Costs of running a heat treat furnace??

KenH

Well-Known Member
Tim, you're right, my oven seems very slow to heat up. There is no real voltage drop involved since the recept is 2 ft from breaker panel. I do have two fire brick laying in bottom of oven. These fire brick allows the blades to be closer to center of oven, close to TC tip. How important this is I'm not sure.

At 20 min = 1050°F
At 38 min = 1330°F
At 50 min = 1500°F
1 hr 20 min = 1835F
1 hr 40 min = 1975°F
1 hr 45 min = 1971°F to 1975°F

Open door put in 3 coupons, closing door each coupon, temp dropped to 1885F. Returned to 1975°F in 5 to 10 minutes. Perhaps if I allowed the oven to stabilize longer there might be less temp drop during putting blades inside.

That gives a good idea how slow my oven is. I remember before I put the fire brick in it seems to heat up faster, but not sure how much.
 

jaxxas

Well-Known Member
Tim, you're right, my oven seems very slow to heat up. There is no real voltage drop involved since the recept is 2 ft from breaker panel. I do have two fire brick laying in bottom of oven. These fire brick allows the blades to be closer to center of oven, close to TC tip. How important this is I'm not sure.

At 20 min = 1050°F
At 38 min = 1330°F
At 50 min = 1500°F
1 hr 20 min = 1835F
1 hr 40 min = 1975°F
1 hr 45 min = 1971°F to 1975°F

Open door put in 3 coupons, closing door each coupon, temp dropped to 1885F. Returned to 1975°F in 5 to 10 minutes. Perhaps if I allowed the oven to stabilize longer there might be less temp drop during putting blades inside.

That gives a good idea how slow my oven is. I remember before I put the fire brick in it seems to heat up faster, but not sure how much.

My Evenheat is the 220 volt 24" model, and it's been a bit since I used it but I don't remember it taking more than 40 minutes or so to get to 1500° F. I could test that if you like or even up to 1975° F if needed.
 

KenH

Well-Known Member
I forgot to mention I've got the 18" 240 vac Evenheat oven. Note your 40 minutes or so is about the same as my time of 50 minutes to 1500F.

It would be interesting to see how long your oven took to 1975F to compare to my oven. Remember, I do have 2 fire brick in bottom of the oven. The brick does make it take a bit longer, but not sure how much longer. I should test without brick to check time.
 

jaxxas

Well-Known Member
So I ran the test.





summary ( I was trying to match your previously posted schedule.)

@ 16 min 1050° F
@ 26 min 1330° F
@ 38 min 1500° F
@ 1 hr 4 min 1835° F
@ 1 hr 21 min 1975° F

I had changed the hold time from 2 mins to 10 minutes late in the firing schedule just watch the temps for a bit after reaching temp. Basically after it reaches 1975° F it just bounces between 1968° F and 1975° F with the controller clicking on and off a bunch for the 10 minutes that I monitored. I have a bunch of pics I could email you if you like.
 

John Wilson

Well-Known Member
So I ran the test.





summary ( I was trying to match your previously posted schedule.)

@ 16 min 1050° F
@ 26 min 1330° F
@ 38 min 1500° F
@ 1 hr 4 min 1835° F
@ 1 hr 21 min 1975° F

I had changed the hold time from 2 mins to 10 minutes late in the firing schedule just watch the temps for a bit after reaching temp. Basically after it reaches 1975° F it just bounces between 1968° F and 1975° F with the controller clicking on and off a bunch for the 10 minutes that I monitored. I have a bunch of pics I could email you if you like.
This looks just about exactly like what i see with my oven. (220V 24” oven)
 

KenH

Well-Known Member
Joe, John, thanks for the info. Looks like ya'll's oven heats up a bit faster than my oven does. Thank ya'll for doing the testing.
 
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