Car rad for shop heating?

[mikefromme]

And you can say it till you turn blue, i doubt he is digging up a late model rad designed for pusher fans.

By your reasoning, planes can fly backwards too!

"GOOD ENOUGH IS THE ENEMY OF EXELENCE" DAD.

PS: 16 licensed operating engineers have found this entire thread (you) to be as amusing as Bloombergs idea that taxing cars in times sguare will stop lung diesase.

11:30, i have a construction meeting, Wait till they hear this story..

Actually Modine (I think they know a little on this topic) has "scientifically designed a venturi fan-shroud" with the fan in the back.

http://www.modine.com/v2portal/page...markets/building_HVAC/level_5_content_021.htm

 

[bobadame]

Mount the fan so that it blows through the radiator, the cold side. The motor will thank you. Use a shroud between the fan and the radiator to get the most heat out of it.

 

[bobadame]

You could build a nifty system with 2 identical radiators, one inside the building, one outside in an insulated box with a south facing glass front. Use a March 12v DC pump between them. Connect the pump motor and fan motor to a PV panel through a temp. switch. Too much heat, open a window, go have a beer.

 

[Keep]

Id be interested to know that also. I can figure everything else out except for the pumping part or does it even need to be pumped? I'm assuming it does need to be pumped but I thought I'd ask also.

Well you could plumb it into a cars waterpump and use an electric motor with a belt and pulley. You could spin the fan and the pump with the same motor and control it with a thermostat.

 

[Randy_che]

This thread is funny. As an actual degreed and practicing engineer, I can assure you that forced draft air cooled heat exchangers are extremely common and work very well. They have some significant advantages over induced draft in certain applications. Induced draft also work well, and similarly have advantages in certain situations. Overall, it makes no difference in this case.

I would put the fans behind the radiator and push through it. It will work just fine. It will keep the motors, bearings, wiring, and blades cooler and they will last longer. This is not a critical heat exchange operation, this is a guy looking to save a few bucks and use what he has around the shop. There's always someone telling you that their way is the only right way and is the best.

Here's a link to a discussion of the pros and cons of forced vs induced draft. Hudson corporation makes industrial air cooler heat exchangers and is one of the best. They know their stuff. Since industrial air coolers are oriented horizontally, it's slightly different than a vertical car radiator, but the basics are the same for pulling vs pushing of air through the tube bundle, as explained below.


http://www.hudsonproducts.com/products/finfan/tech.html

Comparison of Induced and Forced Draft Units

Induced Draft

Advantages

Better distribution of air across the bundle.
Less possibility of hot effluent air recirculating into the intake. The hot air is discharged upward at approximately 2.5 times the intake velocity, or about 1,500 feet per minute.
Better process control and stability because the plenum covers 60% of the bundle face area, reducing the effects of sun, rain, and hall.
Increased capacity in the fan-off or fan failure condition, since the natural draft stack effect is much greater.
Disadvantages and limitations

Possibly higher horsepower requirements if the effluent air is very hot.
Effluent air temperature should be limited to 220°F to prevent damage to fan blades, bearings, or other mechanical equipment in the hot air stream. When the process inlet temperature exceeds 350°F, forced draft design should be considered because high effluent air temperatures may occur during fan-off or low air flow operation.
Fans are less accessible for maintenance, and maintenance may have to be done in the hot air generated by natural convection.
Plenums must be removed to replace bundles.


Forced Draft

Advantages

Possibly lower horsepower requirements if the effluent air is very hot. (Horsepower varies inversely with the absolute temperature.)
Better accessibility of fans and upper bearings for maintenance.
Better accessibility of bundles for replacement.
Accommodates higher process inlet temperatures.
Disadvantages

Less uniform distribution of air over the bundle.
Increased possibility of hot air recirculation, resulting from low discharge velocity from the bundles, high intake velocity to the fan ring, and no stack.
Low natural draft capability on fan failure.
Complete exposure of the finned tubes to sun, rain, and hail, which results in poor process control and stability.
In most cases the advantages of induced draft design outweigh the disadvantages.

 

[BioHazard]

What i find more amazing is that you havent questioned whether he is using 12 volt auto fans, or adapting a 110 volt set up

I haven't asked because it doesn't matter, any old fan will work.

PS: 16 licensed operating engineers have found this entire thread (you) to be as amusing as Bloombergs idea that taxing cars in times sguare will stop lung diesase.

I'm willing to bet they were actually laughing at your horrendous punctuation and spelling. Also that you're completely wrong in this case. If I had to guess given by what you've said in this thread, the pictures you've posted, and the way you type, you (and your friends) are probably just janitors who like to feel important by calling themselves engineers. Seriously, people who type like you aren't engineering material.

Stop digging yourself into this hole. You are making an absolute idiot of yourself. In this situation it absolutely does not matter in any way what so ever what direction the air is blowing. You are trying, unsuccessfully, to make this topic WAY more complicated than it needs to be.

 

[ddrewyor]

http://www.hudsonproducts.com/products/finfan/tech.html

Comparison of Induced and Forced Draft Units

Induced Draft

Advantages

Better distribution of air across the bundle.
Less possibility of hot effluent air recirculating into the intake. The hot air is discharged upward at approximately 2.5 times the intake velocity, or about 1,500 feet per minute.
Better process control and stability because the plenum covers 60% of the bundle face area, reducing the effects of sun, rain, and hall.
Increased capacity in the fan-off or fan failure condition, since the natural draft stack effect is much greater.
Disadvantages and limitations

Possibly higher horsepower requirements if the effluent air is very hot.
Effluent air temperature should be limited to 220?F to prevent damage to fan blades, bearings, or other mechanical equipment in the hot air stream. When the process inlet temperature exceeds 350?F, forced draft design should be considered because high effluent air temperatures may occur during fan-off or low air flow operation.
Fans are less accessible for maintenance, and maintenance may have to be done in the hot air generated by natural convection.
Plenums must be removed to replace bundles.


Forced Draft

Advantages

Possibly lower horsepower requirements if the effluent air is very hot. (Horsepower varies inversely with the absolute temperature.)
Better accessibility of fans and upper bearings for maintenance.
Better accessibility of bundles for replacement.
Accommodates higher process inlet temperatures.
Disadvantages

Less uniform distribution of air over the bundle.
Increased possibility of hot air recirculation, resulting from low discharge velocity from the bundles, high intake velocity to the fan ring, and no stack.
Low natural draft capability on fan failure.
Complete exposure of the finned tubes to sun, rain, and hail, which results in poor process control and stability.
In most cases the advantages of induced draft design outweigh the disadvantages.

Score one for a real engineer who uses facts and data to back up his argument.... Randy also seems to have a pragmatic approach to the situation.
________
BUY SOLO VAPORIZER

 

[BioHazard]

Score one for a real engineer who uses facts and data to back up his argument.... Randy also seems to have a pragmatic approach to the situation.

He also agrees it makes no difference in this particular circumstance. If the OP gave us some more info about boiler BTU and how much heat he needs, we could all be more specific...

 

[z28snksknr]

Score one for a real engineer who uses facts and data to back up his argument.... Randy also seems to have a pragmatic approach to the situation.

And his Pros for the forced draft (fan = pusher) all had to do with maintenance, accessibility, and such, NOT anything to do with effective heat transfer, where the induced draft system has some benefits.

As a degreed engineer myself, for this application (since maintenance and accessibility are not significant problems), it would seem that the benefits of the induced draft (fan = puller) system has benefits from a heat exchange design point of view, which agrees with what I've said here.

I would agree though that this level of detail is probably not needed for this application, but still worthwhile for educational purposes.

 

[mad57]

Ok enough of the ******* match please... get back on track .. any hoo what amount of space can a car radiator heat? how many btus? or would it be more feasable to just by 2 strips of hot water base board. I will be watching this post as i have an oil fired heater for free if i want it and would like the look of a couple of vintage radiators hanging on the wall compared to traditional strips.

 

[nehog]

...any hoo what amount of space can a car radiator heat? how many btus? ...

Somewhat an open-ended question! A radiator designed for a big V8 will have substantially more capacity than one designed for a small 4-cyl.

Many are rated between 80K and 200K BTU.

 

[mad57]

Many are rated between 80K and 200K BTU.[/QUOTE]

Wow so its possible to have a v8 say 4 core radiator, from say 1957 all polished up in copper dress as a really cool shop heater?? possibly 2 of those bad boys hanging on the wall as really cool but functional heaters.

 

[mikefromme]

Ok enough of the ******* match please... get back on track .. any hoo what amount of space can a car radiator heat? how many btus? or would it be more feasable to just by 2 strips of hot water base board. I will be watching this post as i have an oil fired heater for free if i want it and would like the look of a couple of vintage radiators hanging on the wall compared to traditional strips.

Depends on the size of the garage, amount of windows, insulation, climate etc. I heat a 600 sq foot attached garage, in Maine with one 40k btu heat exchanger.

 

[OccupantRJ]

Many are rated between 80K and 200K BTU.

Wow so its possible to have a v8 say 4 core radiator, from say 1957 all polished up in copper dress as a really cool shop heater?? possibly 2 of those bad boys hanging on the wall as really cool but functional heaters.[/QUOTE]

You could make your own polished custom embossed logo copper tanks. I did this once on a 40 Ford pickup streetrod.

 

[Rigmaster]

I know that my father in law has an old tobacco curing barn here that used a bunch of big car radiators to transfer the heat from a big boiler that was fired with old wood chips they got from a place that made wood survey stakes.

It hasn't been operating for quite a few years, but it's basically 2 rows of full size copper car radiators, maybe 6 in each row, with a big blower pushing air thru the radiators and into a wooden barn that was full of green tobacco to be warm-air cured.


I've talked to my father in law about this set up and he said it worked great. Most other tobacco barns around here use propane-fired burners to cure the tobacco.

 

[D.J.]

Caterpillar used to put fans on motor patrols (road graders) and dozers that were designed so they could be removed and reinstalled "backwards" (for lack of a better term) to push air out of radiators instead of pulling air across engines.
________
350GTV

 

[Dragster Racer]

This is really getting beat to death. Of course it will work. We have these things called heater cores in our vehicles which heat the cabin, and the same principle applies to this on a larger scale. Being a degreed engineer, I know that this could be engineered into the ground, but why? This is an experiment any way you look at it, and the experiment will tell you way more than any conjecturing that we are doing here. The heat output will vary to some extent on the fluid velocity, the air velocity pushed or pulled, the size of the radiator and design type, the temp of the fluid and more. Unless you have a real good handle on most of these pieces of info, it's pretty much a guess. Give it a try and see how it works. Then change parts of the system if they need changing.
As far as push vs pull, one of my engineering design projects had to do with building a heat exchanger system for cooling a large pump. The differences between push and pull were not statistacally significant, but the design of the shrouding sure was. The shroud completely determines what areas of the exhchanger are being effectively used. So if you decide to push or pull air, try to build a thought out and sealed shroud. The thicker the better. I think Nike used to say, "Just do it"

 

[Blue]

Wow, this thread went stupid in a hurry....

 

[caper]

A guy I used to work for had a wood fired boiler in his basement that pumped the water in a loop through a tractor trailer rad that he had ductwork built around.The ductwork was set up like any other forced air heating system using a thermostat in the living space to control the blower.He said the blower didn't come on very often since enough heat came off the rad and up through the vents without the fan running to keep the house at temperature unless it was really cold out.He was heating his whole home with this system and found it pretty easy to heat the home with just a small steady fire in the furnace.

 

[pgreen]

Holy ****! I agree this went bad fast....

Whatever you decide, push or pull, be sure to build some sort of shroud. As dragster said above.

One of the important things in a race car radiator is a rad shroud. If this isn't done correctly, a significant portion of the air will go around the radiator instead of through it. If your radiator is marginally sized, this will be an issue. If it is oversized, this won't be apparent. We don't use fans on our race cars either...but that doesn't matter...

What really hasn't been said is that with a decent shroud, you will have more air THROUGH the radiator, and more HEAT in the garage/shop. If you just set a box fan behind the radiator, you may have enough heat to keep warm, but you aren't transferring as much heat through the radiator (aka heat exchanger), and you aren't running as efficient as you could.

 

[twarren]

I have an outside wood furnace or boiler. The hot water goes to the house, through the domestic electric hot water heater, then through a heat exchanger in my forced air plenum; then the water goes to the 24 x 36 garage through a cooling radiator from a large air compressor. behind this radiator I have a 20" box fan set to low wired through a thermostat. Works fine.

My friend does the same and for his shop, commercial garage, he uses a conventinal truck radiator with a fan behind it. The truck rad will absolutly work.

Warren...............

 

[cnc-me]

Ford 9N tractors have pusher fans, that blow air out the front.

 

[caper]

So does most forestry equipment.Fans that draw in tend to plug the rads with dust,leaves,wood chips and needles.I had one forwarder one time that I chased an overheating concern on for three days till I clued in the fan was blowing the wrong way.Ordered the right fan and steamed out the rad and all was fine again.

 

[BKB]

My dad has been using a fiero rad in his 2500sq ft house for many years. Pulled out the old electronic filter thing shoved the rad in and plumed the boiler to it. I think that rad was good for 145k BTU.

 

[green.bubbly]

So... does anybody have any pictures of a shop radiator setup? With fans on either side of course.

 

[Strouty]

+1

The heat transfer dynamics of blowing air onto a radiators surface vs. pulling air though the radiator is significantly different.

Creating air turbulence (air molecules moving around in random directions) before the air has entered the radiator will limit the amount of air that can pass through the rad, which directly relates to the amount of heat transferred.

By pulling the air through the rad, you evoke a pathway for the air BEFORE it is accelerated by the fan, so you can remove heat more effectively.

This characteristic is negated if the air path is enlarged enough, which is most likely the case with the previously mentioned Modine unit with the fan behind the core.

Can't you just turn the radiator around?

 

[MScott]

This is a bit OT, but I recall reading an article a while back about an experimental system built by Fiat in Italy that utilized a small Fiat engine to completely power and heat a home. The engine was attached to a generator which supplied electricity and the cooling system was piped into the house with the radiator in the furnace plenum so that the home was heated as the engine was cooled. Apparently it worked well although with the price of gas, it might not be economically feasible today. I have always thought that a similar setup using a small diesel engine (VW?) runing on waste cooking oil would be an interesting concept.

 

[MScott]

To get back to the OP's original question, I have been investigating outdoor wood burning stoves and spoke to a person who has actually used truck radiators as heat exchangers in his garage/workshop. His shop is a 40 x 60 steel quonset building with absolutely no insulation and when he installed his furnace he wasn't able to use in-floor radiant heat since the floor had already been poured. His solution was to use two radiators from 3-5 ton trucks with square fans behind them. He says that they throws so much heat that he is able to work in his shirtsleeves during the worst of the winter. This is in eastern Ontario, so they definitely will do the job.

I really like the idea of mad57

[/quote]
Wow so its possible to have a v8 say 4 core radiator, from say 1957 all polished up in copper dress as a really cool shop heater?? possibly 2 of those bad boys hanging on the wall as really cool but functional heaters.
03-13-2010 02:09 PM [/quote]

Even better might be rads covered by grill shells from your favourite vintage car, say a Model A or a 32 Ford. Functional wall art.

 

[bb1970]

Real interesting topic for this thread. Just like everything else in life we had to have a "licensed operating engineer" get involved and **** it up. One small sentence I wish every engineer would think about before they try to show how brilliant they are. YOU HAVE TO KEEP IT SIMPLE STUPID. By the way I think the idea of a '32 grill would be so B.A.