Latest commercial HVAC tech for hot climates?? New office build

[tonyhale]

I'm about to start a 42K square foot commercial office building, three floors. Initial meetings with MEP engineers in a few weeks, and I don't want to be relegated to whatever system they're pushing this month.

Our current office building that is smaller with older ducting has two 40T RTUs from Trane. They're 18 mos old, and we've gone through several igniters already, and had several other service calls. Before we bought new units, the old Trane RTUs were notoriously unreliable. If one went out, the whole floor would roast, and we had unhappy staff. We had a couple of issues that required parts that took a week to get in. That's unacceptable.

So my criticism of our current set-up is a lack of reliability, lack of fault tolerance, and poor parts availability.

In a new building, is there a middle ground between a single unit for a whole floor and a mini-split for every office? Is commercial VRF common these days? What's the best type of system for efficiency, fault tolerance, and reliability?

[comfortdoc]

VRF will suit well.

[slctech]

VRF will suit well.

I agree, if properly designed and installed.

VRF systems look REALLY easy on paper and a majority of the time during the bidding process are grossly under bid. So it is pertinent that your mechanical engineers work closely with the manufacturer of the VRF they choose or you desire and very pronounced installation stipulations are outlined for prospective contractors to bid on (use of ball valves, nitrogen purging, pipe supports, pipe bending, etc). Work with the local distributor of the equipment for suggestions on local contractors that they KNOW can do the installation properly and by the book. These companies have been vetted by the local factory person that comes in after the install to start-up and commissioning, actually make sure that it is stipulated that the system requires the factory not the contractor to perform the commissioning and start-up.

Most of us here have seen more than our share of VRF installations gone wrong, not that the contractor meant to hack it, but a month into the project reality sinks in that they grossly under estimated their labor costs.

Another fact that most people are not aware of when looking at building a new commercial building and utilizing VRF technology is the need to still meet codes for make-up air. Thus, in addition to a VRF system for the comfort heating and cooling needs of the building, additional equipment is required to meet the air quality codes.

A properly installed VRF system will work nicely and efficiently, but a poorly installed one will be the worst financial nightmare you ever lived through!