McDaniel Metals DDNECNJ90150 Installation Manual

281-987-8400 • 281-987-9494 (fax)

1318 Buschong, Houston, TX 77039

www.mcdanielmetals.com

DDNECNJ90150

DOWNFLOW JADE ECONOMIZER
FITS DAIKIN DCG090-150, DCH090­150, DCC090-150

to cool the space. (Go to step 5.)

4. Outdoor air dampers open to minimum posion and the
compressor engages to provide mechanical cooling.

5. When the thermostat is sased the outside air dampers
return to a closed posion.

ECONOMIZER 101

Economizers are designed to provide “free” air condioning
when outside condions are appropriate. When the outside air
is cool and dry enough, the economizer automacally opens to
introduce the cool air to the interior space, thereby eliminang
the need to run the air condioning compressor.

If the outside air becomes too warm or humid, the economiz-

er automacally closes the fresh air damper and the compressor
engages to begin cooling the space mechanically.

If a two stage thermostat is used it is possible to use a combi-

naon of economizer and mechanical cooling to condion the
space.

The economizer can also be set to allow a minimum amount
of fresh air to enter the space when the equipment’s indoor

blower is operang. Economizers are valuable tools to enhance

indoor air quality, save energy and prolong the life of the air

condioning equipment.

SEQUENCE OF OPERATION

This sequence assumes employment of a single enthalpy

economizer using a two stage thermostat.

1. A call for cooling comes from room thermostat.

2. The enthalpy sensor determines if the atmospheric condi-
ons are conducive for using outside air for cooling. If YES,
go to step 3. If NO, or if outdoor air temperature rises above
enthalpy set point, go to step 4.

3. The outside air dampers open and modulate to maintain a

mixed air temperature (outside air + indoor air) of 53 de­grees F. If the outdoor air is insucient to sasfy the ther­mostat alone and a second stage of cooling is required, the

rst stage compressor starts and works in conjuncon with

the economizer

Figure 1

INSTALLATION

1. Open carton and inspect contents for shortages and damage.

2. Remove large evaporator access panel from package unit
and discard. Remove the smaller lter access panel and the
horizontal return panel.

3. Slide the damper rack into the large opening and pivot the
damper into posion around the post between the evapora­tor opening and the lter access opening. (Figure 1)

4. Posion the dampers in the opening unl the front anges
are ush with the corner post and divider post between the
lter access panel and the evaporator access panel. (Figure 2)

Figure 2

REV. B Effective 3-28-2014

5. Feed the pink wires for the mixed air sensor through the unit
economizer plug mousehole into the blower secon of the
unit. Mount the mixed air sensor to the blower housing away
from the center to avoid interferring with the rotaon of the
blower wheel and plug in the wires. (Figure 3)

6. Aach the pink mixed air senor wires to the controller. (Fig-

ure 4)

7. From the horizontal return opening, plug 9-pin economizer
plug into matching 9-pin plug in the unit.

NOTE: Ensure neither the wire nor the plugs interfere with the

movement of the dampers during operaon.

8. Replace the horizontal return cover.

9. Install the new evaporator access panel on the unit.

10. Secure access panel to the unit with the screws from step 2.
New holes must be drilled to secure the panel to the 12.5 ton
unit.

11. Assemble the barometric relief hood and the fresh air hoods
with the screws provided. Be sure to install the mist elimina­tors before installing the front lter access piece. (Figure 6)

12. Install gasket material on the economizer panel outside
of the hood openings using the hood mounng holes as a
guide.

13. Refer to enclosed documentaon for the Jade controller for
set up.

14. Use the minimum set point equaon (see below) to deter­mine the minimum posion seng on the controller.

15. Install barometric relief hood with screws provided through
access panel and economizer.

16. Install the fresh air hood with the screws provided through
the access panel and economizer.

17. Install the blocko panel above the hoods on the 12.5 ton
unit. (Figure 5)

18. Run a bead of silicone or other approved sealant along the
hood anges to ensure a waterght seal.

19. Replace lter access panel.

Figure 4

Figure 5

Figure 3

MINIMUM SET POINT EQUATION

(To X OA) + (Tr X RA) = Tm
To = Outdoor air temperature
OA= Percent of outdoor air
Tr = Return air temperature
RA= Percent of return air

Tm= Resulng mixed air temperature

Example:

Fresh air required is 10% outdoor air.
Outdoor air temperature is 60 degrees F.
Return air temperature is 75 degrees F.
(0.1 X 60) + (0.9 X 75) =

6.0 + 67.5 = 73.5
Mixed air temperature will be 73.5 degrees F when the

OA is 60 degrees F and the RA is 75 degrees F with 10%

outdoor air.