports along the left wall. The radiant tubing was installed on an orange knobbed insulation panel system, and space along the manifold edge was tightly occupied by the existing PEX bends.
At this stage, a conduit for a future slab temperature sensor was still desired for potential thermostat or control upgrades. The challenge was that there was no open slot remaining at the manifold entry point for a clean, protected sensor conduit.
Evaluation
Three potential approaches were considered:
| Option | Description | Pros | Cons |
|---|---|---|---|
| 1. Add one extra EZ Loop for the sensor conduit | Slightly shift one existing PEX line (~1–1½”) and install an additional EZ Loop to hold a ½″ PEX tube used as a conduit for the future slab sensor. | Professional appearance, identical protection as other loops, easy sensor access later. | Requires small repositioning of one existing PEX bend. |
| 2. Run conduit adjacent to existing EZ Loop cluster | Insert conduit beside the current loops, entering slab at a 30–45° angle. | Quick, minimal disturbance. | Less secure, non-uniform entry path. |
| 3. Omit the slab sensor conduit | Skip installation. | No modification needed. | Loses future sensor option; less control precision. |
Decision
After reviewing layout constraints and the low effort involved, Option 1 was chosen as the optimal balance of quality, durability, and future-proofing.
✔️ Decision: Install one additional EZ Loop on the left manifold wall, shifting one PEX line slightly, and run a ½″ PEX conduit through it for the slab sensor.
Implementation Notes
- The conduit will be labeled “Sensor Conduit – Do Not Connect.”
- The ½″ PEX conduit will extend 10–14 ft into the slab, centered between two heating loops, and 2″ below the slab surface.
- Both conduit ends will be taped and secured prior to the concrete pour.
- Sensor wire will be added post-pour if radiant control upgrade occurs.
Outcome
This solution preserves the current hydronic layout, maintains a professional and uniform appearance at the manifold wall, and ensures future flexibility to add a radiant floor temperature sensor with no structural modification required.
Related Documents
- Utilities & Conduits - Utility and conduit coordination
- Initial Build - Construction progress tracking
- Garage HVAC and Heating - Radiant heating system design
- Mechanical Room - Heating system components and controls