HVAC

Overview

The building is serviced by five 5-ton standard HVAC units housed in the church attic. Physical access for these units is through a drop-down ceiling ladder in the Right overflow room. Separate mini-split units service the Office and Right-Paw classroom. Condensers for all seven units are located on the pad behind the office, the pad behind the Right-Paw classroom, and the pad on the Nursery Patio. (See the zone map below. See Physical Security for the lock code for the condenser pad on the Nursery Patio.) Each of the seven units is connected to a thermostat which controls it's functions.

HVAC Zones

The five 5-ton HVAC units provide services to the following building zones via air ducts. (The main auditorium is serviced by two independently controlled units although they share common space.) Mini-split units blow air directly in the Office and Right Paw classroom Zones are color marked below. This zone map also shows the locations of thermostats and condensers.

There is no HVAC provision for the main entrance or lobby of the building.

CVCC HVAC Zones PDF

Right and Left Paw (Office) Minisplits

The HVAC units in the Right and Left Paw classrooms are single-stage Mitsubishi MSZ-GE12NA-9 mini-split heat pumps. There is no AUX HEAT capability with these units.

These units come standard with a wirelesss remote control as their default control unit. The wireless remote controls for these are not used and are stored in the church office. Instead, these units have been outfitted with an interface module that sits on top of each mini-split that interfaces with a standard thermostat. These interface units make the mini-splits appear to the thermostat as a conventional air conditioner rather than a heat pump. Thus, the thermostats for these mini-split heat pumps must be configured to interface to a conventional AC rather than to "heat pump". (On the Venstar thermostats, DIP switch 3 must be set to "GAS/EL" rather than "HP".)

Five Ton Attic HVAC units

All HVAC systems, with the exception of the Paw Minisplits, are 5 ton York YHJF single-phase heat pumps with air handlers in the attic. There is no AUX HEAT capability with these units.

Each 5-ton unit in the attic has two water trays to handle condensation: a primary and a secondary tray. Water from the primary tray has two drain pipes: a primary and a secondary drain pipe. The primary drain pipe is positioned at a lower elevation in the primary tray than the secondary drain pipe. Under normal conditions water will run as follows:

First, water will run from the primary trays to the two vertical PVC pipes that are outside the building. Both of the vertical pipes are from the primary drain system. Three primary trays are connected to one of the pipes, and two trays are connected to the other. Water dripping out of either or both of those two vertical pipes is a good sign that condensation is draining properly.
If the primary drain pipes are not draining properly, the primary tray will continue to build up water. Eventually the water will exit the primary trays via the secondary drain pipe. The exit point for the secondary drain pipe is under the eave next to the two primary drain pipes. (A WIFI access point cable runs into the attic at the same point.) When we see water coming out that eave port, that’s our clue that the primary drains are not working as designed.
I believe the secondary trays are designed to route water through the secondary egress port under the eave as well.

HVAC Switches and Circuit Breakers

The seven HVAC systems are serviced electrically by circuit breakers that are next to the various HVAC condensers outside. In addition, the HVAC units in the attic each have an on/off switch that controls electrical to the units.

Thermostats

All seven heating/cooling systems are controlled by WIFI-enabled Venstar Colortouch thermostats.

Thermostat Sensors

Each thermostat features an on-board thermometer that is used to sense service area temperatures. In addition, some thermostats feature a remote wired or wireless sensor, as follows:

Thermostat Wiring

Blue or Black – C – Common wire

Red – R – 24VAC power

Green – G – Fan

White – W – Heat

Yellow – Y – Air conditioner

Remote Control of Thermostats

All thermostats are controllable remotely through the Venstar smartphone application and via browser on Skyport Cloud Services. See https://venstar.com/ for more information.

Stu Warford is the church's administrator of Skyport Cloud Services user accounts. A number of church members have user accounts that allow them to remotely control HVAC thermostats.

CVCC HVAC User Documentation PDF

Programmed Schedules

Thermostats are configured with program schedules which automatically enable HVAC services during worship services and other times when the building has regularly scheduled functions.

Temporarily Overriding Programmed Schedules

All thermostats are configured with an “override” function which can be used by anyone to temporarily override the scheduled functions during unscheduled times when the building is being used. Functions available during an “override” include:

Override duration – Allowing the system to be “on” temporarily from 30 minutes to 4 hours.
Target temperature

Configuring Thermostats

All thermostats can be configured locally or remotely. All thermostats are configured with a passcode that must be presented in order to configure the thermostat locally (manually at the thermostat). Note: thermostat configurations should only be performed by persons familiar with the church’s HVAC and WIFI systems.

HVAC Service

The church contracts with the following firm to provide periodic maintenance services:

Vacco – Ventura Air Conditioning Company
4665 Ortega St
Ventura, CA 93003
(805) 644-2665

Maintenance services are provided quarterly. Each maintenance service includes replacement of all five filters (MERV 13, 18X25X1).