1. Home
  2. Hobby Electronics Basics
  3. It worked !!!

It worked !!!

My shop is a steel building similar to a quonset hut. The pipes to my bathroom sink run down inside one of the deep corrugations. The bathroom walls are covered in drywall which in turn is covered with thin sheets of vinyl covered Masonite. I insulated the pipes before covering them with the drywall. I then put insulation down inside the corrugations to insulate the walls. But I think some rodents got into the insulation. Whatever happened when the temp drops below about 30 degrees the bathroom pipes will freeze. I am not eager to tear into the wall to find the problem. So I leave the taps slightly dripping when the weather gets too cold. I now have a little water heater under the sink so that the main water heater is off most of the time. I turn off the under sink heater when the tap is dripping. So my system works except when I forget to leave the water dripping. And I did that yesterday. Coming in to work this morning I discovered the frozen pipe problem. Besides the hassle of no water one day the pipes are going to burst and then I WILL need to tear into the wall. But maybe I have hit on a solution. The water pipes going into the main water heater are connected to each other with a heavy copper wire just before the heater connections. This is to comply with the building code. So I figured if I connected some power to the pipes right at the wall stops I could maybe get them to heat up enough to thaw them. I measured the resistance from stop to stop and it was 4 ohms. The stops are plumbed to the sink taps with plastic pipe so I know the resistance I measured was through the supply pipes. So I plugged in a Variac, plugged my battery charger into the Variac, and connected the battery charger leads to the wall stops. Then I dialed up the voltage until the charger was putting out about

18 amps. Checking about an hour later I see water is now flowing from the taps. So now I need to wire up a transformer controlled by a thermostat to keep those in wall pipes warm. No more dripping taps! Anybody want to tell me why this is a bad idea? Thanks, Eric
Reply to
etpm
Loading thread data ...

Are you in Massa2shits ?>:-} ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| STV, Queen Creek, AZ 85142    Skype: skypeanalog |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 
              
     It's what you learn, after you know it all, that counts.
Reply to
Jim Thompson

Washington State. Why? Eric

Reply to
etpm

Call your local government agency in charge of building codes. Ask them if what you want to do is legal ;-) ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| STV, Queen Creek, AZ 85142    Skype: skypeanalog |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 
              
     It's what you learn, after you know it all, that counts.
Reply to
Jim Thompson

What you want is pipe heating tape...

...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| STV, Queen Creek, AZ 85142    Skype: skypeanalog |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 
              
     It's what you learn, after you know it all, that counts.
Reply to
Jim Thompson

Had you the forethought to use heat tape that would have been the better solution. If you can get in around the pipes where they enter and leave the wall it may be possible to put enough tape in a spiral around the pipe. (providing there's no clamps or insulation in the way and not too many bends)

How about a sheet of insulation on the outside of the building and another layer of galvanized metal?

If you're dealing with galvanized iron pipe, you can't count on the resistance staying constant because threads rust and rust insulates. With DC voltage you're probably going to destroy the piping with galvanic corrosion.

It may work, but chances are it will fail and may do so catastrophically. As a infrequent thing it may be OK but when you start talking about thermostats etc., I'd back off and find a safer way.

Reply to
default

Yes they did that in the olde times when they used metal pipes throughout. Today we have plastic pipes.

w.

Reply to
Helmut Wabnig

At one home I had built, I put a return pipe on the kitchen sink hot water pipe. The return went back to the bottom of the water heater. Hot water would rise to the kitchen sink and cooler water dropped back to the bottom of the water heater. So I always has immediate hot water at the kitchen sink. I don't know if you have access to connect something like that. But it was nice while we had it. It's a little wasteful, but I suspect I spend more dumping water down the drain waiting for hot water.

Hey, How about a small thermostatically controlled pump between the hot and cold pipes under the sink. Pump hot water into the cold water pipe whenever the temp is below freezing and maybe a 5 minute turn off switch for when you want cold water but the temp is below freezing. Would take much of a flow rate. Mikek

Reply to
amdx

You know Mike, reading your post reminded me of a thermostatically valve made just for turning on the water to prevent pipes from freezing. They start flowing water at about 34 degrees as I recall. Anyway, I bet if I remove the wall stops, connect the valves to the plumbing, and then reconnect the wall stops to the valves my problem will be solved. I think the cooling pipes will cool the thermo valve and make it work. I need to research these valves. Thanks for the reminder. Eric

Reply to
etpm

hot water pipe. The return went back to the bottom of the water heater. Hot water would rise to the kitchen sink and cooler water dropped back to the bottom of the water heater. So I always has immediate hot water at the kitchen sink"

I just saw something like that on This Old House.

Old my (_|_).

Reply to
jurb6006

a question very well posed.

using AC to warm the pipes is probably better than using DC from a charger (which may increase corrosion at the positive end)

18A into 4ohms is about 1300W which seems possibly excessive, fire risk perhaps?

It's also 72V and voltages much lower than that have proven fatal to people with wet hands - Do you think there's a risk that someone with wet hands might come in contact with that?

--
This email has not been checked by half-arsed antivirus software
Reply to
Jasen Betts

I did that around 1992., I don't know where I saw it, I didn't have internet then. Mikek

Reply to
amdx

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.