Reptile & Amphibian Forums

i built a new uro cage about a month ago and then this week built a top for it...i have screening on the top to sit the lights on (screening is actually on the undeside of the 2 x 4s used for the original top)...the cage has plexi-glass on the front and sides and wood on the back and bottom...have a door on the front for easy access...i felt that i was losing too much heat out of the top since it's just screened and also didn't love the way it looked with the light fixtures showing...i decided to build a top for the cage which was a piece of cake...it sits on top of the cage and i used hinges to make it easy to get to the lights...i drilled 3 holes in the back for power cords and thermometer sensors...well now it's holding the heat REALLY well, possibly too well...it hit me that i might now have too little air flow for my uros...I'm still playing around with the lighting/heating needs and how much i need to get it to approx 120 in basking area and then 80 on other side and ambient of approx 95 to 100 and high 70s at night...looks like 2 100 w basking bulbs will do it and then a 60 watt red bulb for night...Do i have enough air for my uros with the 3 holes in the top (actually the back of the top)? I was thinking maybe i should just drill maybe 5 or 6 1/2 inch holes in the back of the top? Opinions please..i'd attach a pic, but my digital cam isn't working (think i finally need a new one of those)...thanks!

Andy

My 4x2x1.5 cages have sixteen 1/2" holes on the top spaced between the floor joists of the next cage up for the purpose of venting heat (this also warms the floor of the next cage). You can always drill extra holes and cover them up until you hit your target temperature ranges. Unless your house is maintained at a constant temperature, you WILL find your equilibrium point changes throughout the year and a mechanism to cover/uncover vent holes as beneficial if you want to maintain a constant environment in the cages.

Relatively, I don't believe there's a lot of air exchange that is going to occur by diffusion through those holes. Convection currents should be causing hot air (used) to flow out of there, cool air (fresh) should be flowing in somewhere else (mine allows entry along the bottom of the doors).

In a neutral temperature environment your outflow will be equal and opposite to the inflow by volume, but in an cage getting warmer your outflow should exceed the inflow. As the cages cool off at night you should have a net inflow of fresh air as well, so there should be an oscillation in the atmosphere that is natural.

Depending on your door type, I expect that you might get the majority of air exchange when the cages are opened for daily feeding (rotating doors moreso than sliding).

Either way, I don't expect that there's a huge amount of oxygen uptake by even an athletic Uro. Humans easily handle oxygen levels 60% of normal levels.
-----
uromastyx geyri (Saharan/Nigerian), hardwickii (Indian),
macfadyeni (Somalian), ocellata (Sudanese), ornata (Ornate), benti pseudophilbyi

so if i understand, you're saying that i should go ahead and drill several holes in the cover - they will actually be in the back of the cover rather than the top...how do you cover them if you find you are losing too much heat? my house definately changes temps relative to the seasons and it's a constant battle with my fish tanks (too hot in the summer), tort enclosure (tough to keep warm in the winter) and the uro cage... my front door has hinges at the bottom and opens from the top...it's also not perfectly sealed, so i'm sure some air gets in that way in addition to when the door is opened...so once i put a few holes in the top, i should have adequate ventilation?

thanks!

Andy

>>so if i understand, you're saying that i should go ahead and
>>drill several holes in the cover - they will actually be in
>>the back of the cover rather than the top...how do you cover
>>them if you find you are losing too much heat?

Well, the back may be more challenging but still not a big deal. You don't need to seal the holes, just modify the flowrate through them. For mine all I need to do is slide a piece of scrap wood over them. If you drill on the back surface you might want to make a little L-shaped "pocket" that you could slide something similar into. I've found that tapes, like duct tapes, dry and the adhesives become quite brittle and wouldn't recommend them as a way to "permanently" change it.

>>my house definately changes temps relative to the seasons and
>>it's a constant battle with my fish tanks (too hot in the
>>summer), tort enclosure (tough to keep warm in the winter) and
>>the uro cage... my front door has hinges at the bottom and
>>opens from the top...it's also not perfectly sealed, so i'm
>>sure some air gets in that way in addition to when the door is
>>opened...so once i put a few holes in the top, i should have
>>adequate ventilation?

I don't see any problems with it. For the novelty, I've actually got an O2 sensor here and could do some rought "experiments" on a sleeping and woken Uros in sealed containers in addition to a regular cage and see what the O2 uptake is.
-----
uromastyx geyri (Saharan/Nigerian), hardwickii (Indian),
macfadyeni (Somalian), ocellata (Sudanese), ornata (Ornate), benti pseudophilbyi