Outdoor Enthalpy Changeover

For enthalpy control, accessory enthalpy sensor (part number HH57AC078) is required. Replace the standard outdoor dry bulb temperature sensor with the accessory enthalpy sensor in the same mounting location. (See Fig. 21.) When the outdoor air enthalpy rises above the outdoor enthalpy changeover set point, the outdoor-air damper moves to its minimum position. The outdoor enthalpy changeover set point is set with the outdoor enthalpy set point potentiometer on the EconoMi$er IV controller. The set points are A, B, C, and D. (See Fig. 36.) The factory-installed 620-ohm jumper must be in place across terminals SR and SR+ on the EconoMi$er IV controller. (See Fig. 21 and 37.)

Differential Enthalphy Control

For differential enthalpy control, the EconoMi$er IV controller uses two enthalpy sensors (HH57AC078 and CRENTDIF004A00), one in the outside air and one in the return air duct. The EconoMi$er IV controller compares the outdoor air enthalpy to the return air enthalpy to determine EconoMi$er IV use. The controller selects the lower enthalpy air (return or outdoor) for cooling. For example, when the outdoor air has a lower enthalpy than the return air, the EconoMi$er IV opens to bring in outdoor air for free cooling.

(cfm)	2500
MINUTE	2000
	2000

PER	1500
	1500

FEET	1000
	1000

IN CUBIC	500
	500
	0
FLOW	0			0.05			0.15			0.25
				0.05			0.15			0.25
					STATIC PRESSURE (in. wg)
					STATIC PRESSURE (in. wg)
			Fig. 28 ---Barometric Flow Capacity								C06030
			Fig. 28 ---Barometric Flow Capacity
(cfm)	30
MINUTE	30
MINUTE	25
	25
PER	20
	20
	15
FEET	15
	10

CUBICIN
CUBICIN	0
	5
FLOW	0.13			0.20	0.22	0.25	0.30	0.35	0.40	0.45	0.50
FLOW					STATIC PRESSURE (in. wg)
											C06031
		Fig. 29 Outdoor-Air Damper Leakage---

(cfm)	6000
MINUTE	5000
	5000
PER	4000
	4000
	3000
FEET	3000
FEET	2000
CUBIC	2000
	1000
	1000
IN
FLOW	0
	0
	0.05	0.10	0.15	0.20	0.25	0.30	0.35
	0.05	0.10	0.15	0.20	0.25	0.30	0.35

STATIC PRESSURE (in. wg)

C06032

Fig. 30 ---Return-Air Pressure Drop

HH57AC078 ENTHALPY			551B,C
SENSOR	C7400A1004
	C7400A1004	+
		+

MOUNTING PLATE

C06361

Fig. 31 ---Enthalpy Sensor and Mounting Plate

SUPPLY AIR

TEMPERATURE

SENSOR

MOUNTING

LOCATION

SUPPLY AIR

TEMPERATURE

SENSOR

C06033

Fig. 32 ---Supply Air Sensor Location

551C, 551B specifications

The Bryant 551B and 551C are two highly efficient air conditioning units designed to provide optimal comfort in residential settings. Known for their reliability and performance, these models are part of Bryant's esteemed line of heating and cooling solutions.

One of the standout features of the Bryant 551B is its two-stage cooling system, which allows for better humidity control and increased comfort. This ensures that homeowners can enjoy consistent temperatures while reducing energy consumption. The unit operates quietly, thanks to its noise-reducing technology, making it an ideal choice for bedrooms and living spaces.

On the other hand, the Bryant 551C builds upon this foundation with its variable-speed compressor. This technology allows the unit to adjust its cooling output according to the specific needs of the home. This results in seamless operation and even greater energy efficiency. Both models also incorporate Bryant's advanced control capabilities, which allow users to monitor and adjust settings remotely via smart devices, adding a layer of convenience and modernity to home climate control.

With an emphasis on durability, both the 551B and 551C feature a galvanized steel cabinet that protects against weather-related damage. The powder coat finish further enhances their resistance to rust and corrosion, ensuring a long lifespan and minimal maintenance.

Another significant characteristic of these units is their excellent Seasonal Energy Efficiency Ratio (SEER) ratings. The 551B boasts a SEER rating of up to 16, while the 551C takes it even further with ratings exceeding 20. This efficiency not only translates to lower energy bills for homeowners but also contributes to a reduced carbon footprint, making these units environmentally friendly options.

Both models are also designed to operate with eco-friendly refrigerants, aligning with modern energy standards and regulations aimed at reducing greenhouse gas emissions.

In summary, the Bryant 551B and 551C are exemplary choices for homeowners looking for reliable, efficient, and high-performing air conditioning solutions. With features such as two-stage and variable-speed compressors, advanced smart technology, and robust construction, these models stand out in the competitive HVAC market. They promise a comfortable indoor environment along with significant energy savings, making them a wise investment for the future.

Bryant 551C, 551B Outdoor Enthalpy Changeover, Differential Enthalphy Control

Models: 551C 551B