8431 Murphy Drive 

Middleton, WI 53562 

Telephone: 608 836 4400 

Facsimile: 608 831 9279 

www.intertek-etlsemko.com 

Intertek Testing Services NA, Inc. 8431 Murphy Drive, Middleton, WI 53652 

13 October 2011 

Ms. Brenda Edwards 

U.S. Department of Energy, Building Technologies Program 

Mailstop EE–2J, 1000 Independence Avenue, SW. 

Washington, DC 20585–0121 

DHE–2011–STD– 0047@ee.doe.gov 

Subject: NOPR on Energy Conservation Standards for Direct Heating Equipment 

Docket No. EERE-2011-BT-STD-0047 

RIN 1904-AC56 

Dear Ms. Edwards: 

I am the chief engineer for Intertek Testing Services NA Inc in the Hearth Products area. Intertek has 

been involved in the testing and certification of efficiency of many products and appliances regulated 

under the Energy Policy and Conservation Act and 10 CRF Part 430 regulations. We support this 

process by providing accurate and comprehensive testing and certification services to industry to 

assure that compliance with DOE requirements is documented and reliable. As an independent thirdparty testing and certification agency we have no direct economic or specific business interest that 

would be affected by additional or revised regulations aside from the obvious issue of regulations that 

result in specific industries we serve becoming non-viable. 

Intertek also provides safety testing and certification services in accordance with standards specified 

in various codes and regulations. As a result of this activity we have gained considerable expertise in 

the test methods and technology involved in the gas burning appliance industry. Within this context, 

we wish to provide the DOE with some comment on this energy efficiency initiative together with a 

broader examination related to safety testing, market constraints, consumer choice and cost 

effectiveness. 

Issue 1. Given the lack of a statutory definition for ‘‘direct heating equipment,’’ whether DOE’s 

interpretation that decorative vented hearth products and vented gas log sets are types of 

direct heating equipment is reasonable. 

Intertek’s does not take a position whether the DOE’s interpretation that decorative vented 

hearth products and vented gas log sets are types of direct heating equipment is reasonable or 

not. We do wish to provide some technical information regarding this product class that the 

DOE may wish to consider.
Intertek Testing Services NA, Inc. 8431 Murphy Drive, Middleton, WI 53562

 Utilizing the proposed interpretation (the fact that the decorative products in question 

have a flame present and inevitably provide some amount of heat to the room where 

they are located) would seem to require a similar but unintended interpretation for gas 

clothes dryers or water heaters since they also have a flame present and some of the 

heat produced inevitably results in radiation and warming of air. Obviously, for all of 

these products the primary function is not to act as a DHE. 

 Based upon our evaluation of this product type, many decorative gas appliances are designed 

to provide as little heat as possible to the space in which they are installed. For example, 

decorative gas appliances are frequently installed in restaurants, bars and hotel lobbies where 

significant heat output is not desirable. A very significant portion of the market for decorative 

gas appliances is in climate zones where energy consumption for heating is minimal and 

cooling is by far the largest energy consumption application. Decorative gas appliances are 

often operated to provide a cosy or romantic ambiance even though the space may be airconditioned much of the time. In such cases the owner wants only the visual appeal, but 

certainly not high heating efficiency. In fact, a high heating efficiency would only increase 

energy consumption as it would increase the cooling load. 

 Alternatively, in some instances these devices are installed without an objective to prohibit or 

limit heat production. While these products are primarily for aesthetic appeal, some 

consumers also would choose to have heat production as a secondary or back-up heat source. 

Even if the heating efficiency is low compared to heater rated products, any heat output would 

be seen as a bonus to someone who anticipates using the appliance primarily during the 

heating season in a cold climate. Because of the mixed reasons for installing these products, 

it may prove difficult to correctly gauge what a consumer actually wants in terms of energy 

efficiency for this type of product. 

 Gas log sets that are designed to be installed in wood burning fireplaces produce a highly 

variable net heat output that cannot be readily evaluated as the heat production is a function of 

the particular fireplace and log set combination. In most cases the net heat output depends on 

the specific fireplace geometry, materials, chimney and damper, duration of operation and 

outdoor temperature. Because the heat output is so low, test measurement for efficiency 

purposes may not provide meaningful data. In any case, there is no currently recognized test 

method for evaluation of efficiency for this product type. 

 Decorative gas appliances are not allowed, under applicable codes and safety standards, to be 

supplied or installed to operate under thermostatic control. They are supplied with an ON/OFF 

control which may be a knob or valve on the appliance, a simple electrical switch or even a 

remote control. They are clearly not intended to turn on and off on their own in response to 

room temperature. They are intended to be turned on when the user wants to see the fire 

burning and off when he/she does not. Usage patterns are thus discretionary, highly variable 

and unpredictable. Some gas fireplaces may only be operated for a few hours a year, if at all, 

and others may be on continuously during business hours of a hospitality establishment. 

Heating appliances are designed and intended to maintain a comfortable room temperature 
Intertek Testing Services NA, Inc. 8431 Murphy Drive, Middleton, WI 53562

automatically through thermostatic control. DOE has correctly identified thermostatic control 

as a key distinguishing feature of heating appliances. This is already codified in the National 

Fuel Gas Code (NFPA 54-2009) as follows: 

“10.6.2 Installation. A decorative appliance for installation in a vented fireplace shall be installed only 

in a vented fireplace having a working chimney flue and constructed of noncombustible materials. These 

appliances shall not be thermostatically controlled.”

 (Emphasis added.) 

 Without thermostatic control and regular use, establishing average usage patterns for 

purposes of determining energy efficiency or costs, it may prove difficult to provide meaningful 

guidance to the consumer. 

 

 The usage pattern issue creates a substantial issue with application of the test method 

specified which applies to gas room heaters, and wall and floor furnaces. This test method (10 

CFR part 430, subpart B, appendix O) is built upon the basic premise that the appliance is 

installed and operated to satisfy a heating load of a building. Calculations and factors used to 

define Annual Fuel Utilization Efficiency (AFUE) are based on specific data such as indoor and 

outdoor design temperatures, heating degree days, heating and non-heating hours per year, 

and on and off cycle times. These are all factors that are irrelevant for appliances whose 

purpose is primarily decorative and not heating. There is a further concern in attempting to 

adapt the test method to approximate actual use where, almost certainly, these products will 

be used in an environment with functioning primary heating or cooling equipment. 

We have no comments on issues 2, 3 and 4 as listed in the NOPR. However, we do wish to provide 

some information concerning the specific proposal to eliminate the use of continuously burning 

standing pilot lights. We are concerned that elimination of standing pilot ignition systems may have 

important unintended consequences. 

 Standing pilot lights have been a very important safety feature of gas fired appliances that may 

not be readily replaced by intermittent or electronic ignition system alternatives. The most 

obvious is that they do not require a connection to household electrical power or batteries to 

operate. That means that they can be installed and operate safely even when no electrical 

power is available. In the case of long term winter power outages, a dual purpose decorative 

gas appliance with a secondary heating function can provide sufficient back up heating to 

mitigate serious risk to buildings and occupants. 

 Standing pilot light ignition systems can significantly reduce installation costs as, in many 

cases, they would make it unnecessary to hire an electrician to install a circuit that would be 

needed by most Intermittent Electric Ignition systems. Decorative gas log sets are virtually 

always installed in masonry or factory built wood burning fireplaces where an electrical 

connection is typically not available. Built-in decorative fireplaces generally require a hardwired electrical connection to operate an electronic ignition system. 
Intertek Testing Services NA, Inc. 8431 Murphy Drive, Middleton, WI 53562

 Consumers may be more likely to turn off the pilot light of a decorative appliance installed in a 

frequently used room where they can see the pilot than in direct heating equipment such as 

cabinet style room heaters or wall and floor furnaces where one would have to go to some 

effort to determine if the pilot light is on or not. Therefore, the assumption that 75% of users 

would not turn pilot lights off when the appliance is not being used regularly may be high. It 

seems that a notification advising consumers to turn off pilot lights during the non-heating 

season should mitigate the energy consumption concern below 75%, as is the assumption with 

other manually controlled DHE appliances. Certainly, for those consumers who value energy 

efficiency, use of a pilot light control to turn off the appliance allows direct control over the 

energy efficiency of the product. 

 Based upon our experience in testing these products the vast majority of pilot light controls 

consume less than 800 Btu/hr. Therefore, the estimate of 1250 Btu/hr as an average pilot 

light gas consumption is probably high. 

 Again, based upon our experience in testing these products, most gas log sets actually sold 

are “manually lit” and have no pilot light or IEI systems. The proposed elimination of standing 

pilots lights would, in our opinion, tend to discourage greater use of safer flame proving 

automatic ignition systems and result in more installations of manually lit gas log sets. In fact 

the proposal would eliminate from the market the lowest cost decorative appliances that have 

automatic ignition and flame failure safety controls. This would leave consumers who can’t 

afford the higher cost of IEI equipped products with only the low cost and potentially less safe 

manually lit appliances to choose from. 

 The DOE should consider the benefit of allowing designs to include standing pilot lights, 

particularly in decorative appliances with large glass fronts. In the event a gas valve fails to 

close completely when the main burner is shut off, a standing pilot will ignite the leaking gas as 

soon as the concentration reaches the “Lower Flammability Limit”. This results in an explosive 

ignition of relatively low energy and power. Under the same condition an IEI system will 

attempt ignition only when the control calls for it (whether this is automatic or the result of the 

user turning the appliance on). The timing can result in ignitions when the appliance is filled 

with a significantly higher concentration of gas and result in a substantially more powerful 

explosion with an increased potential to break the glass and possibly cause injury. 

 There are products that can be either an unvented room heater or a vented decorative 

appliance as indicated in the following from ANSI Z21.11.2: 

“1.21.15 

A heater having dual certification (ANSI Z21.11.2 & Z21.60) and which uses a common rating 

plate and printed instructions to indicate that the model can be used as both an unvented room 

heater and as a vented decorative appliance for installation in a solid-fuel burning fireplace or 

listed ventless firebox enclosure, shall have the following statement included in the printed 
Intertek Testing Services NA, Inc. 8431 Murphy Drive, Middleton, WI 53562

instructions: “State or local codes may only allow operation of this appliance in a vented 

configuration. Check your state or local codes.”” 

The proposed elimination of pilot lights would be problematic for this type of appliance as it 

must have an Oxygen Depletion Safety Shutoff system which is a specialized form of a 

standing pilot. When installed as an unvented room heater these appliances are, of course, 

nearly 100% efficient heaters, but when installed as vented decorative appliances in a fireplace 

the efficiency is unknown, but certainly substantially lower. 

While we understand that DOE’s focus and charter must be on energy efficiency and conservation, we 

present these comments to the proposed regulations to include other considerations that impact the 

safe design and usage of these products. Obviously the energy efficiency goals need to 

accommodate these other factors as well. Intertek is available and willing to provide additional 

information and support to the DOE in its consideration of this subject. Please do not hesitate to call 

upon us if we can be of assistance. 

Respectfully Submitted: 

Rick Curkeet, PE 

Chief Engineer-Hearth Products