need help asap

i am getting conflicting opinions about my coal boiler set up. first i will describe what i am trying to do. i have an axman anderson aa130 that i will be using in an outdoor application. it will be located in an insulated outdoor building (my pre-existing 28x12 shed) with a coal bin in the rear of the shed. i have a couple questions on the way to run the l;ines to the boiler. first off i dug the trench to my shed 4ft deep thinking i needed to be below frost level but have now been told that is not necessary and can cause water table issues. i was told instead to dig 18 in to 2 feet. my hole is already dug with my conduit in place so i suppose i could back fill with crushed gravel. i was told crushed gravel under the pipe will help mitigate these water issues allowing it to dissipate below the pipe rather than build up and lay around the pipe in the winter months. my second delema is whether i sould use the five wrap or foam filled pipe for my oxygen barrier per to be in? i am told the foam filled is more ressitant to water infiltration and holds heat bnetter as well as being more resistant to rocks that could shift and damage the line. my third and final question is my aa130 has a domestic hot water coil, i have beentold that there are more efficient ways to heat my water that are cheaper through the use of a plate exchanger. does any one have any experience or opinions on the plate exchangers vs. the water coil? so far the ppl i have spoken with have conflicting opinions. half tell me use two 3/4" lines in the same burriede pipe and usew the coil with a circulator pump and others tell me that is unnecassary and i can just use two one inch lines and mount a plate exchanger on top of my domestic water tank? what is the best way? i only want to do this once anmd i want to do it right i really dont want to be digging up lines and repairing this setup nor do i want to be waiting for hot water thats why im using coal min the first place. well one of the reasons any way. any help will be much appreciated, i have no backround in this stuff im learning as i go. i am trying to get into this house bewfore my son starts school but doesnt look like thats gunna happen please help asap!

Don't panic yet dj. You'll get some realistic feed back in short order & I'd bet be fine before heating season gets here. Just hold your horses for a bit.

Bury a conduit like a 5" with sweeps to come up. Then you can pull any pipe you want inside, also if the pipe ever has a problem just pull it out and replace no digging. The domestic coil would mostly depend on how far it is to the boiler to the house. Don't worry about the depth unless you are in an area with a high water table or there is a spring running by your ditch.

If you have a high water table, then put a foot or so of gravel in your trench, if your soil is sandy or gravel, it will drain well on it's own, if your soil is
clay, then I'd put down some gravel.
Water is the best conducter of heat, so you do want to keep it away from the burried hot pipes.

A plate exchanger is a much more efficient way to heat your DHW.. you only need one circulator pump, one pair of 1" Pex-Al-Pex pipes and the plate
exchanger.

This is exactly what I have had for years in my instaltion, and no complaints.

Foam or multiple layers of air barriers will both work to insulate the pexalpex. I think foam may be better, but run anything inside a continous length of
conduit, or black corrugated drain pipe.. don't have any below ground joints where water can get in and conduct heat away.

I've done this instalation twice, both ways from my boiler building, one way to the house and DHW, and the other way to my shop where I heat the floor to
keep the shop above freezing.

Greg L

Greg, why do you heat the shop floor?? Ya can't ever find it except when you have one of them thar shin-digs. Couldn't help myself my old friend

dincherjack wrote:i am getting conflicting opinions about my coal boiler set up. first i will describe what i am trying to do. i have an axman anderson aa130 that i will be using in an outdoor application. it will be located in an insulated outdoor building (my pre-existing 28x12 shed) with a coal bin in the rear of the shed. i have a couple questions on the way to run the l;ines to the boiler. first off i dug the trench to my shed 4ft deep thinking i needed to be below frost level but have now been told that is not necessary and can cause water table issues. i was told instead to dig 18 in to 2 feet. my hole is already dug with my conduit in place so i suppose i could back fill with crushed gravel. i was told crushed gravel under the pipe will help mitigate these water issues allowing it to dissipate below the pipe rather than build up and lay around the pipe in the winter months. my second delema is whether i sould use the five wrap or foam filled pipe for my oxygen barrier per to be in? i am told the foam filled is more ressitant to water infiltration and holds heat bnetter as well as being more resistant to rocks that could shift and damage the line. my third and final question is my aa130 has a domestic hot water coil, i have beentold that there are more efficient ways to heat my water that are cheaper through the use of a plate exchanger. does any one have any experience or opinions on the plate exchangers vs. the water coil? so far the ppl i have spoken with have conflicting opinions. half tell me use two 3/4" lines in the same burriede pipe and usew the coil with a circulator pump and others tell me that is unnecassary and i can just use two one inch lines and mount a plate exchanger on top of my domestic water tank? what is the best way? i only want to do this once anmd i want to do it right i really dont want to be digging up lines and repairing this setup nor do i want to be waiting for hot water thats why im using coal min the first place. well one of the reasons any way. any help will be much appreciated, i have no backround in this stuff im learning as i go. i am trying to get into this house bewfore my son starts school but doesnt look like thats gunna happen please help asap!

1. If there is no water at 4' in your area, the 4' down is ok. Don't forget this is a dry year. If ground water is high or poor soil drainage, raise the lines.

2. Solid foam is more water resistant than wrap and better quality in my opinion. I would not use wrap.

3. Running domestic hot water for a distance would require another set of lines and a re-circ pump and a fair amout of cost. I recommend a indirect water heater. The problem with flat plates is they put a heck of an intant load on the boiler and require careful sizing. A indirect with a tank creates more of a buffer. Second, if you have hard water, you will be cleaning the flat plate with acid to remove minerals a lot more than a standard dhw heater.
The indirect water heater will be a more standard and packaged approach.

By the time you spend the money on the fittings, the pipe, the circulator, the plate heat exchanger, the rest of the rigamarole, it wouldn't be that much different to get a small indirect or to use a homemade side arm for your other tank. There is the thought that you could just run two 1/2" lines out there and back with no circ pump . Just would take a while for your water to get hot. The other questions are easy. Stay high and dry, The 5 wrap isn't in the same league as the foam filled. and the gravel will certainly help.

My $.02.......Add an indirect water heater in the house. The foam filled piping available from folks like Central Boiler is the way to go.
Don't overlook the OWB guys, they have done this for years and most are very good at what they do. The 4' down is always a good idea, but the soil condition is paramount. Good drainage is important, AND water proofing the holes in your foundation will be essential if you have a high water table. I didn't read the distance from the AA to the current hook=up, but try to stay with 1" ID piping.
PS: A tank-less coil will work fine as long as there direct connection from the boiler, but your application suggests an indirect would be better. Understand, an indirect 40 gallon will spoil $1000.00. With any solid fuel appliance, you need to make provisions for a slower ramp-up to temp than an instantaneous result as in oil, propane or natural gas. Slow and steady wins the btu race with coal every time.

My run is around 2' down but I have water at 4' and learned the hard way the first time. No problems with losing too much heat or worry of freezing either.

Indirect is the way to go in my opinion as well. It's the best investment I've ever made, maybe even better than the boiler...just kidding Scottscoaled. My wife almost cries when the boiler goes offline in the Spring, no more endless hot water:roll:

As for heating water time I can take a shower, walk from one end of the house to the other bathroom where the indirect 50 is and it shuts off within a minute or two thereafter.

You utilize the lines that provide your heat so no extra pipe to bury.

I use a separate pump via close-fitting tees to pull from the main loop. You don't have to and could just as easily use a valve to accomplish the same thing.

I used Uponor on my 2nd pipe install, much better stuff than my first go round which succumbed to water inhalation. I could have planted onion sets in March three years ago where the pipe was buried 4' down.

I won't speak to the piping of your system but I will say something about your trench. If you have a 4 foot trench and a high water table depending on the level of the trench you could be creating a curtain drain that actually carries water to your basement. If I were you I would bring the level up to 24" from the 4 foot level starting at least 10 to 12 feet out. Keep the foundation penetration as small as possible. Patch it from both sides with hydrolic cement and then water seal it with several coats of Thoroughseal. The last thing you want is to introduce water up against the foundation. Good luck!

http://www.centralboiler.com/Tech/C070.pdf

Go to central boiler website they have most of the answers to your questions. There will be one major difference they dont pessurize there boilers.

Some High Quality Advice from those in the know..! Just to throw in my two cents,let's recap some of the high notes:
1.) Know your average water table and soil type. The drought has definitely brought water tables down.
2.)If you haven't cut a trench all the way into the foundation yet,try to have your lines rise as you meet the foundation to enter. This can avoid the "French Drain" idea of bringing groundwater flow directly toward your foundation.
3.) I'd use 1" line in a foam filled water resistant casing,like the type Central Boiler sells. Expensive,you bet. But I like your idea of attempting to do this right the first time for the long haul. Getting that stuff to push through a larger PVC Conduit can be a chore,but may provide dividends and protection in the long run.
4.) Indirect hot water heating would seem to allow you the best use of a much simpler 2 line supply and return circuit with only one foundation breach.
5.) Lastly,an old foundation man fortunately taught me that any time you breach anything below grade through the foundation wall,you should always angle it up so that your inside piping comes through the wall higher than it is outside the wall. This gives much better resistance against ground water pushing in to the basement or crawl space. Seeling the hole is much easier,also...

Just a condensing of the great thoughts above,and I'm sure more will follow. What's so good about this Board is the fact that if someone had a question about how to build a heart/lung machine in a pinch,we've got enough well-rounded Coalers here that would come up with a solid game plan for it. Good Luck,and please follow up here with your results. Send us a few Snaps of the action in progress if you can. Like Freddy has said in the past "We Love Pictures"