Stacking Evaporator Coil Stages

In commercial HVAC, you will find several different types of multi-stage evaporator coils: intertwined (shown above), horizontal face split (one coil on top of another), and vertical (side by side).

When staging a horizontal evaporator, pay attention to ensure that stage #1 is on the bottom and stage #2 is on the top. If stage #1 is on top, you risk condensate being pulled off of the coil when the water runs down the wet fins and then hits the dry second stage on the bottom.

By keeping stage #1 on the bottom, the moisture adhesion will stay consistent as condensate drops, no matter if one or both stages are calling.

You can also have this same effect when stage #1 fails, and stage #2 keeps running on a stacked horizontal coil.

—Bryan

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Related Tech Tips

Tips for Server Room Conditioning
Server rooms, sometimes called data rooms, are a somewhat unique situation in the HVAC trade with some special circumstances that should be considered. Here are a few tips for success when working on equipment for these spaces. Note: this article is focused on smaller server rooms that may use conventional or mini-split-type forced air equipment. […]
Read more
A Simple Piping Practice
Although there are various line lift, sizing, and trapping guidelines depending on oil and refrigerant type, there is one guideline we can all understand easily and remember to apply. This guideline is to slope suction lines towards condensing units/compressors. Keeping the suction line sloped toward the compressor, especially with long overhead lines, helps return the […]
Read more
Shielded Control Cable & Communicating Controls
When I first started in the trade, we used to run into shielded control wires on the Carrier Comfort Zone 1 zoning systems and also on a Carrier VVT system I used to maintain at a bank. I knew it has something to do with electrical “noise” and that communicating systems often called for it, […]
Read more
loading

To continue you need to agree to our terms.

The HVAC School site, podcast and daily tech tips
Made possible by Generous support from