# Question for HVAC people



## JPigg55 (Nov 26, 2012)

Hey everyone, new guy on the block.
Setting up my hobby shop and decided on using a 20' shipping container to do it in. Plenty of room for my small machines and very secure (think it would take nothing short of a torch to break in with the lock I got on it) given the location near the road away from the house where I decided to put it. Also wanted to stay away from tax burden of a permanent structure and considering moving so I can pick it up and take it with me.

Anyway, insulating the ceiling and walls (2X4 frame with R-11 fiberglass and 3/4" plywood), but not the floor. Figure 160 sq ft with 8' ceiling (actually small with space lost to framing), what size, brand(s), & voltage electric heater would you recommend ???
Wanting thermostat control with forced air as well.
So any advice on voltage (110/220), BTU output, etc would be appriciated.


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## pjf134 (Nov 27, 2012)

One thing to be aware of is that a shipping container like on ships are sealed tight so it would be a good idea to provide some outside air once in awhile so you can breathe if you spend a long time in there. If heat is off most of the time and only want to use it in the evening you will need a bigger heater or use a smaller heater turned on say a hour before you go in to use it. Infra-red heater are best because they heat objects instead of air and will get machines up and running quicker. You could use a timer on a small heater to come on before you go out because it will take awhile to heat things up when cold if that's your plan. It all comes down to how fast you want it to heat up and does your area get to -20 F often, if so it will take more of a heater to work.
Paul


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## OldMachinist (Nov 27, 2012)

It shouldn't take more than one of those 1500 watt utility milkhouse heater to keep it warm. I have a 10' x 24' insulated shed that is used for exercise equipment and that all I use.




While you're framing it out you may want to cut a opening for a small window air conditioner. Those shipping containers can get pretty warm in the summer.


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## jgedde (Nov 27, 2012)

Search the net for "manual J calculator" which will yield the required BTU for your setup based on info you enter. Here's an example: http://www.mrhvac.com/free-hvac-stuff/free-heat-gain-and-loss-calculator/

Since ventilation could be an issue, I'd stay electric. Whether you need 110 or 220V will come out of what your BTU needs are...

John


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## Al 1 (Nov 27, 2012)

Please do yourself a favor and incorporate another egress area toward opposite end of your entrance door. This can be a door with a push bar, a egress window, etc.
 Al 1


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## JPigg55 (Nov 27, 2012)

Thanks for the info.
Container has vents in all four corners that I plan on installing a vent fan and duct on for fresh air and fumes. Also am framing the door end wall on hinges to be able to fully open.
Thought about windows, but can't see a good way to seal since the sides are corrigated and would make for easier access if someone wanted to break in. I'm out in the sticks on a small farm and the shop will be out of view of the house about 500 feet away next to the road.
Thanks again,
JP


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## JPigg55 (Nov 27, 2012)

BTW:
I'm in west central Illinois so the winters do get cold.
I figured a small electric heater would be the best way to go, but would also like to have some sort of temperature control that I could have turned down when not in use and could turn up an hour or so before working in there if needed.
I do have an integrated 110v thermostat cord that I inherited with the farm, but will have to check to see if wire gauge will work with the heater current load or not. I just haven't seen any 110v electric heaters that were rated worth a hang yet.


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## Ray C (Nov 27, 2012)

I have a feeling electric will be the way to go especially if you're running it while unattended.  To warm it up in there you'll need about 10,000 BTUs which is the equivalent of about a 3000 Watt electrical load which, is a 25 amp circuit.   You're going to need more than an extension cord -that's for sure.  Having lived in Chicago most my life, I know you'll get some colder weather.  At times, you'll probably want more than 10k BTU.

In my garage, I just switched to this unit which is 20,000 BTU dual fuel (propane or natural gas) that has a 5 setting thermostat.  I like it a lot and it's much better than the kerosene unit I had for the last 7-8 years.  Anyhow, right now I'm running off propane until I run a gas line in the spring.  I'm using 60lb tanks that cost 60 bucks to fill.  It's 99.5% efficient and rated for enclosed indoor use.  It runs for 3-4 weeks straight, keeping the insulated garage at 62 degrees but, our winters are milder here. The garage has 655 sqft floor space with 9ft ceilings.  If you go the route of a gas unit, do like I do and install smoke and carbon monoxide detectors.  That's 20 bucks of cheap insurance.  My garage has plenty of air cracks and when I'm in there, I crack the overhead door a quarter inch.  I've never had a problem with kero or so far, with this gas unit.  The gas unit beats the pants off the kero unit.  No smell at all.

Anyhow, if you want to keep the chill out of there when you're not inside, you could get a 1500 Watt oil-filled room heater and set it on low.  They're pretty safe but like anything, keep a watchful eye for hazards.  When you occupy the space, you could put extra electric units in there assuming you've got adequate power.

EDIT:  BTW, meet Sasha.  She's my constant companion and shop manager.



JPigg55 said:


> BTW:
> I'm in west central Illinois so the winters do get cold.
> I figured a small electric heater would be the best way to go, but would also like to have some sort of temperature control that I could have turned down when not in use and could turn up an hour or so before working in there if needed.
> I do have an integrated 110v thermostat cord that I inherited with the farm, but will have to check to see if wire gauge will work with the heater current load or not. I just haven't seen any 110v electric heaters that were rated worth a hang yet.


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## Ray C (Nov 27, 2012)

Oh, heres a link to the oil filled units I'm talking about.  They work well but take a long time to warm a space.  I used 2 of them in the early days of setting up the shop.  I guess you'd call that PK (pre-kerosene).    Also, it helps to get a small oscillating fan to blow the heat around.  I still do that till this day.

http://www.meijer.com/s/pelonis-oil...eijer_eCom_PLA_Home_Improvement&kpid=NY15EC-7


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## Tony Wells (Nov 27, 2012)

I wish your closer. I would probably give you a sweet deal on one of these:




I have one hanging in the shop, but I haven't used it since I put in the central heat/air.


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## JPigg55 (Nov 28, 2012)

Thanks Ray C, room wise, I was more looking at for one I could mount/hang from ceiling or walls.
BTU info sure helps though.


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## pjf134 (Nov 29, 2012)

One thing to be aware of is voltage drop at 500 ft. from house. Some halogen lights will give off heat also while in the unit along with a small electric heater for main heat. If you plan on running machines, heaters, fans, lights ect. that would add to the power requirment and should need a larger gauge wire. You would always be adding to the electric in the future so keep that in mine when buying wire. Moving the container closer to the house would be cheaper and save you from walking 500 ft. thru 2 ft. of snow while it is -20 below. Figure out what amps you require for each device and double that to get to the size of wire required. Just my 2 cents worth.
Paul


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## Tony Wells (Nov 29, 2012)

500 feet is a long way to run enough power for even small machines. Get ready for sticker shock when you price the required size cabling. 100 amp service 500 feet will require 4/0 wire...... 3 runs and a ground. Found some online for $4.62/ft plus freight, which will be considerable. Local source likely would be better, even if per foot price is higher. Probably be cheaper to get the power company to hang another pig if you're near the line.


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## JPigg55 (Nov 29, 2012)

Thanks for the warning, but I'm hooked in to a meter service about 5 feet away. Had to keep the old service live for power to old barn and sheds.
They're in bad shape and needed rewired so just disconnected and ran new to my shop container. I would have had to rewire the house service for room and figured since I had the other service anyway in a location that was more ideal for my shop.


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## Rbeckett (Nov 29, 2012)

JP,
We converted quite a few of those while I was deployed in Iraq.  We used regular 2x4 for framing and covered them with plywood.  we dropped back a bit from the container door and installed a regular house door on the right side with a window heat pump on the left.  When the doors on the container were closed it was invisible and safe from tampering.  When you opened the container doors you had a regular door like on a tool room.  The amount you drop back from the container doors is set by the depth of the window unit.  All power in Iraq was 220, 50 hz so  we had 220 lites and the unit was 220 also.  Made a great office in the heat and cold of the desert so the US should be simpler and require less BTU's of heat and cool too.  Hope this helps.
Bob


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## Ray C (Nov 29, 2012)

BTW:  I'm guessing that for the size space you're talking about 15,000 BTU would be OK but, most smaller heaters come in 5, 10, 20 and 30,000 BTU.  For some reason, 15,000 is not that common.  I just got through looking all this up.  Also, the heater I have (as mentioned before) keeps the garage at 62 on it's lowest setting.  Next notch pushes up to about 72 degrees.  Finally, I'm not a big fan of the IR (infrared) types and prefer the blue-flame.  They are no more or less efficient but tend to toast you on one side and leave the other side cold as the dark side of the moon.  My buddy got the IR type and regrets it for that reason.

Ray


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## jpfabricator (Nov 29, 2012)

Tony Wells said:


> I wish your closer. I would probably give you a sweet deal on one of these:
> 
> 
> 
> ...



Tony, Is this unit gas, or electric?


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## Terrywerm (Nov 30, 2012)

Quite a few years ago I worked for a company that bought old shipping containers and refurbished them to use as rental storage units. We also did quite a few as portable worksite storage and office units. As you found, these units are vented on each corner, but it is minimal ventilation and was in place to prevent moisture problems inside the containers.

We used to cut in windows and doors all the time. We would cut out the opening, then make a frame from rectangular tubing welded to the corrugated sides. Then the doors and/or windows were attached to those fabricated frames. Barred windows were a standard item, and doors were always steel and were set to open OUT. A secondary sliding door made of heavy bar could be closed over the outside of the entry door, and the padlock was inside a pocket where the hasp could not be cut, much like "Job box" tool storage boxes. The beauty of this arrangement is that (1) a door that opens out cannot be kicked in, (2) space inside the unit did not need to be wasted to allow room for the door to swing in, and (3) the sliding security door was built heavily enough that it was NOT coming off. 

Most job office units were forty footers, split into a 20 foot office and a 20 foot storage area, separated by a steel wall that was welded in. The rear end with the doors was obviously the storage end. The office door and window(s) were added on the sides only, because the hookups for power and phone were on what had been the front of the container, along with a heat and A/C wall unit similar to those used in many motels. Units that had heat but no A/C used electric baseboard heat instead of a wall unit. Walls and ceiling were framed out with 2x2 studs in most cases, though some had 4" thick walls, styrofoam insulation, and white plastic crinkle finish paneling.  Floors were also framed out and insulated the same way, but with 3/4" plywood added as a subfloor on top, covered with plain old linoleum flooring. Modern practice is to use self expanding urethane foam for insulation so that moisture cannot get to the steel walls, as they would be completely sealed off by the urethane. Breaker panels, outlets, switches, and lighting are all wired and installed prior to the insulation being installed. 

Extra ventilation was not added to those containers, as job site offices were generally not "heavily populated" and the door opened and closed frequently throughout the day, providing some fresh air each time it opened. In your case you might want to add some form of forced ventilation that can be turned on as needed, as there are many opportunities to create noxious fumes in a shop environment.

I realize that you probably have your plans pretty well set already, but thought that I would add my two cents worth based on what we used to do for commercial use on rental units, knowing that you might find some tidbits useful. We did make one big mistake with our first office container though. When welding in the new door frame, we forgot to allow for the thickness of the new raised floor that was going to be installed, and we had to cut it all out and cut the opening 2" taller and put in a 2" filler bar at the bottom of the opening. It was relatively easy to fix, but we were kicking ourselves for overlooking something so obvious. Thankfully we discovered our error prior to painting the container, which was normally done after all of the welding was completed, but before any interior work was begun.

I wish you luck with your project, you should find that the container will work well for your purposes.


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## Tony Wells (Nov 30, 2012)

jpfabricator said:


> Tony, Is this unit gas, or electric?



It's electric, 220/240 Single phase.


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