Commercial Hydronic Fan Coil Installation & Replacement in Southern California and Arizona

What is replaced in a hydronic fan coil project?

The terminal unit and the parts that make it work: coil, fan and motor, drain pan, control valves, piping connections, and zone controls. Chilled and hot water come from the building’s central plant, so the unit itself has no compressor.

A fan coil moves room air across a coil fed with chilled water, hot water, or both. Two-pipe units switch one coil between heating and cooling when the building changes over for the season; four-pipe units carry separate circuits and can do either at any time. Our scope is the fan coil, its valves, and its controls. The central plant, including the chillers, stays outside it. For a primer, see hydronic fan coils: what facility teams should know.

When should new fan coils be installed?

When a floor is re-planned into more rooms, an existing zone gains people or equipment heat, or a space is brought onto the building’s chilled and hot water for the first time.

New terminal units add load to the plant and the risers. Building engineering should confirm capacity and flow before the units are ordered. It is far easier to learn about a riser limit on paper than after the ceiling is open.

When does replacing a fan coil beat repairing it?

When coil leaks return after repair, the drain pan has rusted through over a finished ceiling, motor parts are no longer made, or the valve body has seized. One accessible leak or a failed actuator is usually a repair.

Component	Often repairable	Usually points to replacement
Motor	A replacement motor is still available	Obsolete motor on an aging cabinet
Coil	A single, accessible leak	Repeat leaks or heavy fin loss
Drain pan	Surface corrosion that cleans up	Rusted through over finishes
Control valve	Actuator failure	Valve body seized or sized wrong

A remodel that changed how the space is used can also leave a healthy old unit wrong for the new load, which makes replacement a sizing decision rather than a repair one.

Why should the control valve be evaluated with the unit?

Because a new cabinet on an old valve inherits the old problem. A stuck or oversized valve makes the unit hunt, overcool, or push more flow than the coil can use, so the zone heats and cools against itself.

Two-pipe systems add a second trap. The building’s changeover decides whether the unit heats or cools, and controls set up with four-pipe logic will fight it. We install and service controls, so the new unit can be wired into the zone controls and report correctly from the day it starts.

How is fan coil work run in an occupied building?

As ceiling work above people who are still working. Plan the removal path, confirm the riser and branch isolation valves close, protect the finishes, and agree on a work window the tenant can live with.

1. Survey ceiling or closet access, finishes, and the removal path.
2. Confirm riser and branch isolation; without working valves, one unit means draining a riser, and everyone on it loses conditioning.
3. Pull the permit. Kelly Purcell, our Installation Director, specializes in permitting under California’s city-by-city system.
4. Remove the old unit with the space below protected.
5. Connect piping, drain pan, trap, and condensate.
6. Vent the coil on refill and check flow, because an unvented coil delivers a fraction of its capacity.
7. Integrate controls and update the asset register.

In buildings with many units of the same age, replacing by riser or by floor keeps drain-downs to a minimum and spreads capital across budget years.

Who does the work, and who coordinates with building engineering?

Install Foreman Anthony Renteria leads our installation team on the job. Where building engineering runs the plant, isolation and changeover timing should be agreed with them so the project runs on one schedule, not two.

That single schedule is what our Eliminate Red Tape commitment looks like in a managed building. Our technicians are factory-trained, and REE Mechanical Inc. carries the licensing, bonding, and insurance the work requires. See property management for how we work with managed properties.

What affects the scope of a fan coil project?

Unit count, two-pipe or four-pipe configuration, ceiling access and finishes, valve replacement, riser isolation and drain-down, controls integration, and the work windows tenants allow. Coordination with building engineering shapes the schedule as much as the equipment does.

• Count and configuration. Ten identical units on one floor plan differently than a mix of sizes across several floors.
• Ceilings. Demolition, patching, and protection of finishes in occupied rooms.
• Valves. Control and isolation valves replaced with the unit, or not.
• Risers. Drain-down and refill, plus venting every coil on that riser.
• Hours. After-hours work and tenant notice periods.

Where does REE Mechanical install and replace fan coils?

In commercial buildings from Ventura County to San Diego County, and in Arizona. Start with Los Angeles County or San Diego County, or see all service areas.

How do you get fan coil replacement scoped?

Call (800) 742-0910 or send the floor and unit count. Related: water-source heat pump installation and replacement. After installation, a preventive maintenance and tune-up program keeps drain pans, valves, and filters from repeating the old failures.