Certification process

Kiln theory and knowledge

Develop kiln schedules bas...
How does a standard kiln w...
Proper loading of Lumber kiln
Understanding the Extended...
Water spray vs steam spray
Moveable between-deck.
Heat recovery system.
Heating and venting on old...
Steaming lumber.
Heat unit versus coils.

All subjects

Shop online easy

Certification process

As the largest producer of pallet kiln in the US we have probably worked with all the inspection companies and have never had a kiln that did not get approved.

The first time we had a kiln certifiec was in Indiana by Timber Products Inspection (TPI) out of Georgia. Although, TPI no longer requires on-site test run as descriped below, but understand the process may help you understand the kiln operation. We have described the certification process to one of our customers who went through on their container based pallet heat treatment kiln. This process was also done before TPI allow the use of internal sensors; actually, this test run actually help them move towards allowing this.

PDF document with example of certification documentation (4 MB pdf document).

In the case below the certifying company uses nine probes through out the kiln. The probes are placed both high and low, they are also in every second row. They record the initial temperature in the chamber and the the nine pallets. Furthermore, they also record the heat treatment controllers temperature readout.

Thermo- couple	Initial temp.	15 min	30 min	45 min	60 min	75 min	90 min	105 min	120 min	135 min	150 min	160 min	165 min	180 min
1	61	66	78	86	98	108	121	129	136	142	147	Kiln was stopped since it had reached 134F for 30 min in all the pallets.
2	65	69	79	88	100	111	122	131	137	143	149
3	63	67	75	86	99	110	123	130	136	141	147
4	64	71	80	94	107	117	130	139	146	151	159
5	64	71	79	93	107	117	130	139	147	152	160
6	64	67	75	87	100	110	124	132	141	146	154
7	68	71	78	90	103	113	125	133	139	145	151
8	64	82	94	104	118	125	137	144	153	158	162
9	66	74	85	97	113	123	135	144	151	156	163
Kiln Temp	64	83	95	104	117	125	138	145	151	157	161
Controller Temp reading	?	84	99	110	125	130	141	149	155	161	165

The kiln passed on the first try. Our software that records and stores the heat treatment schedules was also approved by TPI. The customer was ready to run. We were very pleased with the outcome of this first certification run, where our unit was able to heat treat a standard pallet (recycle pallet) in two hours and thirty minutes. We would suggest you use 3-4 hours as your guide for capacity calculation to be on the conservative side. There will be some variation in the temperature recording depending on where the sensor is located in the kiln as you can see on the schematic above.

We hope above information has been helpful. If kiln-direct.com can be of any assistance in your process of building or researching the needs for these in your company, please do not hesitate to contact us.

Reinventing ourselves and our kiln designs

Serving you, your company and the industry better by reinventing ourselves. Find out about our new kiln designs and why you should buy from us. Sign up for a newsletter or request additional information about our latest innovations.

On-line store

Kiln controllers, fans, sensors, vents, heat systems and more