Any rule on oven energy loss.
Any rule on oven energy loss.
(OP)
I have a walk-in oven that uses X dollars of gas in standby at 300F. Is there any rule-of-thumb as to what would be expected if the standby was changed to 400F?
It seems they cycle considerably faster at 400F.
It seems they cycle considerably faster at 400F.
Keith Cress
kcress - http://www.flaminsystems.com
RE: Any rule on oven energy loss.
TTFN (ta ta for now)
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RE: Any rule on oven energy loss.
RE: Any rule on oven energy loss.
So 300F vs 400F is about 12% higher, so I would expect about 12% more power required.
At higher temps you would need to also factor in radiation loss, but not at these temps.
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P.E. Metallurgy, consulting work welcomed
RE: Any rule on oven energy loss.
So assuming the outside is at say 70F, then the difference is 330/230 = 43% more?, so with a bit of extra convection etc, say 50% more heat loss?
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Any rule on oven energy loss.
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm
RE: Any rule on oven energy loss.
I was visiting a bakery and was surprised to see 7 ovens idling. Some at 300F some at 400F. I asked around trying to discern when they were actually going to run product thru them. It was 1am. The general consensus was, "The baker will be in at 6AM".
Shortly after the president stumbled by and I mentioned, "you have 7 ovens idling here for 5 hours, maybe 4.5 hours if instead they were turned on 30 minutes before the baker shows up."
I asked, "Do you know how much it costs to idle one of these ovens per hour?"
Response, "I have no idea but that would be really nice to know but I have no idea how to figure that out."
So using a stopwatch I figured out how much gas one that was idling at 300F used. Then used the gas tariff tier tables and came up with the cost of idling at 300F.
1/3 Therm or $0.43/hour. A lot less than I expected cost wise, (if not planet-wise). I want to give them the cost but wanted to provide an approximate difference between 300F and 400F too.
Thanks everyone.
Keith Cress
kcress - http://www.flaminsystems.com
RE: Any rule on oven energy loss.
Nevertheless, that number seems low to me, but, maybe that's because they're idling. Something like this supposedly runs 110,000 BTU/(hr? the datasheet seems to be in error) The corresponding electric oven claims 18 kW power consumption, but electric would be more efficient in this case. Assuming, say, 50% of max heat for 5 hours and 7 ovens gives me 19 therms
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm
RE: Any rule on oven energy loss.
These ovens are larger and look like this:
You wheel a six foot tall 4 foot square rack in that the oven lifts off the floor and rotates the entire time.
They're 275,000BTU/hr which I'm sure you realize means the burner power not the oven hourly consumption rate.
They run 14.3 cycles per hour and each cycle runs 31.5 seconds
I get 451 seconds of burn per hour. (That would be 275,000btu/hr)
100,000BTUs = 1 Therm
Here 1 Therm, in the quantity they use, costs $1.26
Keith Cress
kcress - http://www.flaminsystems.com
RE: Any rule on oven energy loss.
While a great hoopla was made of the interns working on his self-named tiny company, they eventually discovered the other facility already had a timer lighting control installed and had just never bothered to use it. Big savings there. I wonder how much the interns cost.
So it remained that once a year the lighting controller that plunged me, and that guy who got an office, into darkness an hour early for two weeks because the facilities manager left an hour early and cared not one whit about the start of daylight saving time, and then on every remaining day, that guy would get to walk the 100 feet to the override and 100 feet back to burn a dollar a day (for him, workaholic that he was) so about $300 a year, and never got that $150 floor lamp. I was there about 25 years, so nearly $8,000, not including the summer heat load extraction for the A/C.
RE: Any rule on oven energy loss.
Lighting is not the only areas where customers could reduce consumption. Is also possible for compressed air, AC, heat, etc. Problem is management just can't see the problem.
And I see it our offices also.
RE: Any rule on oven energy loss.