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WAC 51-11C-10143: Table C101.4.3.2—Economizer compliance options for mechanical alterations


Published: 2015

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WACs > Title 51 > Chapter 51-11C > Section 51-11C-10143











51-11C-10140    

51-11C-10150







Agency filings affecting this section







WAC 51-11C-10143









Table C101.4.3.2—Economizer compliance options for mechanical alterations.









Table C101.4.3.2 Economizer Compliance Options for Mechanical Alterations

  Option A
Option B
(alternate to A)

Option C
(alternate to A)

Option D
(alternate to A)


Unit Type Any alteration with new or replacement equipment Replacement unit of the same type with the same or smaller output capacity Replacement unit of the same type with a larger output capacity New equipment added to existing system or replacement unit of a different type

1. Packaged Units
Efficiency: min.1

Economizer: C403.4.12


Efficiency: min.1

Economizer:
C403.4.12, 3


Efficiency: min.1

Economizer: C403.4.12, 3


Efficiency: min.1

Economizer: C403.4.12, 4



2. Split Systems
Efficiency: min.1

Economizer: C403.4.12


Efficiency:  + 10/5%5

Economizer: Shall not decrease existing economizer capability

Only for new units
< 54,000 Btu/h replacing unit installed prior to 1991 (one of two):
Efficiency: + 10/5%5 Economizer: 50%6


Efficiency: min.1

Economizer: C403.4.12, 4



     
For units ˃ 54,000 Btu/h or any units installed after 1991:
Option A
 

3. Water Source Heat Pump
Efficiency: min.1

Economizer: C403.4.12


(two of three):
Efficiency:  + 10/5%5

Flow control valve7

Economizer: 50%6


(three of three):
Efficiency:  + 10/5%5

Flow control valve7

Economizer: 50%6 (except for certain pre-1991 systems8)

Efficiency: min.1

Economizer:
C403.4.12, 4 (except for certain pre-1991 systems8)


4. Hydronic Economizer using Air-Cooled Heat Rejection Equipment (Dry Cooler)
Efficiency: min.1

Economizer: 14332


Efficiency: + 10/5%5

Economizer: Shall not decrease existing economizer capacity
Option A
Efficiency: min.1

Economizer: C403.4.12, 4



5. Air-Handling Unit (including fan coil units) where the system has an air-cooled chiller
Efficiency: min.1

Economizer: C403.4.12

 
Economizer: Shall not decrease existing economizer capacity Option A (except for certain pre-1991 systems8)
Option A (except for certain pre-1991 systems8)
 


6. Air- Handling Unit (including fan coil units) and Water-cooled Process Equipment, where the system has a water-cooled chiller10

Efficiency: min.1

Economizer: C403.4.12

Economizer: Shall not decrease existing economizer capacity
Option A
(except for certain pre-1991 systems8 and certain 1991-2004 systems9)

Efficiency: min.1

Economizer:
C403.4.12, 4 (except for certain pre-1991 systems8 and certain 1991-2004 systems9)


7. Cooling Tower
Efficiency: min.1

Economizer: C403.4.12

No requirements Option A Option A

8. Air-Cooled Chiller
Efficiency: min.1

Economizer: C403.4.12


Efficiency:  + 5%11

Economizer: Shall not decrease existing economizer capacity
Efficiency (two of two): (1) + 10%12 and (2) multistage Economizer: Shall not decrease existing economizer capacity
Efficiency: min.1

Economizer: C403.4.12, 4



9. Water-
Cooled Chiller

Efficiency: min.1

Economizer: C403.4.12


Efficiency (one of two): (1) + 10%13 or (2) plate frame heat exchanger15

Economizer: Shall not decrease existing economizer capacity

Efficiency (two of two): (1) + 15%14 and (2) plate frame heat exchanger15

Economizer: Shall not decrease existing economizer capacity

Efficiency: min.1

Economizer: C403.4.12, 4



10. Boiler
Efficiency: min.1

Economizer: C403.4.12


Efficiency:  + 8%16

Economizer: Shall not decrease existing economizer capacity

Efficiency: + 8%16

Economizer: Shall not decrease existing economizer capacity

Efficiency: min.1

Economizer: C403.4.12, 4





1
Minimum equipment efficiency shall comply with Section C403.2.3 and Tables C403.2.3(1) through C403.2.3(9).

2
System and building shall comply with Section C403.4.1 (including both the individual unit size limits and the total building capacity limits on units without economizer). It is acceptable to comply using one of the exceptions to Section C403.4.1.

3
All equipment replaced in an existing building shall have air economizer complying with Sections C403.3.1 and C403.4.1 unless both the individual unit size and the total capacity of units without air economizer in the building is less than that allowed in Exception 1 to Section C403.3.1.

4
All separate new equipment added to an existing building shall have air economizer complying with Sections C403.3.1 and C403.4.1 unless both the individual unit size and the total capacity of units without air economizer in the building is less than that allowed in Exception 1 to Section C403.4.1.

5
Equipment shall have a capacity-weighted average cooling system efficiency:

a.
For units with a cooling capacity below 54,000 Btu/h, a minimum of 10% greater than the requirements in Tables C403.2.3(1) and C403.2.3(2) (1.10 x values in Tables C403.2.3(1) and C403.2.3(2)).

b.
For units with a cooling capacity of 54,000 Btu/h and greater, a minimum of 5% greater than the requirements in Tables C403.2.3(1) and C403.2.3(2) (1.05 x values in Tables C403.2.3(1) and C403.2.3(2)).

6
Minimum of 50% air economizer that is ducted in a fully enclosed path directly to every heat pump unit in each zone, except that ducts may terminate within 12 inches of the intake to an HVAC unit provided that they are physically fastened so that the outside air duct is directed into the unit intake. If this is an increase in the amount of outside air supplied to this unit, the outside air supply system shall be capable of providing this additional outside air and equipped with economizer control.

7
Have flow control valve to eliminate flow through the heat pumps that are not in operation with variable speed pumping control complying with Section C403.4.3 for that heat pump.

 
 
– When the total capacity of all units with flow control valves exceeds 15% of the total system capacity, a variable frequency drive shall be installed on the main loop pump.

 
 
– As an alternate to this requirement, have a capacity-weighted average cooling system efficiency that is 5% greater than the requirements in note 5 (i.e., a minimum of 15%/10% greater than the requirements in Tables C403.2.3(1) and C403.2.3(2) (1.15/1.10 x values in Tables C403.2.3(1) and C403.2.3(2)).

8
Systems installed prior to 1991 without fully utilized capacity are allowed to comply with Option B, provided that the individual unit cooling capacity does not exceed 90,000 Btu/h.

9
Economizer not required for systems installed with water economizer plate and frame heat exchanger complying with previous codes between 1991 and June 2013, provided that the total fan coil load does not exceed the existing or added capacity of the heat exchangers.

10
For water-cooled process equipment where the manufacturers' specifications require colder temperatures than available with waterside economizer, that portion of the load is exempt from the economizer requirements.

11
The air-cooled chiller shall have an IPLV efficiency that is a minimum of 5% greater than the IPLV requirements in Table C403.2.3(7) (1.05 x IPLV values in Table C403.2.3(7)).

12
The air-cooled chiller shall:

a.
Have an IPLV efficiency that is a minimum of 10% greater than the IPLV requirements in Table C403.2.3(7) (1.10 x IPLV values in Table C403.2.3(7)); and

b.
Be multistage with a minimum of two compressors.

13
The water-cooled chiller shall have an IPLV efficiency that is a minimum of 10% greater than the IPLV requirements in Table C403.2.3(7) (1.10 x IPLV values in Table C403.2.3(7)).

14
The water-cooled chiller shall have an IPLV efficiency that is a minimum of 15% greater than the IPLV requirements in Table C403.2.3(7), (1.15 x IPLV values in Table C403.2.3(7)).

15
Economizer cooling shall be provided by adding a plate-frame heat exchanger on the waterside with a capacity that is a minimum of 20% of the chiller capacity at standard AHRI rating conditions.

16
The replacement boiler shall have an efficiency that is a minimum of 8% higher than the value in Table C403.2.3(5) (1.08 x value in Table C403.2.3(5)), except for electric boilers.

[Statutory Authority: RCW 19.27A.025, 19.27A.045, and 19.27.074. WSR 13-20-120, § 51-11C-10143, filed 10/1/13, effective 11/1/13. Statutory Authority: RCW 19.27A.020, 19.27A.025 and chapters 19.27 and 34.05 RCW. WSR 13-04-056, § 51-11C-10143, filed 2/1/13, effective 7/1/13.]