I would like to heat an area (128cf with no moving air) using a 1500W heat lamp(s). I would also like to control the temp. inside this space with a standard home T-stat. mounted inside the area being heated. I understand the T-stat uses 24v while the heat source is 120v. I would also like to add a small fan (the kind you would find in a computer. Not sure if these are 120v or stepped down) to move the air around just enough so as not to have any hot spots in the area being heated. What would be the best way to wire in a T-stat, heat lamp, fan and transformer ? (the type used in a home furnace)

This could get messy. You would need a transformer, the thermostat, and a relay to control the power to the lamp. All the 120 volt connections would need to be in an electrical box. Then you would need a separate power supply for it if you used a 12 volt computer fan. You could make up a box with a power cord, a duplex outlet, and the relay inside. The transformer might better go on the outside with its leads go in in through a bushing. Wire the relay to control the outlet and plug the lamp and fan power supply into it. It certainly wouldn't hurt to plug the whole works into a GFCI outlet, and maybe required if there is any water in the space.

You might better look around a pet supply or even a garden supply for a thermostat and fan made for 120 volts. Even a baseboard heater thermostat might work. Make sure everything you use is rated to handle the 1500 watts or the total of what ever you find you need.

Study the project and post back if you need more details.

I think you may be on to something with using a 120V baseboard heater T-stat. (I happen to have one) How would this be wired in conjunction with a small 120V fan and heat lamp? The T-stat I have from a baseboard heater is rated 120V and 22A single pole (Red and white wire)

Should work. Use a 3 wire cord heavy enough to carry the load, not the regular 18 gauge. Connect the black to the black of thermostat, and the red to the brass screws of an outlet. Connect the white from the cord to the nickel plated screw of the outlet. Mount the thermostat and outlet on a box and connect the green wire to the green screw, and the metal housing of the thermostat, and box if metal. Then you can just plug the light and fan in the outlet. Or just hardwire everything.

Bad idea after you spend the money to make it work and it not being safe you can buy a small portable heater from a store that is safe. A fan on a home PC is 12 volt ac.

T-Top... Won't work. All the heaters on the market have a built in safety disconnect. When the temp. hits 90' the heater shuts down. This is caused by no cooler air passing by. (the area being heated is only 8'x8'x2' hi.) The heater senses it is getting too hot and shuts down before it completes the task I want to obtain and that is heat a ceramic floor above the area being heated. I figure I have to heat the area (box) under the floor to around 100' for a period yet to be determined, enough heat to transfer to the floor above. I'm not worried about fire as wood has a flash point of 572'. The interior of the area being heated is lined with reflective insulation. I have an industrial timer wired in (outside the box) to turn the heat off and on twice a day for the time it takes to warm the ceramic floor. (this has yet to be determined) I have tried the heater approach but the heater shut down before the desired effect. The heater experts tell me that I would have to by pass the built in safety shut off to do what I want. That could cause a problem with over heating and fire. I figured a 1500 Watt heat bulb(s) turned on for a given time would heat the area and not have the problem I am having with the heater. I want a small fan only to move the air around in the area enough so I have no hot spots. Thanks for your input!

With a little care, I think you can do this safely. I wonder with a wide, flat space if one or 2 bulbs is going to work very well. The heat lamps heat what they shine on. With the bulb only 2' away, the light won't spread much, leaving where it hits hotter than the rest. Many smaller lights might work better.

Although it sounds to me like what you want may be able to be done safely, I have learned enough in the E&L forum to realize it may violate code. I think it is time to call in our electrician. As I said at the beginning, this could get messy.

Labman, your probably right in regard to the code issue, however, I feel that the idea is sound and safe or I wound not risk a six hundred thousand dollar house. The only item in the enclosure is the open floor above which would need open flame and or have to reach a 572' heat source. The power (120V) goes into a mechanical industrial timer. From the timer it will feed my heat source. I felt that by using heat bulb or lights would heat the air which in turn would transfer through the floor which in turn would warm the ceramic tile. I only added the fan because I believe the lights would create a hot spot above them. Moving the air should prevent this. I was going to start by using a 1500W heat bulb in a ceramic light base. The fan would come on at the same time. I would then experiment with how long the light needs to stay on in order to warm the floor. If I found that in one hour the floor was not warm I could increase the time. If I still can't warm the floor enough I would introduce a second light. Since the floor is in a bathroom I only need the floor warm when I get up (about 7am) and when I go to bed (about 10pm). I was figuring that the light would need to come on about one hour before I use the bathroom and the same amount of time at night. I don't want to add too much heat to warm the floor more quick than one hour as I feel it could do more harm than good. It will be a trial of time and of possible adding more lights. I know this sounds like a lot of work but I have already built the box under the floor (took about five hours) and run the wiring. When I had the 48' addition added to the house I was stupid not to have in floor (electric matt) heat installed at that time. To add hot water heat under the floor now would cost quit a bit as not only would I have to run all the tubing but I would have to purchase a pump to add into my hot water system to add hot water to heat the floor. I thought this would be a quick fix.

Look at it this way, can you hold your hand on a 100w bulb for 10 sec. with out getting burnt. What happens when dust or a mouse or wood gets on the lamp with no heat safety. What do you think the insurance company would say. If it was a good way to heat,safe and efficient we all would be doing it.

Let me jump in here with a few comments and observations, if I may:

Quote:

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Originally Posted by Dcbradys

T-Top... Won't work. All the heaters on the market have a built in safety disconnect. When the temp. hits 90' the heater shuts down.

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Now why do you think any heater on the market has a high temperature safety limit switch?

Quote:

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Originally Posted by Dcbradys

I was going to start by using a 1500W heat bulb in a ceramic light base.

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I am not aware of any 1500 watt heat lamp that would thread into a standard medium base lamp socket. Any ceramic medium base lamp socket available is only rated to handle 250-300 watts at the maximum.

The only 1500 watt lamp I am aware of is a quartz halogen, and the wall temperature of the bulb will exceed 450 Deg F. Any of these 1500 watt quartz halogen lamps are tubular shaped and use a double ended socket and need their own special fixture.

So, can you please let us know what the make and model number of the heat lamp you plan to use?

I have attached some product technical data on quartz halogen lamps:
From Phillips Lighting:
Notes

* WARNING: BULB OPERATES AT VERY HIGH TEMPERATURES AND MUST BE USED PROPERLY TO AVOID/REDUCE RISK OF FIRE. Do not use bulbs greater than 300 watts in indoor residential fixtures. Use only in fixtures specifying this bulb type and that meet revised UL 153 standard for tungsten-halogen torchiere lamps. Bulb is pressurized and could shatter and should be used in fixtures that provide a protective shield of tempered glass. To avoid exposure to ultraviolet radiation which could cause skin and eye irritation use only in fixtures that provide a protective shield of tempered glass. NOTICE: Do not touch bulb with bare hands. Fingerprints may result in reduced performance unless they are removed with alcohol. When operating bulb is hot. To avoid risks of burns or injury, turn power off and allow bulb to cool before replacing. Socket conditions may affect bulb life. Inspect and replace socket if deterioration has occurred. Provide adequate ventilation to ensure that seal temperature does not exceed 300 degrees C. TO AVOID/REDUCE RISK OF FIRE, DO NOT USE NEAR COMBUSTIBLE MATERIALS. (99)

Note the 300 watt maximum bulb allowed in residential in the paragraph above, and the comment "do not use near combustible materials".


Any 1500 watt load, whether a lamp or a heater, will draw 12.5 amps at 120 volts. This 1500 watt load will be fine for a 15 amp circuit.Your plan is to add 1500 watt heat source if one is not sufficient. This will increase the load to 25 amps. Now a 30 amp circuit with #10 wire is needed. So if the unit is wired with a 15 or 20 amp circuit, adding another 1500 watt unit will overload the circuit, and need to be rewired.

My understanding is that an enclosed box has been built under the bathroom floor, and the intention is to flood this space with heat, and the heat rise to warm the wood floor to ultimately warm the ceramic floor.

Wood has a very low value of heat transfer conductivity. Do a web search for "thermal conductivity of wood", to see all the info on this topic. The air in the space below the wood floor would need to be very high to cause the wood to heat up enough to transfer that heat to the ceramic floor.

For so many reasons I just don't see your proposed plan to heat the floor underneath with heat lamps working as expected, and if not careful with the temperature of the heat source, the proximity of the heat source to the wood, and the electrical issues, may be causing more problems than anticipated.

Quote:

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Originally Posted by Dcbradys

heat a ceramic floor above the area being heated.

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Simple Question time:

Have you considered Radiant Heat Systems?

Examples:
Green Star Radiant Systems: System Types- Hydronic In-Floor Heat

I think the bottom two optioins are what would work best for you. (I know we just bridged the gap to plumbing). With the advent of PEX plumbing products, you could do this yourself.


If you have to stay electric, you can always rip up the ceramic tile and relay it with electric radiant heat blankets laid into the floor.
Example:
Nuheat: The leading radiant electric floor heating system manufacturer. Under floor heat for a warm floor.

I'd imagine what money you'd spend in startup costs, would be offset by
1. The cost to run
2. You have a usable space in your house. (The room would be normal again)

All this is noted. I will contact the heat lamp people and tell them to stop selling this appliance, it's unsafe. I will also contact the home insulation people and let them know that a home would have to be heated much to warm for heat to transfer outside so they should stop fooling their customers for placing insulation in their homes. Thanks guys!

Not really sure how to take your comments. Seems your not open to advice, even thou advice was requested and there was some concern about the safety of such an assembly. Everyone here is only trying to help.

I did ask "can you please let us know what the make and model number of the heat lamp you plan to use?"

All you mentioned was a heat lamp, never mentioned an appliance, until your last post. If there is something available, please share your knowledge so that maybe someone else can benefit by it.

Not sure what you mean by the home insulation people.

Sorry you did not hear what you wanted.

The more posts I read, the less it seems like a good way to heat the floor. Just because you can do it, doesn't mean it is a good idea. I wonder about a single recessed light in the center of the ceiling on a timer. Turn it on, 4 AM whatever it takes to have the floor cozy and warm and the light off when you get up. Even a 150 watt bulb might do and still be within the capacity of your existing 14 gage circuit. Tkrussel can address if it needs to be GFCI, but likely the lighting already is.

I'm like tkrussell not sure how to take your comments. Good luck with your project. mpking said it all (HYDRONIC HEATING).