24volt vs 115volt zone valves and thermostats

CoalUserWannabe wrote:

coaledsweat wrote:The 24 volt allows for it to run more devices.

Does that mean I can not turn on all my 110 Volts lights at home at the same time ?

No, it has nothing to do with your 110 system in the house. What it means is you can typically operate more zones and valves without getting more involved in money and parts to do a 24V control system than you could with a 110V control system.

CoalUserWannabe wrote:There are too many drunks answering, I thought I was bad !

No drunks here, just someone offering their thoughts and trying to be polite at the same time. Maybe you could do the same?

Thanks for the electrical seminar, but I fail to see how it applies to a low-budget control setup with very little "current". My little system has six zones controlled with a $10 24V transformer, some 20 gauge thermostat wire, two reclaimed R845 relays, and some el-cheapo Honeywell thermostats. The rooms stay within +/-0.5 degrees of setpoint and I've never had to replace a single component. Works for me...your mileage may vary.

Rob R. wrote:No drunks here, just someone offering their thoughts and trying to be polite at the same time. Maybe you could do the same?

Exactly my point, all of us drunk , offer and share more than any sober man can:
few weeks ago, a buddy of mine was depressed because his "Beautiful " girlfriend dumped him, so to cheer him up , I told him he can have my hottie for the night, he had the nerve to tell me she was not pretty enough, and I said " Hey , have few more beers, she 'll look real HOT "

Anyway, by the time she started looking pretty in his eyes, they were almost closed , he couldn't walk straight, and we had to give him a ride to his place.

I 'll never make an offer like that to anyone, just imagine how ungreatfull people could be !

On the technical note back at the Ranch:
if you have your 24 volts system already setup with bunch of extra 24 volts devices around, by all mean go ahead and use 24 volts stuff, but if you are starting from scratch, you have to look at the entire picture !

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steamup wrote:ah, what you have is a convector. (Coil in a box).

If the piping is in parallel with a pumped zone, and you want to keep it simple, buy a self contained thermostatic zone valve. One with a remote sensing bulb would be better.
Mount it in the piping in the convector box .
No wiring involved.

They work ok if applied correctly.

http://www.pexsupply.com/Honeywell-Ther ... es-1524000

Steamup,

I should have used the correct term. Yes, simple wall mounted cabinet, apx 60" wide, 24" tall, open bottom, louvers in front near the top. It has a three tube single pass coil, 8" wide full length, lays flat. I fashioned a full length manual damper between it and the louvers, but it still allows too much heat past it for it to effectively function as a temperature regulator for the garage.

Thanks much for the link. I'm a tinner, and have worked around plumbers for 30 years, but I didn't know that they made such a valve. It looks to me that such a device would work fine for my needs. The sensor with the remote bulb looks really nice.

Dave

24 volt controls are used tow two reasons, one being safety (24 volts won't kill you) and a 115 volt thermostat will pick up heat from the current flow and falsely heat the thermostat (called thermostat droop) which will worsen as the equipment runs more often. the colder it gets, the worse the "droop" gets.

For a garage I doubt it makes much difference and the post above suggesting using a self powered zone valve is likely the best answer. Simple is good..

Ops

The voltage doesn't kill, but the amps. 50 milli amps( devide 1 amp into 1 MILLION, 50 out of 1 million) can stop the heart. I searched and one sight clamed a 9 volt battery has the potential to stop the heart.

AA130FIREMAN wrote:The voltage doesn't kill, but the amps. 50 milli amps( devide 1 amp into 1 MILLION, 50 out of 1 million) can stop the heart. I searched and one sight clamed a 9 volt battery has the potential to stop the heart.

30 millivolts and 30 milliamps applied to the heart directly will stop it. the idea of 24 volts is that lower voltage is less likely to push 30 milliamps into your gizzard than 120V, just like 240V is more likely to kill you than 120V.

Ops

Ops164 wrote:

AA130FIREMAN wrote:The voltage doesn't kill, but the amps. 50 milli amps( devide 1 amp into 1 MILLION, 50 out of 1 million) can stop the heart. I searched and one sight clamed a 9 volt battery has the potential to stop the heart.

30 millivolts and 30 milliamps applied to the heart directly will stop it. the idea of 24 volts is that lower voltage is less likely to push 30 milliamps into your gizzard than 120V, just like 240V is more likely to kill you than 120V.

Ops

I agree, but I just wanted to put the possability out there. There was an electrician that died at my work last summer, no cause of death found by an autopsy, changing a light fixture, wire nuts on the wires, I believe 208 3 phase, no entry burn marks in or out,OSHA did an investigation, someone saw a flash, he was on a high lift, unresponsive, and cpr was done . GOD bless him, real nice man to work with, I DO MISS HIM.

http://en.wikipedia.org/w/index.php?tit ... ion=submit
http://wiki.xtronics.com/index.php/Wire-Gauge_Ampacity
http://www.constructiongear.com/carolin ... 4AodXRhNtQ
http://www.envirosafetyproducts.com/rub ... -volt.html

P=I^2*R
With current being 1-1.5amps, 24v will require a 16ohm resistor and consume 36 watts.
With current being 1.5amps, 110v will require a 73.33 ohm resistor and consume 165 watts.

Heat Dissipation
The heat dissipation of a 73.33 ohm resistor will be much greater than a 16ohm resistor and in a thermostat that may lead to a greater temperature sensing inadequacies.

Voltage drop
With equal length and equal amps the voltage drop is 73.33/16 is 4.5x greater in the 110v circuit.

VD = 2*L*R*I/1000

To make up for voltage drop you go up in wire size (V=I*R). In power distribution over very long distances and larger amps this becomes cost prohibitive thus increased voltages.

A big thanks to steamup.

I went with these parts. Easy install, cheap, plenty good for a garage imo.

http://www.pexsupply.com/Honeywell-T100 ... tor-Valves

http://www.pexsupply.com/Honeywell-V200 ... ator-Valve

Dave

Valve and controller work quite well. Temp in garage pretty consistant

Don't you love it when a "KISS" works.

steamup wrote:Don't you love it when a "KISS" works.