Greenheck Fan ERV manual How does an energy recovery wheel work?

Model ERV

How does an energy recovery wheel work?

The basic objectives for providing acceptable indoor air quality (IAQ) are to control indoor contaminates levels while maintaining desired indoor air temperature and humidity. Compliance with the prescribed ventilation rates in ASHRAE Standard 62 appear to satisfy the contaminant issue. However, simply increasing outdoor air (OA) requirements with “traditional” HVAC systems may not address the humidity issue properly and often leads to significant energy cost increases.

45

80

40

75

35

The best solution for most commercial and institutional facilities

DRY

AIR

OF

will include an enthalpy wheel product. The enthalpy wheel

POUND

70

PER

30

Temp

-

°F

transfers temperature and moisture properties from one

BTU

Saturation

ENTHALPY

-

65

70

airstream to another. The result is capturing the cooling

Bulb,

heating energy before it leaves the HVAC system.

25

Wet

60

65

Moving through the unit, the return and supply

pass on opposite sides of a divider panel. The
enthalpy wheel rotates between the
transferring up to 75% of the energy
present in the exhaust airstream to				5
the supply.	0			10
		0		5
	-5			5
			0

15

10

12

. 0

10

20

15

			20
		15	45
			40
			35
	30		40
25			35
			30
20		25

50

55		90%
		80%
			60
		70%	55
		60%
	50	50%
45		40%
13
.		30%
0
		20%
			RELATIVE	HUMIDITY
		10%

-10	-5	0	5	10	15	20	25	30	35	40	45	50	55	60	65	70	75	80
Chart by: HANDS DOWN SOFTWARE, www.handsdownsoftware.com													DRY BULB TEMPERATURE - °F

0.20	0.25	0.30	0.35		0.40
	SENSIBLE HEAT RATIO = Qs / Qt
50		55
						1.15
				170	0.45
						1.10
	85
				160		1.05
					80
			15	150	0.50	1.00
			.
			0
						0.95
				140

	80
	WET	BULB
			TEMPERATURE-
75
			°F
14
.
0
VOLUME
-
CU	25%
.
.
FT
PER
LB
.
DRY
AIR
	15%
			HUMIDITY
		RELATIVE
		8%
		6%

HUMIDITY RATIO - GRAINS OF MOISTURE PER POUND OF DRY AIR

			0.55	0.90
	75
130
				0.85
120			0.60	0.80
110	70		0.65	0.75
		- °F
				0.70
		TEMPERATURE
100			0.70
				0.65
90	65		0.75
				0.60
80		POINT	0.80
			0.85	0.55
	60	DEW
			0.90	0.50
70			0.95
				0.45
	55		1.00
60			/ Qt	0.40
	50		= Qs	0.35
50			RATIO
	45		HEAT	0.30
40
	40		SENSIBLE	0.25
30	35			0.20
	30			0.15
20
	25
	20			0.10

		4%					10	10
									0.05
		2%						0
85	90	95	100	105	110	115		120

VAPOR PRESSURE - INCHES OF MERCURY

55

50

45

40

35

ENTHALPY - BTU PER POUND OF DRY AIR

0 5 10 15 20 25 30

	Enthalpy Wheel
Supply Air to Building		Filters		Outdoor Air Weatherhood
Supply					Outdoor Air
Blower
			Exhaust Blower
Return Air From Building	Filters
				Exhaust Weatherhood

Exhaust Air

Certifications

Utilizing an enthalpy wheel to precondition the outdoor air, narrows the operational range of outdoor air conditions which the building’s HVAC equipment is designed to temper. It is this reduction in the outdoor air range that allows for size reduction in heating and cooling equipment and reduced energy costs.

ERV’s construction is matched with extensive in-house testing and third-party verification of performance and safety.

Licensed to bear the AMCA seal for

Air Performance

Unit is ETL Listed — all internal electrical components are factory wired to a single-point power connection

ARI Standard 1060 certified energy wheel performance assures the ERV model will function as required in demanding environments

Greenheck certifies that the ERV models shown herein are licensed to bear the AMCA seal. The ratings shown are based on tests and procedures performed in accordance with AMCA Publication 211 and comply with the requirements of the AMCA Certified Ratings Program.

Every unit is tested at the factory before it is shipped to the job site.

Energy recovery wheels are certified by the ARI Air-to-Air Energy Recovery Ventilation Equipment Certification Program in accordance with ARI Standard 1060. Actual performance in packaged equipment may vary. Certified ratings are available in the Certified Product Directory at http://www.ahridirectory.org/ahridirectory/pages/home. aspx

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