Tending Frequency Vs Coal Usage Vs OAT

Post by **Lightning** » Wed. Jan. 18, 2017 9:16 am

Another forecast showing way above normal temps till the 27th. I continue to visit the furnace for shake and load once every 24 hours. The thermostat controlled primary air holds the house at 72-74 degrees. The limit on this stove for once per day tending is around 65 pounds. If heat demand requires more coal, burn cycles must shorten or risk extensive recovery or loss of fire. Here's what burn cycle time vs coal usage looks like.... pounds are per 24 hours. Temperatures are based on an average for 24 hours. For example, a low of zero with a high of 25 would fit in the 18 hour tending schedule since it's average is 12.5 degrees and of course burn times do have some flexibility outside of these parameters but this is a good overall approximation.

Burn cycle time / pounds per 24 hours / OAT
24 hours if < 65 pounds (above 30 degrees)
18 hours if = 65 to 90 pounds (10 to 30 degrees)
12 hours if > 90 pounds (below 10 degrees)

I've never seen heat demand require more than 2 times per day tending. This is very useful information. As I look ahead at forecasts I can lay out a tending schedule that fits around work, sleep and whatever else I need to do.

I just thought this example may help others develope a similar and useful awareness of their stove tending frequency.

freetown fred · Post by **freetown fred** » Wed. Jan. 18, 2017 9:24 am

Yep, that sure cleared things up for me Lee.

Post by **Lightning** » Wed. Jan. 18, 2017 9:26 am

freetown fred wrote:Yep, that sure cleared things up for me Lee.

Happy to help ya Fred....

Just trying to keep it "newbie friendly" lol

Sunny Boy · Post by **Sunny Boy** » Wed. Jan. 18, 2017 11:15 am

I can get my range to hold that much coal, ....... but I'd have to put most of it in the oven.

Paul

Post by **Lightning** » Wed. Jan. 18, 2017 11:53 am

Sunny Boy wrote:I can get my range to hold that much coal, ....... but I'd have to put most of it in the oven.

Paul

Nice

I suppose I could add another parameter if I had a stove with more grate area and could hold 150 pounds.

48 hours if < 40 pounds/24 hours (above 25 degrees)

warminmn · Post by **warminmn** » Wed. Jan. 18, 2017 12:29 pm

Lightning, I love those once a day tendings in mild weather! One of those large Hitzers you've been thinking of would fit right into the amount your using.

ddahlgren · Post by **ddahlgren** » Wed. Jan. 18, 2017 12:42 pm

Wouldn't degree days be better than averaging high and low? What about wind and infiltration with high wind? I know with my place by the water if the wind picks up it takes a bunch more than a calm clear night.

Post by **Lightning** » Wed. Jan. 18, 2017 3:12 pm

ddahlgren wrote:Wouldn't degree days be better than averaging high and low? What about wind and infiltration with high wind? I know with my place by the water if the wind picks up it takes a bunch more than a calm clear night.

Heated Degree Days are based off the average temp for that "day". Yes high winds would impact usage to an extent, this is just a generalization for laying out a tending schedule when viewing a forecast. HDDs would look like this -

Burn cycle time / pounds per 24 hours / HDDs
24 hours if < 65 pounds (less than 35 HDDs)
18 hours if = 65 to 90 pounds (55 to 35 HDDs)
12 hours if > 90 pounds (more than 55 HDDs)

warminmn wrote:Lightning, I love those once a day tendings in mild weather! One of those large Hitzers you've been thinking of would fit right into the amount your using.

I like the once a day also