4. NGAT Study Results

The general purpose of the NGAT Study was to obtain information that would allow the development of uniform LIEE program standards, policies and procedures regarding combustion appliance testing. The following research questions were addressed by the NGAT study:

1. In low-income homes in California, what are the pre-existing levels of CO in the following locations: a) in indoor ambient air, b) in the proximity of specific appliances, c) in flue gases, and d) in the surrounding outdoor air?

2. What effect does the installation of infiltration-reduction measures have on CO levels within the home?

3. Do pre-existing or post-installation CO levels found in low-income homes represent a potential hazard to the occupants? What is the frequency and duration of elevated CO levels?

4. Are the existing policies and procedures and Minimum Standard for natural gas appliance testing previously recommended by the Team and adopted on an interim basis by the Commission necessary, and, if so, are they appropriate to identify high levels of CO and other combustion-related hazards in the homes of LIEE weatherization recipients?

5. To what extent would the detection of CO problems be affected by the elimination, reduction, expansion or modification of steps included in the Minimum Standard (including the installation of CO alarms as an alternative or supplement to gas appliance testing)?

6. What modifications, if any, to the current natural gas appliance CO testing policies and procedures should be adopted for the LIEE Program?

Briefly, the study approach involved: (1) a review of the literature on CO levels and impacts, (2) a survey of private contractor practices relating to combustion appliance testing, (3) analysis of data on CO testing under the PG&E LIEE program, (4) an extensive on-site survey of low-income homes, including extensive CO testing, (5) blower-door tests of infiltration reduction in a sub-sample of these homes and (6) an assessment of the performance of CO alarms in a sub-sample of these homes. Each of these study elements is described in considerable detail in the May 5, 2003 final NGAT report.

In the following sections we summarize the Team's findings and recommendations, based on the study results.

4.1. CO Effects on Health and Related Issues

As a context for addressing the research questions listed above, the Team conducted an extensive literature review with respect to CO and its effects on health, CO levels found in residential buildings, linkages between infiltration rates and CO concentrations and related issues. In this section, we briefly present a summary of the study findings from the literature research, and refer the interested reader to Section 3 and Appendix E of the final NGAT report for additional detail. ²⁵

As the Team explains in the report, several studies indicate that prolonged exposure to high levels of CO can have dire consequences on human health. CO's affinity to bind with blood hemoglobin is 200 times higher than that of oxygen. CO poisoning occurs when high levels of CO combine with hemoglobin in the blood to form COHb, thereby impeding the flow of oxygen in the body. In general, as blood COHb levels become higher and higher, the symptoms of CO poisoning become more and more severe. Blood COHb levels vary as a function of time and level of exposure, respiratory rate, age of the patient, and presence of underlying illness. Initial symptoms of CO poisoning include headache, fatigue, shortness of breath, nausea, and dizziness. Extended exposure to high levels of CO leads to cardiovascular and neurological symptoms and can eventually result in unconsciousness and death.

Analyses of unintentional deaths due to CO exposure have shown that between 1979 and 1993, the number of unintentional CO-related deaths fell in real numbers and as a percentage of all CO-related deaths. Furthermore, CO poisoning appears to be predominantly a cold weather phenomenon. Death rates in California are low relative to national rates. The number of unintentional CO-related deaths in California during the ten-year period from 1979-1988 period totaled 444, based on data from a 1993 study.²⁶

California data show that 39% of unintentional CO-related deaths had combustion appliances as a source, or a total of 177 deaths over the 1979-1988 period.²⁷ California data also show that CO levels tend to be higher in multi-family dwellings and temporary shelters than in single family homes. Additionally, bottled tank and liquefied petroleum gas-fueled appliances exhibit a greater tendency to CO problems than natural gas-fired appliances.

CO exposure problems associated with combustion appliances stem from the "spillage" of combustion byproducts into the room. Spillage is usually caused by inadequate drafting, i.e., an insufficient amount of force to pull byproducts through the appliance vent or exhaust. In addition, spillage can be caused by negative pressure in a room, caused by an exhaust fan. For example, the range hood exhaust fan in a kitchen can cause spillage from a water heater in the same room, under certain circumstances. Finally, blockage or obstruction in a vent (e.g., a bird's nest) can cause spillage.

The Team considered previous evidence on the potential impacts of infiltration reduction on ambient CO levels. On a theoretical level, the overall impact of infiltration reduction on ambient CO may depend on three factors. First, infiltration reduction measures may significantly reduce air exchange rates and lessen the escape of CO to the outside. As joints, cracks in walls, floors and ceilings and around windows and doors become sealed, the rate at which outdoor air replaces indoor air is lowered (i.e., infiltration rates are lowered). To the extent that significant internal sources of CO are present, ambient CO levels may increase because of the reduced flow of air through the home and the associated escape of the CO to the outside.

Second, infiltration reduction and other weatherization measures may significantly reduce the amount of heating needed. If heating systems are responsible for CO concentrations, these CO emissions from heating appliances should also decrease when less heating is needed. If most pollutants inside the home are by-products of heating appliances, then the emission of these pollutants may remain constant or actually decrease with the installation of these measures.

Third, apart from the low air exchange rates mentioned above, another infiltration-related problem is that air exhaust systems can remove too much air from the house, thus creating a slight negative pressure inside the house. When too much air is removed, the negative pressure can become large enough to reverse the natural flow of gases up the furnace flue and instead cause the flue to become a passageway for the supply of outside air into the house. If the furnace burner is operating at that time, its products will not escape through the flue, but will instead enter the house, causing spillage problems. However, the relationship between negative pressure inside the house and infiltration reduction measures also is not clear. This is because one cause of negative pressure (referred to as the "stack effect") can actually be reduced using infiltration reduction measures, while a second cause of negative air through exhaust devices can be exacerbated with the installation of infiltration reduction measures.²⁸

On a priori grounds, then, it is not clear if infiltration reduction measures would actually increase or decrease the levels of CO found inside the home. The Team found that the empirical studies to date do not offer strong evidence of a relationship between infiltration reduction and ambient CO. According to one study, infiltration is not reduced to the levels required for new energy efficient construction, and the California Energy Commission has found that these new construction standards cause no internal air quality problems. However, the Team was not able to locate research on the incidence of backdraft conditions in California homes.

4.2. Standards on Threshold Levels of CO

There are various locations in the vicinity of a household appliance where CO levels can be tested. Ambient CO levels can be measured in the middle of a room (generally referred to as a "room ambient test") or close to a particular appliance ("appliance ambient test"), such as a water heater. In addition, CO levels can be measured within the appliance itself at a point before room air mixes with combustion byproducts. This type of test is referred to as a "flue" or "exhaust" test, depending on the appliance.²⁹

As the Team reported during earlier phases of the Standardization Project, there are no U.S agency standards for CO levels in indoor residential environments. However, varieties of organizations do have published standards for ambient CO in other environments (outdoor and industrial), which are summarized in the final NGAT report. The standards are generally set to protect the safety of individuals with relatively high susceptibility to CO, and also vary across applications and jurisdictions. The Commission considered these standards in developing threshold CO levels as a component of the Minimum Standard for gas appliance testing in D.01-12-020.³⁰ For the purpose of evaluating the CO levels detected in the NGAT study, the Team utilized the Commission-adopted thresholds, as follows:

· An ambient threshold of 10 ppm as an action level, or a level that should prompt more extensive investigation and analysis of the source of CO.

· An ambient level of 35 ppm as a threshold level at which the home should be ventilated, the occupants should be advised to evacuate, and the technician should restrict exposure to 15 minutes. In these cases, the offending appliance is made inoperable pending repair or replacement.

The American National Standards Institute (ANSI) also publishes standards for flue CO levels that the utilities use (along with standards they have developed over the years) to test to see if an appliance is operating properly. The Team considered these standards as they conducted the CO tests described below.

4.3. Pre-Weatherization CO Levels and Sources

The NGAT study examined pre-weatherization ambient CO levels for a sample of 786 LIEE-eligible homes. For this purpose, ambient CO was measured under a variety of conditions with respect to appliance operation, exhaust fan operation and window and door positions, and ambient readings were taken with two different instruments.

Table 2 summarizes the results of the distribution of the maximum of all readings. The last column summarizes the distribution of the maximum of all readings. This is based upon the highest reading from all ambient tests, regardless of the room and the type of test.

Table 2: Distribution of Highest Net Reads for CO Ambient Tests

CO Read in PPM	Test #1 Room Ambient	Test #2 Room Ambient	Appliance Ambient	Maximum Across All Tests
Percent with Ambient CO at or above the action level of 10 ppm	0.16%	6.30%	3.22%	7.1%
90% confidence interval on Percent with Ambient CO at or above the action level of 10 ppm	-0.07% to 0.39%	4.87% to 7.73%	2.15% to 4.29%	5.59% to 8.61%
Percent with Ambient CO at or above The threshold level of 35 ppm	0.00%	0.33%	0.19%	0.50%
90% confidence interval on Percent with Ambient CO at or above the threshold level of 35 ppm		0.00% to 0.66%	0.03% to 0.35%	0.09% to 0.91%
Arithmetic Average CO (ppm)	0.38	3.239	1.90	3.51
90% confidence interval on arithmetic average CO (ppm)	0.31 to 0.46	2.89 to 3.59	1.69 to 2.11	3.14 to 3.87
Geometric Average CO (ppm)	0.08	0.83	0.39	0.96
90% confidence interval on geometric average CO (ppm)	0.07 to 0.09	0.73 to 0.94	0.34 to 0.45	0.85 to 1.08
Number of Homes w CO Reads	786	785	730	786

Based on these results, the Team reached two conclusions:

· In a population of 1000 homes, 71 (on average) would have at least one ambient reading at or above 10 ppm and would require further investigation of CO sources in the home. There were 55 such homes in the statewide NGAT sample.

· In a population of 1,000 homes, five homes (on average) would have an ambient reading of 35 ppm or greater. At this threshold, the home should be ventilated, the occupants should be advised to evacuate, and the technician should restrict exposure to 15 minutes. In these cases, the offending appliance should be made inoperable pending repair or replacement. There were four such homes in the statewide NGAT sample.

The Team also assessed the sources of preexisting ambient air CO levels, based on the NGAT sample. They found that the two rooms that were most likely to have room ambient CO levels at or above 10 ppm were kitchens and living rooms. The data also suggests that the most cases of "action level" (greater than 10 ppm) ambient CO levels were associated with kitchen appliances.

In addition, appliance exhaust/flue CO tests were conducted as part of the survey in order to test the role of such tests in detecting potentially hazardous levels of CO. At present, only PG&E conducts these tests as a standard procedure, in lieu of ambient CO tests. The other natural gas utilities (SDG&E and SoCalGas) conduct room ambient CO testing and use a variety of diagnostic approaches (including flue testing for specific appliances, depending on the circumstances) to determine the cause of CO readings at or above the 10 ppm action level. The flue/exhaust tests taken during the NGAT study were conducted under default worse case conditions in terms of home ventilation and appliance operations, and at various flue/exhaust pipe locations. As discussed in the report, the flue/exhaust CO levels vary widely across appliances and homes, and tend to exceed standards most frequently for ovens and broilers.

4.4. Impact of Infiltration Reduction Measures on Ambient CO Levels

Currently, only PG&E requires testing of CO levels both before and after the installation of LIEE infiltration-reduction measures (caulking, door weatherstripping, attic access weatherstripping, evaporative cooler covers and outlet gaskets ). The other utilities test CO levels after measure installation. One of the key research questions addressed in the NGAT study was the potential impact of infiltration reduction on ambient CO levels.

Accordingly, the Team analyzed changes in ambient household CO levels from the pre-weatherization period to the post-weatherization period. These changes were measured with appliances off (Room Ambient Test #1) and with appliances on and the home in a "typical" condition (Room Ambient Test #2). Tables 3 and 4 present the results of these two tests.

Table 3: Changes in Room Ambient Test #1

	Change in Average Reading		Change in Maximum Reading
Change in CO in ppm	Unweighted Household Numbers	Weighted Household Percentage	Change in CO in ppm	Unweighted Household Numbers
<-5	6	0.76%	7	0.87%
-5	1	0.11%	4	0.43%
-4	7	0.82%	8	1.00%
-3	24	3.00%	25	3.30%
-2	48	6.37%	56	7.21%
-1	67	8.82%	60	7.85%
0	552	69.56%	550	69.48%
1	55	7.27%	41	5.43%
2	16	1.97%	19	2.41%
3	5	0.60%	8	0.99%
4	2	0.28%	4	0.50%
5	0	0.00%	0	0.00%
> 5	3	0.43%	4	0.54%
Average Change	-0.21	-0.21	-0.21	-0.21
% with Positive Change	10.68%	10.89%	9.44%	9.58%
% with Negative Change	21.99%	23.06%	22.24%	23.11%
Average Positive Change	1.46	1.45	2.07	2.10
Average Negative Change	-1.82	-1.79	-2.03	-2.02
Total Number of Homes	786	786	786	786

Table 4: Changes in Room Ambient Test #2

	Change in Average Reading		Change in Maximum Reading
Change in CO in ppm	Unweighted Household Numbers	Weighted Household Percentage	Unweighted Household Numbers	Weighted Household Percentage
<-5	15	1.79%	29	1.81%
-5	16	2.03%	21	37.94%
-4	37	4.69%	36	7.02%
-3	48	5.82%	66	9.29%
-2	81	10.46%	71	9.37%
-1	114	14.94%	86	8.96%
0	325	41.60%	318	5.89%
1	80	9.79%	71	4.51%
2	36	4.55%	42	3.09%
3	13	1.65%	17	3.75%
4	5	0.59%	12	1.83%
5	4	0.61%	2	5.36%
> 5	11	1.48%	14	0.99%
Average Change	-0.53	-0.50	-0.67	-0.64
% with Positive Change	19.75%	19.46%	19.63%	19.24%
% with Negative Change	42.36%	42.81%	40.87%	41.30%
Average Positive Change	1.98	2.04	2.54	2.64
Average Negative Change	-2.27	-2.216	-3.01	-2.95
Total Number of Homes	785	785	785	785

As indicated above, no significant change in ambient CO was found for homes receiving infiltration-reduction measures on average. In fact, the data indicates that CO levels fell very slightly on average between the pre- and post-weatherization periods for homes tested under this statewide survey.³¹ Observed positive changes in CO levels were lower in magnitude (on average) than observed negative changes, and were relatively low in absolute terms (2 ppm or less). In addition, the Team conducted blower door tests on a sample of homes both pre- and post-weatherization in order to more directly examine the relationship between changes in infiltration and changes in CO. This examination also did not reveal any systematic relationship between infiltration-reduction measures and CO levels, i.e., that such measures caused an increase in CO levels.

In addition, the Team examined the effect of infiltration-reduction measures on drafting. Of the 1,110 pre-weatherization and post-weatherization spillage tests conducted, there were only two instances (.018% of all spillage tests) in which the appliance "passed" the draft tests during the pre-weatherization survey and "failed" during the post-weatherization survey. The reason for the draft test fails could not be conclusively isolated to the installation of infiltration measures, in either instance.

In sum, the study reveals no clear evidence that weatherizing LIEE program homes significantly impacts the overall level of room ambient CO, or significantly affects appliance drafting. However, the Team presents two caveats to these results. First, the Team suggests that confounding factors like the influence of dust buildup in seldom-used appliances may have affected the results. Second, the Team believes that it is possible that the effect of building infiltration reduction on ambient CO levels may take a considerable amount of time to take effect and may be missed by spot tests, such as the ones used in the study.

4.5. Adequacy of Minimum NGAT Standard

The current minimum NGAT standard (Standard) is presented in Attachment 3. Based on the identification of the sources of CO level problems in each home, the Team assessed the adequacy of the Standard to detect pre-weatherization ambient CO levels above the action level. The Team points out the following about this Standard:

· The Standard entails a series of visual examinations focusing on flue/vent systems and appliance components. These elements of the Standard are most relevant to space heating and water heating, although at least some utilities may do other checks not included in the Standard on other appliances.

· The Standard includes indoor ambient CO tests similar to those used in the NGAT survey. However, the Minimum Standard Room Ambient Test 2 is conducted with only the space heating system in operation, whereas this test was conducted with all combustion appliances operating under the NGAT protocols. Further the Standard Room Ambient Test 2 is conducted in the middle of the living space away from registers and appliances, whereas this test was conducted in several rooms under the NGAT protocols.

· The Standard includes tactile and smoke draft tests, but not an instrument test.

In most of the homes with ambient CO levels at or above the action level (10 ppm), the cause of the CO appeared to be a kitchen appliance, generally an oven. The Team also found that that ambient CO levels above the threshold of 35 ppm were traceable to kitchen appliances in two homes.

The Standard identified all seven of the homes for which space heating appliances appeared to be responsible for CO at or above the 10 ppm action level. However, the Standard only detected CO problems in one of the 47 homes at or above the action threshold for which kitchen appliances were responsible. In the Team's view, this is because the Standard is not specifically designed to assess the performance of kitchen appliances. Problems in the remaining 46 homes would have been detected if the Standard required a room ambient test in the kitchen while kitchen appliances were operating, as well as visual inspections of kitchen appliance burners/pilots. Kitchen appliance exhaust/flue tests would also have revealed the CO problems. However, these tests would also have failed 124 homes with ambient CO levels below 10 ppm.

The Team also found that the current Standard did not provide sufficient information to identify all of the three water heaters responsible for ambient CO readings at or above 10 ppm for the survey sample. The testing also revealed that over 5% of water heaters had inadequate draft. Under the current Standard, room ambient tests are taken with the water heating appliance off. If these tests were taken with water heating appliances operating, the three homes with CO levels exceeding the 10 ppm threshold (as well as one home that exceeded the 35 ppm threshold) would have been identified. A water heater flue test or appliance ambient test would also have detected problems in the remaining homes. However, the flue test would also have failed 24 homes with ambient CO levels below 10 ppm.

The Team also assessed the application of the Standard to gas logs and combustion dryers. Only 26 homes had gas logs, and only one of these homes was found to have ambient CO levels above the action level. Because the Standard does not explicitly apply to gas logs, it did not discern this one case. The NGAT survey gave no evidence of any ambient CO associated with combustion dryers, and none of these appliances exceeded standards for as-measured flue CO.

4.6. Relationship Between Flue Tests and Ambient CO Levels

The Team concludes from the results of the NGAT survey that the relationship between exhaust flue CO levels and room ambient CO levels is relatively weak. In other words, detections of CO levels above standards for appliance flue/exhaust tests do not systematically translate to ambient air CO levels that exceed safety standards. Nonetheless, the Team postulates that exhaust/flue CO could present a problem if there is inadequate draft, and that this may not show up in ambient tests under certain weather conditions. As the Team explains:

"...[T]he instrument draft test is designed to indicate whether or not appliance draft problems could occur under more adverse weather conditions than experienced at the time of the survey tests. Combustion appliance drafting tends to be somewhat minimized in warmer weather, so readings taken on relatively warm days (like those experienced during most of the survey period) may not be accurate indicators of appliance draft performance under winter conditions. One question to be addressed by this study is the adequacy of a less rigorous testing (i.e., the tactile test and the smoke test) to detect the potential draft problems that could be revealed by instrumented draft tests."³²

The Team proceeded to evaluate the accuracy of the draft test options, and found that the smoke tests give virtually identical results to those yielded by instruments, at significantly less cost.

4.7. CO Alarm Study

The primary goal of the CO Alarm study was to evaluate whether CO alarms could be used as an alternate or supplement to combustion appliance testing in weatherized homes. To determine this, CO alarms were installed, studied and monitored in 100 of the homes included in the NGAT study. The Team found that ten percent of alarms failed the tests conducted to determine their sensitivity to a specific level of CO, based on ANSI standards, and that the nuisance rate of the alarms was relatively high (15%).

4.8. Team Recommendations

The Team first considered the threshold issue of whether the levels of CO found in the NGAT survey homes were high enough to warrant conducting any tests for CO or CO-related problems as part of the LIEE program. The Team found that addressing this question is complicated by two issues:

_ First, there is considerable disagreement about the level at which CO presents a potential hazard. Health effects depend partly on the characteristics of the parties subject to exposure. Moreover, the relationship between health effects and CO levels is more or less continuous, and characterizing a specific level at which CO becomes hazardous is an inherently judgmental process.

_ Second, the results discussed in this section do not directly deal with the issue of duration of CO exposure and the cumulative effects of multiple exposures during a 24-hour period. Both are strong determinants of health effects. This issue cannot be addressed as rigorously as would be desirable because of the necessity of relying on short-term readings in the NGAT survey. The study considered the sources of high CO and concluded that many of the high readings were associated with kitchen appliances. Unfortunately, the nature of the data collected in this survey makes it difficult to generalize with any certainty about the duration of high CO levels and the potential of multiple episodes during a 24-hour period.

In consideration of these and other issues, the Team recommends that CO testing continue under the LIEE Program. The Team makes several recommendations to further standardize these testing procedures, based on the results of the NGAT survey. These recommendations are discussed below and summarized in Attachment 4.

4.8.1. CO Testing Procedures

Based on the study results, the Team recommends that CO testing take place only on a post-installation basis, for all utilities. This represents a fundamental change for PG&E, which has been routinely testing CO levels both pre- and post-installation for many years.

In addition, the Team recommends specific changes and additions to the NGAT testing procedures. In particular, the Team recommends that room ambient CO tests be conducted for rooms with water heaters and kitchen appliances (cook top, over/broiler), with these appliances turned on. In addition, the Team recommends that gas logs be tested for CO levels in the form of an exhaust test. Smoke draft tests would now become a required procedure for space heaters, natural draft water heaters and gas logs. The Team also recommends adding visual examination procedures for cooking appliances, gas logs and clothes dryers. Attachment 4 presents a summary of the Team's recommended NGAT testing procedures, as compared with the current Minimum Standard.

The Team recommends against the use of CO alarms as either a substitute for or a supplement to the testing procedures, based on the high failure rate during the sensitivity tests, the number of nuisance alarms and information gathered during the literature review.

With respect to flue tests, the Team recommends that the utilities retain discretion over whether to conduct these tests for heating appliances and water heaters. The Team's recommendation on this issue reflects a fundamental disagreement among Team members concerning the relevance of flue CO levels. Some members believe that the flue CO, in itself, is not relevant to health and safety insofar as it is normally contained in the flue and does not affect the air the customer breathes. Others believe that flue CO should be assessed even in the absence of high ambient CO levels because it could constitute a potential future problem should drafting become impaired. As a result, the final report presents an "either or" option with respect to this issue. That is, the utility may either conduct indoor ambient CO tests with water and space heating appliances operating or flue CO tests of the individual appliances, at the utility's discretion. Kitchen appliances do not have flues, and therefore the Team recommends ambient CO tests (with the probe located within 24 inches of the appliance) in combination with visual and draft tests for these appliances. (See Attachment 4.)

4.8.2. Actions When Appliances Fail Test(s)

The Team also addressed the issue of what actions to take when appliances are found to have problems, and recommends the following:

_ In owner-occupied homes, natural gas space heaters failing one or more of the tests covered by the new protocol should be repaired or replaced.

_ In owner-occupied homes, natural gas water heaters failing one or more of the tests should be repaired or replaced.

_ In owner-occupied homes, natural gas appliances other than water heaters or space heaters (e.g., gas oven) failing one or more of the tests covered under the new protocol should be serviced.³³ If these repairs do not correct the problem in question, the appliances in question should be capped and reported to the owner.

_ In renter-occupied homes, appliances failing one or more of the tests covered by the new protocol should be serviced. If servicing an appliance does not correct the problem in question, the appliance be should be tagged, shut off, capped and reported to the tenant and the landlord.

As the Team points out, this approach would expand the types of appliances repaired or replaced under the program to include water heaters that are found to have CO-related problems. The Team estimates that the cost to expand repairs and replacements to cover water heaters would be approximately $1.9 million in 2003 for the three natural gas utilities (PG&E, SoCalGas and SDG&E).

4.8.3. Application of NGAT to Non-IOU Fueled Combustion Appliances and Related Issues

The Team also addresses two issues related to the applicability of NGAT procedures to combustion appliances that do not use investor-owned utility (IOU) natural gas, such as propane, kerosene or wood. The first issue relates to the issue of program eligibility based on which services a customer takes from the IOU. By way of background, it is important to note that customers who take service for space heating (either electric or natural gas) from the IOU are currently eligible for both LIEE infiltration-reduction measures (e.g., weatherstripping and caulking) and non-infiltration reduction measures (e.g., high efficiency refrigerator and room air conditioner replacements, evaporative coolers). Customers who do not take service from an IOU for either space heating or air-conditioning are not eligible for any LIEE measures. For homes that take air-conditioning services (but not space heating) from the IOU, the utilities have been authorized to offer heating, ventilating and air-conditioning LIEE measures, but not infiltration-reduction measures.³⁴ As discussed in D.01-12-020, we did not authorize infiltration-reduction measures for these homes because doing so "would require the IOUs to assume responsibility for implementing safety testing and repairs on a broad range of heating equipment that is not within their expertise, for which standards have not been established under the LIEE program, and for which funding has not been authorized in rates."³⁵ However, we directed the IOUs to refer these customers to other available assistance programs for weatherization services. We also stated that we might revisit this issue after we completed Phase 4 of the Standardization Project.³⁶

The Team addresses this issue in the Phase 4 report by generally endorsing the policy established in D.01-12-020, adding a refinement to address the implications of expanding CO tests to appliances other than space heating. As discussed above, the current Minimum Standard requires that only space heaters/furnaces be operating under the room ambient CO tests. The Team's recommendation that water heaters and kitchen appliances also operate during these tests raise the following questions: (1) Should the utilities conduct CO tests in the home if it has combustion appliances that do not utilize IOU natural gas? and (2) If the answer to question (1) is "no," should these homes be eligible for infiltration-reduction measures from the IOU?

The Team recommends that both questions be answered "no." Under the Team's proposed approach, utilities would not conduct CO testing procedures on homes that use IOU fuels for space heating but use non-IOU combustion fuels for one or more other end uses. Infiltration-reduction measures would automatically be deemed "non-feasible" in these homes, and would not be provided. However, the utilities would install non-infiltration reduction measures in these homes. The Team recommends that homes for which infiltration reduction measures are deemed non-feasible under this approach be referred to the Low Income Home Energy Assistance Program (LIHEAP), or, in the case of homes with non-IOU natural gas appliances, the relevant natural gas utility for full treatment. The Team also proposes that LIHEAP contractors and non-IOU natural gas utilities report back to the involved IOU to verify that service was provided. Attachment 6 provides an overview of current policy and the Team's recommendation with respect to non-IOU fuel use.

A second issue relating to the application of combustion appliance testing is the treatment of homes scheduled to receive only electric measures. As part of rapid deployment, utilities are permitted to go back to homes that have already been weatherized in order to install additional electric measures such as energy efficient replacement refrigerators. The Team recommends that natural gas appliance testing not be required in such cases where weatherization is not provided.