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### NSPS Regulated Product Applicability/Definition Pro posal June 6, 2011

Prepared for HPBA by David Menotti and Bob Ferguson

Wood Heaters

A Wood Heater is an enclosed, solid fuel burning a ppliance capable of and intended for space heating (rather than whole house heating), or space heating and domestic water heating. Wood heaters may or may no t include air ducts to deliver some portion of the heat produced to areas other th an the space where the wood

heater is located. Wood heaters include:

Free-standing Wood Heaters –Wood Heaters that are installed on legs, on a pedestal or suspended from the ceiling. These prod ucts generally are safety listed under UL-1482, UL-737 or ULC-S627. Fireplace Insert Wood Heaters – Wood Heaters intended to be installed in masonry fireplace cavities or in other enclosures. These appliances generally are safety listed under UL-1482, UL-737 or ULC-S628

. Built-in Wood Heaters – Wood Heaters that are intended to be recessed in to the wall. These appliances generally are safety listed under UL-1482, UL-737,

UL-127 or ULC-S610.

Pellet Space Heaters

A Pellet Space Heater is an enclosed pellet or biom ass burning appliance capable of and intended for space heating (rather than whole house heating) , or space heating and domestic water heating. Pellet Space Heaters include a fuel storage hopper or bin and a fuel feed system. Pellet Space

Heaters include:

Free-standing Pellet Space Heaters –Pellet Heaters that are installed on legs or on a pedestal or other supporting base. These prod ucts generally are safety listed under ASTM E1509, UL-1482, ULC S627 or ULC-O RD C1482. Pellet Space Heater Fireplace Inserts – Pellet Heaters intended to be installed in masonry fireplace cavities or in other enclosure s. These appliances generally are safety listed under ASTM E1509, UL-14 82, ULC-S628 or ULCORD C1482. Built-in Pellet Space Heaters – Pellet Heaters that are intended to be recessed into the wall. These appliances generally are safe ty listed under ASTM E1509,
UL-127, ULC-S610 or ULC-ORD C1482.

Single Burn Rate Heaters [Limited Burn Rate or Uti lity Heater]

No recommendation at this time. [See background in formation section]Page 2 of 2

Hydronic Heaters

Hydronic Heaters are solid fuel-burning appliances intended to heat whole buildings (or substantial portions thereof) either as stand-alone systems or as additions to existing heating systems. Hydronic heaters may be located outdoors or indoors, may be fueled by wood, pellets, or biomass materials, and may include alternate or backup fossil fuel burners or electrical heating elements. The heat produced by a hydronic heater i s transferred by a heat exchange medium through piping from the appliance to another heat e xchanger or directly to the spaces being heated. Domestic hot water may be produced as wel l. Safety standards for hydronic heaters include UL-2523 and CSA B366.1. Hydronic Heaters in clude:

On-Demand

Hydronic Heaters– Hydronic Heaters that primarily produce heat in response to instantaneous heating needs. These heaters general ly cycle as needed to maintain a delivered fluid outlet temperature within a specified range. Full Thermal Storage Hydronic Heaters – Hydronic heaters that include adequate thermal storage capacity (generally in the form of insulate d water tanks) to absorb all heat produced

from at least one full load of fuel. Heat is then released to the heating system as needed from the storage. These appliances generally operate at one burn rate and do not cycle. Partial Thermal Storage Hydronic Heaters – Hydronic heaters that include thermal storage capacity adequate to absorb a portion of the heat p roduced from a load of fuel. The addition of some thermal storage dampens the frequency of cy cling in response to heat demand. Heat is delivered to the heating system either directly from the heater or from storage.

Warm Air Furnaces

Warm air furnaces are solid fuel-burning appliances intended to heat whole buildings (or substantial portions thereof) either as stand-alone systems or as additions to existing heating systems. Domestic hot water may be produced as wel l. Warm air furnaces may be located indoors or outdoors, may be fueled by wood, pellets , or biomass materials, and may include alternate or back-up fossil fuel burners or electri cal heating elements. The heat produced by a warm air furnace is typically transferred through d ucting as heated air. Safety standards for

warm air furnaces include UL-391 and CSA B366.1.

Masonry Heaters

Masonry heaters are site-built (using local materia ls or a combination of local materials and manufactured components) or site-asse mbled (using manufactured components), solid-fuel burning heating appliances constructed mainly of refractory materials (e.g., masonry materials or so apstone) in which the heat from intermittent fires burned rapidly in their fireboxe s is stored in their refractory mass for slow release to building spaces. They typically have an interior construction consisting of a firebox and heat exchange channels built from refractory components, through which flue gases are routed. A STM E-1602 “Standard Guide for Construction of Solid Fuel Burning Masonry Heat ers” provides design and construction information for the range of masonry h eaters most commonly built in the United States. The site-assembled models are g enerally listed to UL-1482.Page 3 of 3

Coal-Only Heaters

Coal-Only Heaters are enclosed, coal-burning applia nces capable of space heating, or space heating and domestic water heating, which have all of the following

characteristics: (a) An opening for emptying ash that is located near th e bottom or side of the appliance; (b) A system that admits air primarily up and through t he fuel bed; (c) A grate or other similar device for shaking or dist urbing the fuel bed or a power driven or mechanical stoker; (d) Installation instructions that state that the use o f wood in the appliance, except for coal ignition purposes, is prohibited by law; and (e) A safety listing under accepted American or Canadi an safety codes, as documented by a permanent label from a nationally r ecognized certification body.

Cookstoves

Cookstoves are solid-fuel burning appliances that a re designed primarily for cooking food and that have all of the following characteristics: (a) An oven with a volume of 0.028 cubic meters (1 cubi c foot) or greater with an oven rack; (b) A device for measuring oven temperature; (c) A flame/exhaust path that is routed around the oven ; (d) A shaker grate; (e) An ash pan; (f) A ash clean-out door below the oven; (g) The absence of a fan or heat channels to dissipate heat from the appliance; (h) A cooking surface area measured in square inches or square feet which is 1.5 times greater than the firebox volume which is measured i n cubic inches or cubic feet. Example: A firebox of 2 cubic feet would require a cooking surface of 3 square feet; and (i) A portion of at least four sides of the oven that a re exposed to the flame path during the heating cycle of the oven while a flue gas bypass w ill be permitted for temperature

control.



### Background Information

Regulated Product Categories

IN GENERAL: The definitions of regulated heater ca tegories are framed more generally than the definition of fireplaces, which are exempt. Ou r thinking was that the definitions needed to be broad enough to assure that nothing in the category was excluded. Beyond that, the issue for regulated appliance categories was making sure that the appliance got matched appropriatelyPage 4 of 4

with the applicable test method and set of emission limits. These decisions are going to be made, in the first instance at least, by the test l aboratories, and we see little room for disagreement in all but the most extreme possible c ases. It is unlikely, for example, that there will be much difficulty in distinguishing between a hydronic heater and a warm air furnace, or between either of these appliance types and room he aters like a wood stove or a pellet stove.

Wood Heaters

The Wood Heater product category generally continue s with the definition that has been in place in the current NSPS, with some modest editing for a ccuracy and clarity, and the addition (again for clarity) of definitions of the subcategories th at comprise the broader category. These products are intended for space heating and include controls to regulate the heat output. Subcategories of wood heaters include free-standing, f ireplace inserts and built-ins. The safety listings for these products are generally specific to wood-fired space heaters although the safety listings can overlap between some sub-categories. For example, in the United States, fireplace

inserts are tested and listed to the same standard as free-standing heaters (while in Canada, they have separate standards). As discussed in the fire place section, the operating characteristics of built-in heaters are very different than those of f ireplaces; however, to satisfy local building inspectors, some built-in heaters are tested and li sted to the factory-built fireplace safety standard since in outward appearance, they share the same in stallation characteristics of being recessed into the wall with very low clearances to adjacent combustible materials.

Pellet Space Heaters

Pellet/Biomass Heaters have evolved appreciably sin ce the first NSPS was promulgated. Pellet space heaters, intended to heat a room or rooms rat her than whole buildings, now include the same sub-categories as wood space heaters, includin g free-standing, fireplace inserts and built-in designs. Fuel types have expanded beyond wood pell ets to include grains (such as corn), shells, hulls and pits and other pelletized biomass such as grasses. The safety listing to ASTM E1509 is one way to differentiate pellet/biomass space heate rs although heaters in this category are

sometimes listed to UL solid fuel heater standards instead. The primary delineator, however, is the presence of the fuel storage and feed system. Hoppers are included to hold a supply of fuel which is automatically fed to the firebox to be bur ned in a specially designed burn pot. The fuel may be fed to the burn pot from above, from behind or from below but in all cases, the same result is achieved. That is, the fuel is fed to be burned in the heater on an “as needed” basis in response to the heat demand rather than as batch fe eding of large loads of fuel typical to cord wood heaters. By limiting the fuel feed to only th e amount needed to produce the desired heat output in conjunction with carefully metered primar y and secondary combustion air, pellet/biomass combustion provides a more consisten t and more predictable combustion environment. The unique fuel handing system, the s afety listing, and the intended use to heat a room or rooms rather than an entire building provid e clear differentiation for pellet heaters.Page 5 of 5

Single Burn Rate Heaters [Limited Burn Rate or Uti lity Heater]

We understand that this product category has been i ncluded in the NSPS to help close a loop hole that was created in the original NSPS. Howeve r, uncertainty on our part regarding EPA’s intentions for this category made it extremely diff icult for us to provide a definition for the appliance category. In the end, we decided that t he better course was to hold off on attempting to develop a definition until we had a clearer unde rstanding of EPA’s intentions for this subcategory.

Hydronic Heaters

Hydronic Heaters as a product category include a nu mber of variations covering where they are installed, how they deliver the heat that is produc ed and the type of fuel burned. Hydronic heaters can be pressurized or atmospherically vente d. However, hydronic heaters are building heaters, not room heaters and are often tied into e xisting heating systems within the building. Outdoor hydronic heaters are located external to th e building being heated and typically include a weather-tight enclosure. Indoor hydronic heaters are located inside the building envelope. There are hydronic heaters that burn cordwood and o thers that burn particulate biomass fuels like wood pellets, wood chips, granular fuels (for examp le: corn, shells, hulls or pits) or other pelletized biomaterials (for example, grasses). All hydronic heaters deliver the heat produced as a heated fluid, most often water or in some cases a s steam. Hydronic heaters typically include safety listings to UL-2523 or to CSA B366.1.

Hydronic heaters can be further sub-categorized by the way they produce and deliver heat. Ondemand Hydronic Heaters typically include substanti al water volume on board the heater connected in a loop to the building heating system. They operate in a manner that is similar to an oil or gas-fired hydronic heater in as much as the water temperature in the heater is maintained between specific control limits by cycling the comb ustion on and off (or up and down) as needed based on the heat demand applied by the building. A second sub-category is for heaters that take a very different approach to meeting heating demand . Full Thermal Storage Hydronic Heaters include water volume, either on-board the heater or within an external insulated storage tank, of sufficient volume to store all of the heat produced from at least a full load of fuel. These heaters generally operate at a high burn rate for the full duration of the fuel load combustion. The building heat demand is typically satisfied by draw ing from the stored heat rather than directly from the heater. These systems are typically fired once or twice per day depending storage volume and heating demands. Partial Thermal Storag e Hydronic Heaters bridge the gap between the first two sub-categories. These hydronic heate rs typically have relatively high water volume as part of the overall system. Some have relativel y low on-board water volume but include an external thermal storage tank as a required part ofthe system while others may have all water onboard. Specific installation details can vary from model to model but the concept remains the same across this sub-category. These systems suppl y part of the heat produced directly to the building heat load and store any excess heat in an insulated storage tank for later use. If the maximum thermal storage capacity of the system is r eached before the fuel load is fully consumed, these heaters may begin to cycle based on the building heating demand in a manner similar to the on-demand hydronic heaters or may si mply extinguish combustion in the firebox.Page 6 of 6

These systems can provide the advantage of delaying the on-off cycling until later in the burn cycle where fewer particulate emissions are produce d.

Warm Air Furnaces

Warm Air Furnaces are designed to heat buildings ra ther than as space heaters. They may be stand- alone systems or be tied to existing warm ai r heating systems. Typical characteristics include a plenum with heat exchanger to extract hea t from the firebox exhaust, ducting to deliver warm air to the building and to return cool air to the furnace, a blower to establish the heat flow to the building, thermostatic controls to regulate heat output, a combustion air blower to deliver primary and secondary air to the firebox and over-t emperature limit controls to insure that safe temperature limits for adjacent combustible materia ls are not exceeded. Warm air furnaces are typically located within the building envelope but can be located outside the building. There are

warm air furnaces that burn cordwood and others tha t burn particulate biomass fuels like wood pellets, wood chips, granular fuels (for example: c orn, shells, hulls or pits) or other pelletized biomaterials (for example, grasses). Warm air furna ces are typically on-demand type heaters, reacting to the heating demands of the building by regulating the burn rate in the firebox or by cycling on and off as needed but it is conceivable that warm air furnaces could be used in conjunction with heat storage in some form. Warm a ir furnaces typically include safety listings

to UL-391 and CSA B366.1.

Masonry Heaters

Masonry Heaters are solid-fuel burning appliances t hat designed to heat by releasing heat stored in the refractory mass of the appliance to the spac es to be heated. They can be either site-built or site-assembled, involve burning batch-loaded fuel a t high burn rates, and typically have designs that route flue gases through passages in the refra ctory mass to facilitate heat exchange and heat storage. These characteristics are embodied in the proposed definition. Site-built masonry heaters must meet applicable building codes, but ar e not listed pursuant to US or Canadian safety standards; site-assembled models are generally list ed to UL-1482.

Coal-Only Heaters

The draft incorporates the definition of this appli ance type from the current NSPS, with some modest editing for greater clarity and ac curacy.

Cookstoves

The draft incorporates the definition of this appli ance category from the current NSPS, with the modifications agreed to recently to tighten up the definition and minimize the potential for abuse.