Wood boilers and clothes dryer? what do you know

[hamradio]

I'm very interested in waste oil boilers. I've converted a home fuel oil burner to run on used motor oil, tranny fluid, hyd. fluid, etc. On a waste oil burner yahoo group, someone showed how they tied their drier into their hot water boiler. They put a ton of that finned baseboard heat stuff in it. Like 21 feet total, or something like that. Apparantly, it worked. My thought is, that if you were to do it, you could wire it up with a solenoid, so you wouldn't be wasting heat when you weren't drying clothes. Maybe a 110 volt solenoid that can handle the temp, that is in line with the motor on the dryer. When the dryer is on, the hot water is on to the dryer.

 

[Kneejerk Bombas]

A few years back I switched from an electric to a gas clothes dryer. A big difference I noticed was the volume of air the gas dryer moved compared to the electric. The gas dryers are said to be more efficient, but I wonder if the volume of heated or cooled air pulled out of the house is factored into the efficiency equation. The gas dryer moves about 5 times as much air.
Figuring out the optimal amount of air moved might be tricky.
If you need a bigger heat exchanger, you could just replace the back of the dryer with the exchanger, after all, all the air does enter through the back

 

[tawilson]

I should have said take one of the leads from the electric element and use to run a circ pump, as the element is 220v. I'm sure the tsat in the dryer will not be satisfied using a hw coil, so the pump should run when the dryer does, cept' during the cool down cycle. If it does happen to reach the cut off temp, the pump will stop. This is all theory, of course.
I like Mike's idea, screw a car radiator to the back of the dryer and trim it out nice.

 

[windthrown]

It should work tho...

I do not see why a HX that can heat a garage (2x2 ft) cannot be used to heat a clothes dryer. Use a larger fan and blow more air through the duct. So what if it takes longer to dry your clothes? Call it a "gentle heat dryer"
as a marketing plug and charge people 2x the price vs a standard dryer.

As for gas vs electric, a gas dryers will usually pay for the higher purchase cost vs electric in less than a year. Gas is far more efficient. It blows more air becasue it has to vent the gas fumes as well as heat. I am not sure how much more air a gas dryer blows out of the house though. Maybe an issue, but if you are burning wood in an OWB for free like we are, it does not really matter.

 

[MS-310]

Im seriously questioning wether you are going to be able to get a big enough heat exchanger inside the dryer to pull this off.



The elements in an electric dryer are probably somewhere in the neighborhood of 1200 degrees and have a large volume of air blowing over them.



Its going to be very hard to get a suficient volume of air to the correct temperature to make this work.

Maybe true, but im sure as heck going to try this. One thing is how many BTU's does it take to do this? If that little element only puts of like only 20,000 btus I could do this.

Thanks for the input on this guys.

 

[MS-310]

With all that OWB smoke in your eyes all the time, it is no wonder that you can even post messages on the internet. Must be awful! And all the smoke in the dryer that the OWB will produce. Smellyclothes...

Imagine how much better it would be if you had a woodburning stove in the basement that you could just string a clothesline around? :biggrinbounce2:

On a more serious note... for the OWB dryer, with the boiler temp at 180 you would get about 160 out of a HX connected to any device. Rule of thumb, you will get about a 20 degree drop in temp across a HX. 160 should still rock though, if all you need is 140.

cord arrow,

Do you really think he would do this for me..........:monkey:

I cant wait to see how much ever one gets pissed on the other thread about the smoke, I called CB and they gave me some really good info on OWB and Indoor stoves, got to love it.

I would wounder if people would buy a dryer for there owb??????
I wouldnt but maybe some would. THanks guys for the Help

 

[windthrown]

I wood buy one!

Hey, we removed $200 a month from our electric bill by intalling the handy dandy OWB here. We do not have NG here, and LP is really pricey. Biggest energy use here is space heating, then water heating. We nuked those two. Next is the hot tub, and then the clothes dryer. The hot tub is too complicated to heat with OWB; possible with a flat plate HX, but you need a complete bypass plumbed circuit to bypass the HX during shock treatment.

I would use an OWB fired dryer :rockn: for sure. We have a strange utility room here anyway with lots of space. We have a std pair of washers/dryer for the clothes, and my girlfriend has a separate washer for cleaning fleece (alpaca and sheep wool; she raises those animals here).

 

[MS-310]

Hey, we removed $200 a month from our electric bill by intalling the handy dandy OWB here. We do not have NG here, and LP is really pricey. Biggest energy use here is space heating, then water heating. We nuked those two. Next is the hot tub, and then the clothes dryer. The hot tub is too complicated to heat with OWB; possible with a flat plate HX, but you need a complete bypass plumbed circuit to bypass the HX during shock treatment.

I would use an OWB fired dryer :rockn: for sure. We have a strange utility room here anyway with lots of space. We have a std pair of washers/dryer for the clothes, and my girlfriend has a separate washer for cleaning fleece (alpaca and sheep wool; she raises those animals here).

The hot tub is very easy to hook up, well worth it, ask your CB dealer for there Technical Illustration Manual it shows you ever thing.

Jack

 

[RaisedByWolves]

I do not see why a HX that can heat a garage (2x2 ft) cannot be used to heat a clothes dryer. Use a larger fan and blow more air through the duct. So what if it takes longer to dry your clothes? Call it a "gentle heat dryer".

Generally its easier to heat cold air than it is to heat hot air. This plus your not pulling fresh air into the garage are working in your favor in this scenerio(heating the garage).

Once the air passes over the HX in your dryer App, it doesent get a chance to go round again. It would seem to me that you would need several layers of heat exchangers to get your air temp up to what you are hoping.

Either this or slow down the airflow to near nothing, and then the electricity of tumbling the clothes for hours is going to outweigh the benefit of this setup.


Im of the opinion that the air entering the normal dryer is hotter than you might expect.

 

[ktm rider]

I have looked into using the boiler to dry clothes also. I have found the heat exchanger that is specifically made for doing this on this site.

http://us.outdoorfurnaces.com/comersus/store/comersus_searchItem.asp

Other than that I have not been able to find any technical info on how to do this at all. I sure would like to know. with 3 kids our electric dryer runs non stop. !!! if you find out please post it... Thanks.

 

[BigSpud]

I have looked into using the boiler to dry clothes also. I have found the heat exchanger that is specifically made for doing this on this site.

http://us.outdoorfurnaces.com/comersus/store/comersus_searchItem.asp

Other than that I have not been able to find any technical info on how to do this at all. I sure would like to know. with 3 kids our electric dryer runs non stop. !!! if you find out please post it... Thanks.

That link is only partial. The full link is http://us.outdoorfurnaces.com/comersus/store/comersus_viewItem.asp?idProduct=22

I am trying to figure this out myself. I just installed a Central Boiler unit and put in a takeoff for a circulator pump for my electric dryer. I have not looked into the dryer itself, but based on my experience with a Modine heater that is installed in my basement, I would guess the air will be a little cooler from the wood boiler HX than directly from the electric heating element.

The 12x12 unit in the link would have to be built into a box that takes room air and ducts it after the HX into the intake of the dryer. That is my big question right now -- does the dryer have a nice "intake"? I don't want to add a fan to the HX box, but let the dryer draw it in.

Good point was mentioned about vibration. That would be a killer for a copper connection I think.

Next week's project is to take the dryer apart and see what it looks like. I will post back the results.

Spud

 

[lapeer20m]

I am reviving this necro thread....

How come it's 2014, and nobody has posted photos and or video's of their dryer converted to use hot water instead of electricity? Does it work so terribly that nobody has been successful? This really does not seem like rocket science.

I've reduced our electric bill to just under $50.00/month. My guess is that the washer and dryer account for more than 50% of our current (pun intended) electricity usage so i want to convert my dryer. Unfortunately, i have an unusual dryer. It's a Swedish made Asko brand. I'm going to look at how it is constructed and see if i can come up with a plan. I kind of wish i had a more standard type of maytag or whirlpool dryer so i could easily find a junk one to experiment with. The Asko is smaller than a standard american dryer and is squeezed into a tight space. The neat thing is that it only takes 34 minutes to wash a load of laundry on the quickest setting, and it takes less than that to dry with electricity. Even if i doubled the drying time with hot water i would assume that this would still save a bundle of electricity.

I have a full size truck radiator, and i also have a couple of random automotive heater cores laying around. When i finally come up with a good plan i will start my own thread complete with photos.

 

[hupte]

i plumbed in a dryer that runs off my owb. i've been using it for about 4 years now. it works great. when the water is really hot (180*F) it dries my clothes 5-10 min faster than my gas dryer. when the water is cooler (140*F) it takes about 20-25 min longer than the gas dryer to dry my clothes. but it also depends on the dryer capacity, hx and fan cfm. i'm using an old electric dryer that i removed the heating element from. fortunately the dryer had a wiring schematic inside of it. so it took me about 4 days of messing around with and almost completely rewiring the whole thing, to get it working properly. it would have taken less time but i tried to run it without an additional fan behind the 12"x12" water to air hx, to make it work. i also had to change it from a 220v dryer to a 110v. it wasnt that hard since the heating element was on one hot leg of the 220. and the rest of the dryer, the motor that turns the drum and the dials, were on the other hot leg of the 220. it sounds like it would be very difficult to make a functional dryer that ran off gas or electric in the summer, and off the owb in the winter. that seems like too much complexity in one unit. after adding up all the costs i spent about $300 on my dryer. then found out a couple months later there is a company or companies, that make and sell dryers that run off a boiler. for around 400. but that was a few years back. prices may have changed by now.

i still use electricity to turn the drum and run the fan but all the heat comes from the owb.

 

[Sawyer Rob]

I've seen dryers hooked to a wood boiler... The guys put a small heat exchanger in place of the burner...

Here's what I did with a dryer I hooked to my wood furnace,

SR

 

[zogger]

Our dryer broke a few years back. We already had an outside clothesline..so..just kept using that. Ya, some days can't hang anything out, meh, it gets done eventually.

 

[lapeer20m]

I took a look inside my dryer today. I had a difficult time understanding what path the cold air takes on it's way to the heating coil. Since there are no other vent holes air must enter through the front panel.

Ultimately the air is heated by electric coils on the back panel of the machine.

I think I can easily modify the air flow to first pass through a radiator on its way to the electric coils. There is space behind or under the dryer.

I have a few other more critical projects to finish first. But when I begin the modification I will make it's own thread with step by step photos.

 

[KenJax Tree]

Our dryer broke a few years back. We already had an outside clothesline..so..just kept using that. Ya, some days can't hang anything out, meh, it gets done eventually.

Air dried undies are very comfortable

 

[taskswap]

Wow... this is a really interesting idea. Drying clothes is a big energy suck and it's all wasted heat. I considered one time trying to recapture it, but not just trying to produce that heat more cheaply. All clothes dryers are either gas or electric and we don't have gas here so electric it is - our most expensive option...

I think if I was going to give this a shot I wouldn't be doing it with direct plumbing. But a dryer basically just has a heating element inside a duct, basically just a short box. I would imagine a small heat exchanger on eBay would be easy to find. I would think something like a 7-row transmission oil cooler would be a perfect option. You could just pull the dryer away from the wall, and make the airbox a bit larger to put the unit in there - it's on the back on mine, anyway.

In fact I'm willing to bet you wouldn't even really need to modify the dryer's controls - just work out some way to get the flow going through the heat exchanger. It's basically a simple thermostat that kicks on whenever the air temp is too low, so as long as you keep the air temp up it will automatically keep the heater element off, but the dryer will still work as normal. It'll just think it was doing a really good job. But during the summer when you weren't burning, it would just use its own heater.

I'm thinking of moving the laundry room to an area behind our master bath and the wife wants radiant floor in there. Maybe I'll add a tap for it. Radiant flooring uses a lower temp anyway so you could kill two birds with one stone.

Has anybody done this? It seems like such a perfect opportunity...

 

[taskswap]

Maybe true, but im sure as heck going to try this. One thing is how many BTU's does it take to do this? If that little element only puts of like only 20,000 btus I could do this.

My dryer (a Kenmore) is on a 240V 30A breaker but only draws 22. Figure 90%+ of that is the heating element - my motor is only 1/4hp. That's only 18000 BTUs for my unit. Yours might be larger, but either way, the math seems to prove this out.

This is such an awesome idea I want to run home and tear apart my dryer. Very interested in your choice of HX. I personally think I'll try the oil cooler - they're compact, pressure tested to high levels and they can take all kinds of abuse. And they're super cheap on eBay because people are always adding them to cars to help their towing capacity (or replacing blown units).

We do a load of laundry every day - sometimes two. No kidding, with five kids, we're lucky it's that few. I'm kicking myself for not thinking of this sooner.

 

[lapeer20m]

The sticker in my dryer claims 2,700 watts. That's less than 10k btu

In fact I'm willing to bet you wouldn't even really need to modify the dryer's controls -..

I agree. I am pretty sure most dryers have a "no heat" option. Otherwise, it would be easy enough to wire in a switch or a single breaker one could easily flip that would disconnect one of the 120 volt legs. American dryers tend to have all the controls and the motor operate on 110 volts......240 only goes to the heating coil. On a gas dryer, an even easier solution is to simply turn the gas valve off in the winter. I am assuming most would want to use the dryer all winter using only owb heat, and revert the dryer back to normal operation in the summer months.

I already recover most of the heat as i vent my dryer into my house during the cold months.

The plumbing for this modification will be simple for me as the dryer sits just above my boiler room. My plan is to incorporate the dryer into the owb circuit before it reaches the main plate heat exchanger. This way the water is the hottest, and any heat "loss" will filter into the hallway. Our laundry is in the main part of our house.