Rack Inconsistensies Continued

[mattchibi]

So, still having problems with my rack. Only got the one lesser in there, but shes in a tub with optimal conditions. Her rack has 90-95 on hot spot, 79-81 in cool side, its a 12 quart tub with aspen bedding, one hide and one water dish.

The temps Im achieving inside the tubs are: (all of them have 79-81 cool side)

Top shelf: 87-88 hot spot
2nd shelf: 91-95
3rd shelf: 91-95
4rth shelf: no tubs yet, broken on shipment

The temps of the flexwatt are:
Top shelf: 92-96
2nd shelf: 96-102
3rd shelf: 96-102
Bottom shelf: 92-95

What the heck is going on?? I have used accurate ways of taking temps including my Flukers thermometer, a few probe thermometers and my IR gun (which gave me similar readings as my other thermometers). I am using a oil filled heater regulated by a Ranco, set at 80 F.

I feel like my flexwatt might be dysfunctional, but I have no idea. If it was not working properly, wouldnt it not heat up at all? The flexwatt is snaked all the way through so the only solution would be to get the seller to send me some new flexwatt to run through myself. I can't increase the temps on the thermostat anymore without risking over-heating the second and third shelves so i have no clue what to do! I thought when I bought an expensive rack like this it would be plug and play but so many problems have arised Thanks for reading

[mattchibi]

And I dont know if it makes a difference, but after reading Kitedemon's recent post on here, I have my herpstat probe foil taped on top of the flexwatt, on the second shelf. By foil taped I mean a big piece of foil tape that covers the entire probe. I didnt want ambient temps affecting it which is why I did it like that. Should I change it to electrical tape/whats the best way to secure the herpstat probe onto the heat tape? Thanks again

[kitedemon]

Guessing here but is the flexwatt wired from the bottom to the top? if it is the line loss may account for this variation some is unavoidable usually it is a balancing act between top and bottom it is odd however usually the top is the hottest and bottom coolest. I have my flexwatt all running off a single wire so rather than one piece running into the next they are all wired off a central lead of wire. I have fairly contestant temps on the flexwatt I however do not heat the room so I have secondary and back up heat sources too that changes my situation from the norm quite a lot.

[kitedemon]

"Do not use aluminum tape to secure the probes. This will cause false readings and poor regulation."

from the herpstat 4 manual last page. http://spyderrobotics.com/products/herpstat4_manual.pdf

I found that I got better readings when I switched I also lay down al. tape first I believe it helps transfer heat from a larger area to the probe evening out some of the variations in the flexwatt. (2 inch strip across the 'stripes' in the flexwatt) I cover the whole thing with eletrical tape and al. tape over that. (eletrical tape doesn't stick as well) I found it brought the set point to 95 and that delivers 89-93 bottom to top on my rack. I feel better not having the herpstat set too far away from a 'safe temp' my fail safe is set to 99.

[mattchibi]

Guessing here but is the flexwatt wired from the bottom to the top? if it is the line loss may account for this variation some is unavoidable usually it is a balancing act between top and bottom it is odd however usually the top is the hottest and bottom coolest. I have my flexwatt all running off a single wire so rather than one piece running into the next they are all wired off a central lead of wire. I have fairly contestant temps on the flexwatt I however do not heat the room so I have secondary and back up heat sources too that changes my situation from the norm quite a lot.

This whole issue is boggling my head right now, Ive contacted the seller to see what he thinks and if his customers have encountered this before. I just want to know if its something wrong with what Im doing on my end or if its the actual setup of the rack.

The flexwatt is snaked from bottom to top, with the wires coming out the back of the top shelf. There are actually small slits on the sides where I could re-wire the flexwatt so that I have a seperate strip on each shelf, but that would be a little annoying considering I suck at putting things together and the reason I paid a whole paycheck for this rack is so I wouldnt have to put in extra time to deal with this stuff. Heres a few pictures of the whole setup

Room:



Top Shelf:


Second Shelf, with herpstat probe:


Bottom Shelf:


Thanks Kitedemon.. So if I am understanding correctly, the probe placement should be from bottom to top: Flexwatt - Big piece of aluminum tape - Herpstat probe - small piece of electrical tape - Foil tape?

[kitedemon]

basically that is what I use.

Foil tape - probe electrical tape covering both tape and probe and foil tape covering electrical tape.

Your flexwatt makes an s through the rack? The electrical plug is on the top of the flexwatt? if that is the case my thought is not valid the bottom would then be the end of the line. Also a single un cut flexwatt strip should be more or less even.

That is very odd to me heat rises the flexwatt might loose some power over distance but if the start is the top that isn't it either. Stumped. My rack is also PVCx and my warmest is the top. It is odd. The pic of the top shelf failed to load could you re post it?

Sorry it just appeared...

[kitedemon]

Ok I have a thought... It is a bit of a band aid but if it works...

The top flex watt seems to be set deeper than the other one you posted. Is it??

If that is the case that could be the issue heat dissipates quickly in air you might try adding a spacer under it to raise it up some. make sure the spacer will take the heat I personally would use pvc but I have some laying around a thin bit of plexy might work just make sure it won't get too hot and cause a fire.

[mattchibi]

Ok I have a thought... It is a bit of a band aid but if it works...

The top flex watt seems to be set deeper than the other one you posted. Is it??

If that is the case that could be the issue heat dissipates quickly in air you might try adding a spacer under it to raise it up some. make sure the spacer will take the heat I personally would use pvc but I have some laying around a thin bit of plexy might work just make sure it won't get too hot and cause a fire.

The guy who made the rack for me uses the same plans (owns the rights) to RBI racks. They are not made by Rich at RBI, but are of the same design.

The top flexwatt is at the same depth as all of the other shelves, Im really stumped lol. I'll wait till I hear from the seller and I'll update you on what he says.

Thanks for trying to help Kitedmon I appreciate it

[kitedemon]

Sorry it wasn't more useful. proping up the top strip might solve the problem but it is a guess, not knowing the exact cause would make me crazy (er) A second thought perhaps you will indulge me place a towel on the top of the rack and see if that changes the temps in the top shelf.

[mattchibi]

Sorry it wasn't more useful. proping up the top strip might solve the problem but it is a guess, not knowing the exact cause would make me crazy (er) A second thought perhaps you will indulge me place a towel on the top of the rack and see if that changes the temps in the top shelf.

Took your advice with the towel, we'll see how it goes.

I also added some aspen into one of the top tubs. It was reading 87-89 hot spot, and after 30 min with the little bit of aspen in there, the temps are now 92 at some points! but still around 88 on most of the hot side. The tub next to it, also on the top shelf, has no aspen inside, and is still reading 87-88, so maybe the aspen is helping keep the heat a bit better?

The towel might help too, but how would I insulate the bottom shelf? Put a towel under the entire rack? Would the towels be a fire hazard? I dont have a failsafe t-stat at the moment like you suggested to me in the past.