vents in DH kiln

brdmkr · March 15, 2009, 11:56:50 PM

I am installing vents and noticed in the plans that they open to the outside, meaning I'll have to go inside to open them. I have installed the intake vent, but I want to make sure before installing the exhaust vent. Is there a reason that they open to the outside (other than it looks better)?

karl · March 16, 2009, 10:15:09 PM

Don't recall any reason for them to being installed to operate from the inside. I will be installing ours to open from the outside when we build the new kiln.Probably will locate them under some sort of roof to protect the mechanism from the weather though.

brdmkr · March 16, 2009, 10:42:42 PM

Thanks Karl. I found in the plans where you can do it either way, but they say it is more convenient with the mechnism on the inside. I think it would be easier the other way.

scsmith42 · March 16, 2009, 11:00:32 PM

I open mine from the outside...

woodhick · March 17, 2009, 08:57:29 PM

I put mine in so they open from outside.

brdmkr · March 17, 2009, 10:15:33 PM

I'm thinking I will do the same. Thanks for the replies.

E_King · March 27, 2009, 08:26:34 PM

I am in the process of building a building for a Nyle L200, will i have to install a drain in the floor ,

scsmith42 · March 27, 2009, 11:34:03 PM

Re the floor drain, no.

To properly operate your kiln, you need to be able to precisely control the amount of moisture being removed per day. Thus, you want all moisture being removed to go through the DH unit itself.

OneWithWood · March 30, 2009, 11:55:25 AM

Quote from: scsmith42 on March 27, 2009, 11:34:03 PM
Re the floor drain, no.

To properly operate your kiln, you need to be able to precisely control the amount of moisture being removed per day. Thus, you want all moisture being removed to go through the DH unit itself.

and exiting via a drain to the outside.

You can get a good feel for how the kiln is operating by observing the stream of drips flowing out the drain.

brdmkr · March 30, 2009, 12:05:27 PM

I still haven't fired my kiln up, but the talk of the drain makes me wonder. Why do we even have vents? I have not read anything in the manual about actually using them. Are they used to lower the temp when you exceed the programed temp? As I said, I have not run the kiln yet, so if I am asking something stupid, just say so (but please answer anyway ;)) Oh, I should have the first charge cooking before the weekend 8). It is a load of pine beams, so I doubt that I will be too worried about temp.

OneWithWood · March 30, 2009, 12:16:24 PM

The vents are there for temp control. It is possible to run the compressor enough to greatly exceed the set temp. Or, believe it or not, it has been know to happen that the initial temp is set too high and the intial RH set too low which can cause case hardening. Should this happen you need a way to cool the pile. The vents provide a way to bring the temp down.

brdmkr · March 30, 2009, 10:35:14 PM

My controller works by running the compressor a set percentage of the time. If I am not there and have the controller set for 100% will it not kick off if it exceeds temperature?

OneWithWood · March 31, 2009, 10:33:31 AM

If you have the controller set at 100%RH will the compressor even come on?

There are a couple of different controllers supplkied with Nyle kilns. It depends on who the retailer is and what specs they gave to Nyle I think. Call Nyle. They will be happy to explain the operation of the vents given the controller you have.

brdmkr · March 31, 2009, 07:48:12 PM

The controller that I have runs the kiln for a certain percentage each hour. If set for 50% it runs 30 min every hour. 100% it runs constantly.

Den Socling · April 08, 2009, 04:16:07 PM

If you live in the north and put the vents opening outward, they can get iced and won't close. It depends on design, though.

DR Buck · April 08, 2009, 06:14:37 PM

The vent also help with over temp control during the summer months. It's not uncommon to have my temp controller set at 120° and the outside temp goes up over 90°. The kiln temp can go up over the scheduled temp real easy.

I finally went to the automatic vents 2 years ago. So much better. 8) Set and forget.

kelLOGg · April 25, 2009, 03:54:21 PM

Quote from: OneWithWood on March 30, 2009, 12:16:24 PM
The vents are there for temp control. It is possible to run the compressor enough to greatly exceed the set temp. Or, believe it or not, it has been know to happen that the initial temp is set too high and the intial RH set too low which can cause case hardening. Should this happen you need a way to cool the pile. The vents provide a way to bring the temp down.

If venting the heat is necessary why do we even insulate the kiln - particularly in the south - other than to set the pitch in pine? Mine will easily reach 120 degrees in the winter (kiln is an insulated 450 cubic foot chamber with no vents and a room DH inside so I kiln dry after air drying). After reading this thread I started venting mine this spring by opening the door for an hour or so. The loss of humidity during venting seems to speed up the drying. I have assumed that this is because the room DH does not condense as well at 120 deg as it does at 90.

Your experienced comments are welcome since I am trying to figure out if my drying "schedule" is reasonable.

brdmkr · April 25, 2009, 09:00:20 PM

Kellogg

I have been over 20 degrees over temp every day. I crack the doors until the temp goes down. Sometimes, I leave them open all day. I am currently drying SYP and I don't think you can dry it too fast. With oak, the compressor should not run as much, so hopefully the overheat will not be as much problem.

kelLOGg · April 27, 2009, 07:42:06 AM

When I built my kiln I did not use vents because I read in http://www.ca.uky.edu/agc/pubs/for/for55/for55.htm
that they were not necessary in a DH kiln. That runs counter to the info in this thread and also to my experience. Now that I am adding them I have some questions:

1. Should the entrance and exit vents be at different heights to allow for thermosiphoning?

2. If I use fans in the vents what is a good source? (I didn't see them on Nyles site)

3. Automatic or manually controlled vents?

Ronnie Hubbell · April 27, 2009, 09:59:33 AM

This whole venting issue is really blowing my mind on trying to establish some kind of "schedule" on my new kiln also. I also have a very tight insulated box which will tend to overheat easily while using only gentle DH corrections trying to keep the compressor from coming on and creating more heat. Then when I vent even a little, my Humidity actually lowers trying to adjust to the outside atmosphere, causing a cool down inside and thus a vicious circle of "adjustments". Trying to arrive at a temp and humidity combination that will produce any condensation out the drain is almost impossible with any consistency. What's Going On ???
Thanks Ronnie