Vented Log Set Sizing
Determining which size Hargrove vented gas log set will work best with your fireplace is fairly simple, but is not an exact science, due to differences in fireplace shape and construction.  By taking a few measurements of the inside of the fireplace, as described and shown in the diagrams below, you and your authorized Hargrove Hearth Products dealer will be able to decide which gas log set will best fit your home.  You may print these diagrams and use them to record your measurements to take with you when you visit your Hargrove dealer.  Hargrove log set sizes are based on the approximate length of the front log of the set, and for sets with two piece front logs, the combined length of the two log pieces, when installed, will correspond to the size of the set, so a 24" set will have a front log that is approximately 24".  Please note that the length of the front log(s) vary, and a 24" set may actually have a front log whose length is 23" to 25".
 
All measurements should be made from the inside surfaces or firebrick of the fireplace.  Front width (A) and depth (C) are the most important dimensions for vented gas log sizing.  These measurements should be taken from the fireplace floor, inside the hearth or lip of the fireplace, and behind any wire screens or railing that may be permanently attached to the fireplace.  In deeper fireplaces, front width measurements can be taken 6" to 8" from the front, allowing better centering below the flue of the fireplace.

Subtract 8" from the front width (A) dimension, for the best overall sizing of the log set.  This allows 4" on either side of the front log of the set, giving plenty of room for valve clearance and centering the log set in the fireplace.  If desired, side clearances as low as 4" (2" per side) will normally work on sets without safety pilot controls, and many people prefer the look of a very full fireplace, which this arrangement helps create.
   
  Minimum Depths for vented log sets are:
  15" to 21" standard EB & S4      13"
  24" to 30" standard EB & S4      14"
  36" to 48" standard EB & S4      15"
  Kodiak Double-Stack (all sizes)      21"
  Kodiak Triple-Stack (all sizes)      31"
  Mountain Timber (21" EB)      13"
  Mountain Timber (24"-30" EB)      14"
  Mountain Timber (30"-48" ES)      20"
  See-Thru Standard (all sizes)      19"
  See-Thru Shallow (all sizes)      15"
  See-Thru Narrow (Radco/CSA)      13"
  Summit Oak (all sizes)      26"
Rear width (B) is rarely a critical dimension with single-sided vented gas logs, unless the rear of the fireplace is extremely narrow, however, rear width is an important consideration for the Kodiak Double and Triple-Stack series sets, as these require front and rear widths of similar dimension when installed with a safety pilot control.  Height (D) is also rarely a problem, however, we still recommend giving both of these dimensions to your Hargrove Hearth dealer when sizing your log set.  The height of Hargrove standard single-sided and see-thru log sets are 16", Mountain Timber sets on the Ember Supreme (ES) burner system are 20", Kodiak Double-Stack sets are 20", Kodiak Triple-Stack sets are 24", and all Summit Oak sets are 26".

 
Vent-Free Log Set Sizing
Determining vent-free gas log set size is similar to the process for vented logs, but requires consideration of additional factors, such as room volume, minimum clearance to combustible materials outside the fireplace and proper clearances between the log set and the inside walls of the fireplace, which are critical for vent-free operations.  By taking a few measurements of the inside of the fireplace and of the room in which you intend to place your vent-free gas log set, as described and shown in the diagrams below, you and your authorized Hargrove Hearth Products dealer will be able to decide which gas log set will best fit your home.  You may print these diagrams and use them to record your measurements to take with you when you visit your Hargrove dealer.  As with our vented log sets, Hargrove vent-free log set sizes are based on the approximate length of the front log of the set, and for sets with two piece front logs, the combined length of the two log pieces, when installed, will correspond to the size of the set, so a 24" set will have a front log that is approximately 24".  Please note that the length of the front log(s) vary, and a 24" set may actually have a front log whose length is 23" to 25".
 
Room volume should be measured first, to determine the maximum BTU per hour that the room can support, per the National Fuel Gas Code's definition of unconfined space.  The National Fuel Gas Code defines an confined space as a space whose volume is less than 50 cubic feet per 1,000 BTU per hour of the aggregate input rating of all appliances installed in that space, and defines an unconfined space as a space whose volume is not less than 50 cubic feet per 1,000 BTU per hour of the aggregate input rating of all appliances installed in that space.  Rooms communicating directly with the space in which the appliances are installed, through openings not furnished with doors, are considered a part of the unconfined space.  Vent-free gas logs should not be installed in a confined space, as defined above, or in homes of unusually airtight construction, unless provisions are made to supply adequate combustion and ventilation air to the space.  Calculate the maximum BTU per hour the room can support by following the steps below.
 
Step One: Determine the volume of space in cubic feet — Length of Room X Width of Room X Height of Room = Cubic Feet of Space.  (Include adjoining rooms with doorless passageways)

Example: 24' (L) X 16' (W) X 8' (H) = 3,072 cu. ft.
 
Step Two: Multiply the volume of the space by 20 BTU/hour, to determine the maximum BTU the space can support.

Example: 3,072 cu. ft. X 20 BTU/Hr. = 61,440 BTU/Hr.
 
Step Three: Add the BTU/hour of all fuel burning appliances in the space.

Vent-Free Heater          BTU/Hr. (Gas Log Set)
Gas Appliance #1          BTU/Hr. (Wall Heater)
Gas Appliance #2          BTU/Hr.  
Total          BTU/Hr.  

Example: gas log set 26,000 Btu/Hr. + wall heater 25,000 Btu/Hr. = 51,000 Btu/Hr.
 
In the example above the room is an unconfined space, because the 61,440 Btu/Hr. the space could support is higher than the 51,000 Btu/Hr. total of the appliances in the room, and the gas log set could be used in the room.  If the total Btu/Hr. was higher than 61,440, the room would be a confined space, and additional fresh air must be provided before using these appliances in the room.
 
Fireplace measurements should be made from the inside surfaces or firebrick of the fireplace.  These measurements should be taken from the fireplace floor, inside the hearth or lip of the fireplace.  In deeper fireplaces, front width measurements can be taken 6" to 8" from the front of the fireplace if desired, as long as minimum clearances can still be maintained.

Once fireplace measurements have been taken, they should be compared with the minimum fireplace dimensions for Hargrove vent-free gas logs sets listed below, to ensure proper clearances can be achieved.
 
Minimum Fireplace Dimensions for Vent-Free gas log sets are:
  Front Rear    
Standard & Single Burner Sets Width Width Depth Height
18" & 21" sets 28" 18" 13" 17"
24" sets 32" 22" 13" 17"
30" sets 36" 22" 13" 17"
         
Cumberland Char & Mountain Laurel sets        
18" sets 28" n/a 12" 16"
24" sets 32" n/a 12" 16"
30" sets 36" n/a 12" 16"
         
Highland Glow sets        
22" sets 28" n/a 12" 16"
26" sets 30" n/a 12" 16"
         
Timberland Glow sets        
22" sets 28" n/a 12" 16"
26" sets 30" n/a 12" 16"
         
Woodland Glow sets        
21" sets 30" 20" 15" 18"
24" & 30" sets 36" 22" 15" 18"
         
 
All minimum clearances must be met for safe and proper operation of your vent-free log set.
 
Another consideration when sizing your vent-free gas log set is clearance to combustible materials.

While a vented fireplace releases most of its heat through the chimney flue, almost all of the heat produced by a vent-free log set radiates out of the fireplace and into the room in which it is installed, which could present a fire hazard if combustible materials are placed too close to the source of this heat. 

Minimum clearances to combustible materials must be determined to maintain proper side clearances to the mantle, ceilings and walls surrounding the fireplace, which are detailed in Figure 2.
Flat mantle minimum clearances above the fireplace, for fireplaces without a canopy installed, are illustrated in Figure 3.  Note that heat resistant material, such as gypsum board, sheet rock, slate, tile, marble, etc. should be used to cover the first 8 inches above the fireplace in applications where no canopy is used.  Also note that longer projections from the wall require greater clearances from the top of the fireplace, as shown in Figure 3.
Fireplaces using a canopy require less clearance above the fireplace opening than those without a canopy, as shown in Figure 4, and do not require heat resistant materials be installed immediately above the fireplace top opening.

Hargrove Hearth Products recommends the use of a fireplace canopy with your vent-free fireplace and gas log set.
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