Advice Needed to install car radiator to hot water tank

[alltoys]

I plan on hooking up a car radiator to a hot water tank then a 110V fan on the other side to blow air through the vanes. I have a small hot water tank for this purpose just waiting to be used for this little project. I have seen it before with respect to a hot water floor heat system in a garage for instant heat after the large door has been opened.

If anyone can tell me what I need to do this besides the radiator thank you for your input.

 

[Tig]

I think if you feed the top of the tank to the top of the rad and then the bottom of the tank to the bottom of the rad you should get circulation by thermo-suction. The fan should increase the flow as it will cool the water more rapidly so that it flows down and returns to the tank more quickly.

 

[johnk]

I plan on hooking up a car radiator to a hot water tank then a 110V fan on the other side to blow air through the vanes. I have a small hot water tank for this purpose just waiting to be used for this little project. I have seen it before with respect to a hot water floor heat system in a garage for instant heat after the large door has been opened.

If anyone can tell me what I need to do this besides the radiator thank you for your input.

I know radiators are set to relieve at no more than 12 pounds so I'd be a little afraid of putting 60 pounds water pressure through it. I really don't know the bursting strength of a radiator so that would be the first issue..

 

[Treemonkey1000]

Just thinking out loud. Wouldn't pulling all of that heat out of your water tank cost you more in the long run? 2nd thought about being over pressured for the water tank. You could restrict the pressure with a simple faucet valve to feed the radiator. Feeding it back into the system it might have a lot of lead or crud from the radiator. Maybe a closed loop system where you just heat a tank of water and circulate it into the radiator.
Another method is fabricate yourself either a copper grid to hold the water pressure and blow the fan through it. Or even the new high temp and pressure pex pipe could handle the pressure. You would be introducing less contamination into the water system that way.

 

[Tig]

Plumbing this to your drinking water would be a bad idea for the pressure and contamination reasons mentioned above. A system like this should stand alone and be filled via the rad cap. You should also turn the tank temp way down. It would make it safer.

 

[DavidVT]

I have seen this done with hot water from an outdoor boiler setup.
In his garage, a friend plumbed an old bulldozer radiator to the water loop and made a nice modine style heater by putting an AC fan behind it. It was a great conversation piece and worked well.

In this config the loop was never pressurized and the water was not part of the domestic drinking water. He had one loop off the boiler to the house and this one to his garage.

 

[ampsucker]

not sure this is making sense to me?

if the water heater is electric, you won't see any energy savings over a simple electric heater you can just plug in and you don't have to do any work to get that going!

if it's NG or propane fired, you could just do the same thing by plumbing an NG or propane fired heater in its place.

you will have a slight thermal store if the power goes out due to the heat stored in the hot water of the tank, but then no fan to power it.

this is NOT the same as a radiant floor system. i don't really see the advantage of going this route unless you're just looking for a project.

if i had a small hot water heater sitting around, i would put it in my shop to heat hand washing water, use it to preheat my clothes washer or dish washer, or possibly use it to run a radiant floor system in the lean-to.

amp

 

[RonMar]

As mentoned, an auto radiator will rupture if exposed to domestic water pressure. Also as mentioned, there are better ways to heat air with electricity than via a hot water tank and radiator. There will also be quite a bit of warm up time to get any heat out of it, and it will keep putting out heat quite a while after it is shut down. Oh, and can you say LEAD solder, so it and any potential domestic water interface is a no-no...

IF you want to put a radiator system into an existing domestic hot water system to provide instant heat after a door has been opened, you will need a fan-coil unit rated for domestic water pressure like this one http://cgi.ebay.com/OUTDOOR-WOOD-FU...photoQQcmdZViewItemQQ_trksidZp1742.m153.l1262 This is an example, and may not be the right size for your needs. This type are made of copper pipe and are rated to handle domestic water pressure. They are usually available from places that sell outside wood fired boiler systems and supplies. You will also need a circulation pump such as a Taco 004 or 006 or similar cartridge pump to move the water thru it. These type liquid to air heat exchangers/radiators are NOT suitable for thermosiphon. The small water tubes go across and loop back so you can get no vertical flow thru it for the cooler water to fall out the bottom and power the thermosiphon process.

IF you don't plan to pressurize it, or ever use the system to provide drinking water, it can be done with a auto radiator If the tube passages in the radiator were vertical, it can be set up to thermosiphon and circulate heat from tank to radiator without a pump. You just need to make sure the system stays full to the top of the radiator, that the top of the radiator is above the top of the tank and that there are no excessive highs or lows in the line between tank and radiator. I cool my diesel generator via thermosiphon and it circulates just fine. But if it is just for heating air, it will waste energy just setting there keeping the water warm when not in use.

If you have a few parts on your hands and are looking for a project, go for it, but it won't be any more efficient than a direct electric to air heater.

Now if you have a reasonably free source of heat, It might make sense to use an old radiator to heat air, at least it does to me I am converting a small wood stove to an outside boiler. This will thermosiphon up to an auto radiator inside my garage to move the heat from the boiler to the garage. The system will be full of an anti-freeze mix and not be pressurized other than a small open expansion tank above the radiator. This way I get heat into my newly insulated garage without loosing any floor space to the woodstove. It will also keep all the combustables and mess outside the garage... The radiator will be mounted to a duct box that will be fed with cool air from the floor level via a squirrel cage blower under the bench.

 

[RalphVa]

Car radiators run at only about 22 psi; whereas, even a well pump puts up 40 to 50 psi. You could easily blow out some cores or even the top or bottom off the radiator, more likely the top or bottom would blow off.

Ralph

 

[alltoys]

As mentoned, an auto radiator will rupture if exposed to domestic water pressure. Also as mentioned, there are better ways to heat air with electricity than via a hot water tank and radiator. There will also be quite a bit of warm up time to get any heat out of it, and it will keep putting out heat quite a while after it is shut down. Oh, and can you say LEAD solder, so it and any potential domestic water interface is a no-no...

IF you want to put a radiator system into an existing domestic hot water system to provide instant heat after a door has been opened, you will need a fan-coil unit rated for domestic water pressure like this one OUTDOOR WOOD FURNACE BOILER HEAT EXCHANGER 12x12 - eBay (item 170260607887 end time Sep-19-08 18:20:00 PDT) This is an example, and may not be the right size for your needs. This type are made of copper pipe and are rated to handle domestic water pressure. They are usually available from places that sell outside wood fired boiler systems and supplies. You will also need a circulation pump such as a Taco 004 or 006 or similar cartridge pump to move the water thru it. These type liquid to air heat exchangers/radiators are NOT suitable for thermosiphon. The small water tubes go across and loop back so you can get no vertical flow thru it for the cooler water to fall out the bottom and power the thermosiphon process.

IF you don't plan to pressurize it, or ever use the system to provide drinking water, it can be done with a auto radiator If the tube passages in the radiator were vertical, it can be set up to thermosiphon and circulate heat from tank to radiator without a pump. You just need to make sure the system stays full to the top of the radiator, that the top of the radiator is above the top of the tank and that there are no excessive highs or lows in the line between tank and radiator. I cool my diesel generator via thermosiphon and it circulates just fine. But if it is just for heating air, it will waste energy just setting there keeping the water warm when not in use.

If you have a few parts on your hands and are looking for a project, go for it, but it won't be any more efficient than a direct electric to air heater.

Now if you have a reasonably free source of heat, It might make sense to use an old radiator to heat air, at least it does to me I am converting a small wood stove to an outside boiler. This will thermosiphon up to an auto radiator inside my garage to move the heat from the boiler to the garage. The system will be full of an anti-freeze mix and not be pressurized other than a small open expansion tank above the radiator. This way I get heat into my newly insulated garage without loosing any floor space to the woodstove. It will also keep all the combustables and mess outside the garage... The radiator will be mounted to a duct box that will be fed with cool air from the floor level via a squirrel cage blower under the bench.

That answers all my questions. I have a pump house on my acreage that needs a dependable type of heat for the winter. Winters here can range near -50F for at least a week in January and or February. It can stay -30 for a month easy. I have had 2 electric heaters and a chicken coop heater in there and it just barely keeps the pump house from freezing during the cold stuff. The system I have seen with the car radiator was from an in floor heat system the Rad provided a fast reclamation of heat after the door closed. I was thinking my extra water tank would work perfect and be low cost alternative to electric heaters.

I hope to remedy this situation with heating the pump house when I build my new home shop combined. Until then like you say it may not be worth the expense.