Cold and Chilled Line Insulation in Arlington, TX and the DFW Metroplex

Chilled water supply and return, condenser water where it needs it, cold process piping, glycol and brine loops, and refrigeration suction lines from the machine room to the air handlers. Pumps, valves and strainers on cold service get covered too — a bare valve on a chilled line is a condensation point that drips into whatever sits under it.

We work in mechanical rooms, above ceilings, on rooftops and in pipe racks. Outdoor cold lines get the same weather-lapped metal jacketing as hot work, installed over the vapor barrier without puncturing it — the jacket takes the sun and the hail so the barrier underneath never has to.

The physics is one sentence: whenever a surface sits below the dew point of the air around it, water condenses on it. In a North Texas summer the dew point lives in the 70s°F, so a 45°F chilled line is 30 degrees below it every hour the chiller runs. That water has to go somewhere — down the pipe, through the hanger, onto the tile.

The damage compounds quietly. Stained and collapsing ceiling tiles are the visible part. Above the ceiling, the standing moisture feeds mold, and against the steel it drives corrosion under insulation — the pipe rots from the outside in, hidden under material that looks fine from below. The full mechanics are in why cold pipes sweat.

And wet insulation stops insulating. The water bridges the surface closer to the pipe temperature, which condenses more water, which soaks the run further along. A cold line with a leaking vapor barrier gets worse on its own; it never gets better on its own.

On hot work the insulation is the point and the jacket is protection. On cold work the vapor barrier is the point. It has to be continuous over every foot of the run — every joint sealed, every seam lapped, every hanger and valve detailed. One break does not leak one spot: moisture drives toward cold, and a single open seam wicks water through the whole run behind an intact-looking surface.

So the barrier is where our hours go. Joints are sealed as they are made, not caulked afterward from the outside. Terminations get vapor stops, so if a section ever does take damage the water stays in that section instead of traveling. Fittings are fabricated to fit on our benches — a barrier that relies on tape stretched over a bunched elbow is a barrier for one summer.

Cold service gets closed-cell material — insulation whose cells do not connect, so the material itself cannot wick water even where the barrier takes a hit. Elastomeric foam is the workhorse on chilled water and refrigeration: flexible, its own vapor retarder, clean to fabricate around valves and pumps. Cellular glass is the heavy answer — rigid, rated −450 to 900°F, and it absorbs no water at all. It runs $28–48 per square foot installed and it is what we spec where the service is cold, wet, outdoors or all three.

What cold service does not get is fiberglass. Fiberglass on a chilled line soaks the first time the barrier is nicked, loses its R-value, and then holds that water directly against the steel — the corrosion-under-insulation case in one material. We strip and re-insulate chilled systems in exactly that condition, and the pipe underneath decides whether it was caught in time.

Thickness on cold work is not an energy calculation — it is condensation control. The outer surface has to stay above the dew point of the worst air it lives in, or it sweats no matter how good the barrier is. A line in a conditioned space needs less; a rooftop suction line in an August design condition needs more. We size each run for its actual environment, on the conservative side.

Our calculator runs the fuel math for hot systems — cold lines do not fit that model, so they get surveyed and quoted directly. The walk-down is free: we check surface temperatures with an IR gun, find where the existing barrier has failed, and you have a written number within 24 hours. The $1,500 job minimum applies, same as all our work.