Can more heat compensate for a poorly made night box?

[JokingYeti]

This fall we made an insulated night box but did not follow Tom’s design exactly.. we essentially made a bunch of insulated panels then attached all the panels together. I now see why Tom builds his the more difficult way. We have a 80w radiant heat panel with a Kane heat mat on an INKBIRD thermostat. We have been aiming for 83 degrees internal which it maintains until the morning lows get around 38-40 degrees. When the morning lows hit that range the internal box temp dips to around 77-78. I’m a bit worried as we will have temps down around 32 next week. My question is: can we add a bigger radiant heat panel to overcome the poorly made night box or do we need to start over? Or maybe a mini oil heater would be better? See attached pics for reference.

 

[ryan57]

This fall we made an insulated night box but did not follow Tom’s design exactly.. we essentially made a bunch of insulated panels then attached all the panels together. I now see why Tom builds his the more difficult way. We have a 80w radiant heat panel with a Kane heat mat on an INKBIRD thermostat. We have been aiming for 83 degrees internal which it maintains until the morning lows get around 38-40 degrees. When the morning lows hit that range the internal box temp dips to around 77-78. I’m a bit worried as we will have temps down around 32 next week. My question is: can we add a bigger radiant heat panel to overcome the poorly made night box or do we need to start over? Or maybe a mini oil heater would be better? See attached pics for reference.

Actually the core of your existing box looks good. Your temperature issue is because of thermal bridging. Wood is not a good insulator. You can do wonders for your box by adding another CONTINUOUS layer of 2" EPS insulation with Plywood then glued on top of it. Think of a foam cooler lined with plywood. That's what you're trying to do with an additional layer of protection so the tortoise can't destroy the insulation. Use Loctite PL3 construction adhesive and it won't/can't go anywhere. Just don't get it on your hands.

 

[JokingYeti]

Actually the core of your existing box looks good. Your temperature issue is because of thermal bridging. Wood is not a good insulator. You can do wonders for your box by adding another CONTINUOUS layer of 2" EPS insulation with Plywood then glued on top of it. Think of a foam cooler lined with plywood. That's what you're trying to do with an additional layer of protection so the tortoise can't destroy the insulation. Use Loctite PL3 construction adhesive and it won't/can't go anywhere. Just don't get it on your hands.

The walls are already filled with 1.5” foam board insulations. Are you saying I should do another layer?

 

[ryan57]

The walls are already filled with 1.5” foam board insulations. Are you saying I should do another layer?

Yes. Same as a modern house. Those 2x4's that you have flat and attached to both sides are transmitting the cold from the outside to the inside with almost NO insulation value. Insulation is about breaking thermal barriers AND preventing air flow. You've got the airflow thing down with the caulk, etc.

Notice the photos above: Every place in a house where the studs connect the sheathing(plywood or OSB) there is a thermal bridge from the outside to the inside.

In the case of insulating your nice spot that you've built you're kind of doing this in reverse. If you use 2" that tortoise will love you. Do the bottom, then do the sides. Then cut the plywood for the bottom and then cut the sides so the plywood meets at the floor. Then it will be basically a reinforced cooler and will keep all that good air in there. If the ceiling is air tight you will not lose very much heat through the top because that heats up first and holds temperature.

Look at how much wood is transferring the temperature outside to the inside because of the amount of wood used and the fact that it was used in a flat orientation. This is why the studs of your house are not flat.

 

[ryan57]

Yes. Same as a modern house. Those 2x4's that you have flat and attached to both sides are transmitting the cold from the outside to the inside with almost NO insulation value. Insulation is about breaking thermal barriers AND preventing air flow. You've got the airflow thing down with the caulk, etc.

Notice the photos above: Every place in a house where the studs connect the sheathing(plywood or OSB) there is a thermal bridge from the outside to the inside.

In the case of insulating your nice spot that you've built you're kind of doing this in reverse. If you use 2" that tortoise will love you. Do the bottom, then do the sides. Then cut the plywood for the bottom and then cut the sides so the plywood meets at the floor. Then it will be basically a reinforced cooler and will keep all that good air in there. If the ceiling is air tight you will not lose very much heat through the top because that heats up first and holds temperature.

Look at how much wood is transferring the temperature outside to the inside because of the amount of wood used and the fact that it was used in a flat orientation. This is why the studs of your house are not flat.

Even if you used 1" foam, tape and 1/4" plywood the thermal performance would be night and day different.

 

[JokingYeti]

Even if you used 1" foam, tape and 1/4" plywood the thermal performance would be night and day different.

I very much appreciate your insight. The graphics and thorough explanation really helped. Hopefully I can get this going tomorrow so we are ready for the colder temps next week.

 

[dd33]

Insulating it better would help but adding more heating capacity would be faster and easier. Not sure what the wattage is on the heat mat you have but you probably aren’t running much more than 200 or so watts of heat in there.
I would just add a small oil filled radiator heater on another thermostat and worry about perfecting the insulation when you have more time. Just make sure you don’t overload the circuit it is on. If it’s a 15 amp circuit you should try to keep it under 1300 watts total.

 

[wellington]

I agree with both however, dd33 has a cheaper and easier fix. However, an oil filled portable radiator heater can not be plugged into an extension cord. So if you do have to use an extension cord, then you can't use the radiator.

 

[ryan57]

Insulating it better would help but adding more heating capacity would be faster and easier. Not sure what the wattage is on the heat mat you have but you probably aren’t running much more than 200 or so watts of heat in there.
I would just add a small oil filled radiator heater on another thermostat and worry about perfecting the insulation when you have more time. Just make sure you don’t overload the circuit it is on. If it’s a 15 amp circuit you should try to keep it under 1300 watts total.

Yes. Faster, easier and more expensive to run.

 

[Maggie3fan]

Yes. Faster, easier and more expensive to run.

No not more expensive...I have a standard sized oil filled radiator heater in a 20'x12' insulated tortoise shed. The heater keeps the amnient temperature even on most freezing days at 85 degrees....it's about 2 feet of the floor making it safe from bigger Sulcata...the same heater has been in the tort shed for 16 years...so my point being if it's operating in my bigger shed cheaply it should work fine for you...

 

[Tom]

This fall we made an insulated night box but did not follow Tom’s design exactly.. we essentially made a bunch of insulated panels then attached all the panels together. I now see why Tom builds his the more difficult way. We have a 80w radiant heat panel with a Kane heat mat on an INKBIRD thermostat. We have been aiming for 83 degrees internal which it maintains until the morning lows get around 38-40 degrees. When the morning lows hit that range the internal box temp dips to around 77-78. I’m a bit worried as we will have temps down around 32 next week. My question is: can we add a bigger radiant heat panel to overcome the poorly made night box or do we need to start over? Or maybe a mini oil heater would be better? See attached pics for reference.

I think your design and build is sound. Here are the potential problems I see:
1. That is a big door opening. You are losing a lot of heat there. You can double up on the flaps to keep in more heat during the day. Its hard to tell from your pictures what is going on with your door. Is the door closed at night and also insulated like the rest of the house. Some of my early boxes did not have insulated doors. Most of the year in our climate, you can get away with it, but when night temps are dropping in to the 30s or lower, it made all the difference for me. You and I don't need it where we are for 10 months of every year, but those cold nights in December and January get us every time.
2. Is there weather stripping around the top where the lid rests? Very important detail. I get this type from Home Depot in 10 foot roll packages:

3. Ryan is not wrong about anything he said, but what he is recommending is just not necessary in our warm sunny climates. My opposition to adding a second insulation layer is that it would take up too much space in a box this size. dd33's suggestion of adding a mini radiant oil heater would also work, but I have the same space objection for that idea too in a 4x4 box, which is already reduced to around 40x40 inside with the walls and lid configuration. I do use the mini radiant oil heater in my 4x8 boxes, but they take up too much space in a 4x4 box.
4. I think your best solution is to add another radiant heat panel of the same size or larger, and a 27x36 inch 130 watt Kane mat would fit in there too. You won't need that much most of every year, but those items will get you through the occasional cold winter night safely. And also beef up the door, if needed.

@ryan57 I want to thank you for that explanation and sharing that knowledge. I am self taught and very ignorant when it comes to that sort of professional construction knowledge. What little I do know, I have figured out through trial and error. Lots of error. I greatly appreciate that sort of knowledge and I will incorporate that into future projects.

 

[JokingYeti]

I think your design and build is sound. Here are the potential problems I see:
1. That is a big door opening. You are losing a lot of heat there. You can double up on the flaps to keep in more heat during the day. Its hard to tell from your pictures what is going on with your door. Is the door closed at night and also insulated like the rest of the house. Some of my early boxes did not have insulated doors. Most of the year in our climate, you can get away with it, but when night temps are dropping in to the 30s or lower, it made all the difference for me. You and I don't need it where we are for 10 months of every year, but those cold nights in December and January get us every time.
2. Is there weather stripping around the top where the lid rests? Very important detail. I get this type from Home Depot in 10 foot roll packages:
View attachment 364887
3. Ryan is not wrong about anything he said, but what he is recommending is just not necessary in our warm sunny climates. My opposition to adding a second insulation layer is that it would take up too much space in a box this size. dd33's suggestion of adding a mini radiant oil heater would also work, but I have the same space objection for that idea too in a 4x4 box, which is already reduced to around 40x40 inside with the walls and lid configuration. I do use the mini radiant oil heater in my 4x8 boxes, but they take up too much space in a 4x4 box.
4. I think your best solution is to add another radiant heat panel of the same size or larger, and a 27x36 inch 130 watt Kane mat would fit in there too. You won't need that much most of every year, but those items will get you through the occasional cold winter night safely. And also beef up the door, if needed.

@ryan57 I want to thank you for that explanation and sharing that knowledge. I am self taught and very ignorant when it comes to that sort of professional construction knowledge. What little I do know, I have figured out through trial and error. Lots of error. I greatly appreciate that sort of knowledge and I will incorporate that into future projects.

1. The door opening is 16x24. I agree it is a weak point and am open to ideas for it. I currently have an additional insulated panel that fits inside the opening. The ramp then flips up and seals the door with weather stripping around the edges. I must admit it’s not a perfect seal but it’s not terrible either. Attaching a few pics for reference.
2. I am using 1.5” sponge type weather stripping along the top. It appears to have a good seal. I drew on the seal with crayola marker, then while it was still wet, I put the lid down, and watched for the color transfer from weather strip to the box lid.
3/4. Taking up space within the box was the immediate concern when I brought this all up to my wife so maybe you guys are on to something with that. I will hit a few reptile stores today and see if I can find a good RHP locally. Would you mount the RHP to the wall on the side we already have the heating units? So there is still a hot and cool side? Or should it go along the roof on the opposite side of the current one? If it is mounted on the roof next to the current one, i worry it would be very close to my thermostats temperature probe which could potentially mess up my readings?

 

[Tom]

1. The door opening is 16x24. I agree it is a weak point and am open to ideas for it. I currently have an additional insulated panel that fits inside the opening. The ramp then flips up and seals the door with weather stripping around the edges. I must admit it’s not a perfect seal but it’s not terrible either. Attaching a few pics for reference.
2. I am using 1.5” sponge type weather stripping along the top. It appears to have a good seal. I drew on the seal with crayola marker, then while it was still wet, I put the lid down, and watched for the color transfer from weather strip to the box lid.
3/4. Taking up space within the box was the immediate concern when I brought this all up to my wife so maybe you guys are on to something with that. I will hit a few reptile stores today and see if I can find a good RHP locally. Would you mount the RHP to the wall on the side we already have the heating units? So there is still a hot and cool side? Or should it go along the roof on the opposite side of the current one? If it is mounted on the roof next to the current one, i worry it would be very close to my thermostats temperature probe which could potentially mess up my readings?

I would try to mount the additional RHP on the ceiling over to one side over the heat mat. Just put the two of them side-by-side as far over as you can. I think the large Kane mat would help too.

Your thermostat's probe should be low down way over to the other side of the box, away from any heat source. You want the minimum temp way over there to be at least 80, and warmer on the side with the heating elements. Be sure the tortoise can't get tangled up in any wires. I use two hole pipe clamps going up the wall, or I cut some PVC pipe in half lengthwise, cover the wire and pipe clamp that to the wall to cover the cords.

This thread illustrates a good point. We make suggestions about what equipment has worked for us and what a person should use, but your thermometer should have the final say. Everyone needs to run their set ups, check temps, and make any adjustments needed. In your case, @JokingYeti , I think adding just a little more wattage and moving the thermostat's probe over will solve the problem. Moving the thermostat probe over might solve the problem without adding equipment. If the probe is close to the heat sources, it will shut off the heat too soon. I think your box is good to go.

 

[JokingYeti]

I would try to mount the additional RHP on the ceiling over to one side over the heat mat. Just put the two of them side-by-side as far over as you can. I think the large Kane mat would help too.

Your thermostat's probe should be low down way over to the other side of the box, away from any heat source. You want the minimum temp way over there to be at least 80, and warmer on the side with the heating elements. Be sure the tortoise can't get tangled up in any wires. I use two hole pipe clamps going up the wall, or I cut some PVC pipe in half lengthwise, cover the wire and pipe clamp that to the wall to cover the cords.

This thread illustrates a good point. We make suggestions about what equipment has worked for us and what a person should use, but your thermometer should have the final say. Everyone needs to run their set ups, check temps, and make any adjustments needed. In your case, @JokingYeti , I think adding just a little more wattage and moving the thermostat's probe over will solve the problem. Moving the thermostat probe over might solve the problem without adding equipment. If the probe is close to the heat sources, it will shut off the heat too soon. I think your box is good to go.

Thank you, Tom. My temp probe currently sits about two inches below the top of the door and about 4inches left of the center of the door. Aside from it being in the very actual corner that seemed like a decently cold spot and out of the way. I like your PVC and pipe clamp idea. That should be easy enough to implement. I will make a few adjustments and report back so future readers know the outcome.

 

[jaizei]

This fall we made an insulated night box but did not follow Tom’s design exactly.. we essentially made a bunch of insulated panels then attached all the panels together. I now see why Tom builds his the more difficult way. We have a 80w radiant heat panel with a Kane heat mat on an INKBIRD thermostat. We have been aiming for 83 degrees internal which it maintains until the morning lows get around 38-40 degrees. When the morning lows hit that range the internal box temp dips to around 77-78. I’m a bit worried as we will have temps down around 32 next week. My question is: can we add a bigger radiant heat panel to overcome the poorly made night box or do we need to start over? Or maybe a mini oil heater would be better? See attached pics for reference.

You had the right idea, it was just your first time. The error wasn't that you tried to build it out of panels, but how the panels were built.

 

[ryan57]

You had the right idea, it was just your first time. The error wasn't that you tried to build it out of panels, but how the panels were built.

It's funny: I built what I thought was a fine place to hang out but "Silver Spoons Stump" thought it sucked. It's not good unless he does it. I.E. a hole under a bush where I can't see him.

It wasn't until Figgy (the little 3" guy) chose to hang out in there that my outdoor house had purpose. The rate these things grow you'll have a chance to do over... at least when they're smaller.

 

[JokingYeti]

Insulating it better would help but adding more heating capacity would be faster and easier. Not sure what the wattage is on the heat mat you have but you probably aren’t running much more than 200 or so watts of heat in there.
I would just add a small oil filled radiator heater on another thermostat and worry about perfecting the insulation when you have more time. Just make sure you don’t overload the circuit it is on. If it’s a 15 amp circuit you should try to keep it under 1300 watts total.

dd33 was the winner. I ended up with a 400w oil filled radiator due to time and cost. It is doing great so far. Currently we have an outside temp of 30 degrees with an internal box temp of around 86.