Can't decide ... Ahs coal gun or Harmon vf3000 please help!

Do I have to incorporate a dump zone? If not will the boiler go into shutdown mode?

I have had an AHS 130 for only 3 months now I burn about 60 to 70lbs a day in a well insulated 2000 sq ft cape. I have plenty of hot water and keep the house at 67 * all the time. I don't know if this helps you but I love the unit. I have not done the maintenance that they recommend every 3 or 4 months so I don't know how that will go. I wish you luck it can be a daunting decision. I didn't go with the Auger fed units out there because of the additional space they required otherwise I may have gone with a refurbed EFM. My two cents

Thankyou all for the great feedback very interesting to hear! My first day on this site and love it! Thank you again
Brent

I've had our S130 Coal Gun running for 4 straight trouble free months now, and we're averaging 48 lbs. of coal per day overall since October 14th here in Ohio. It's a great boiler! Just add coal every 2nd or 3rd day and take the ashes out roughly every 3rd or 4th day. Our home has 1,680 sq-ft upstairs, plus an 840 sq-ft heated downstairs family room in our finished walk-out basement.

Our entire upstars and the downstairs family room/basement are kept at 68 degrees round the clock, and we also keep our heated ~750 sq-ft garage at 46 degrees.

lsayre wrote:I've had our S130 Coal Gun running for 4 straight trouble free months now, and we're averaging 48 lbs. of coal per day overall since October 14th here in Ohio. It's a great boiler! Just add coal every 2nd or 3rd day and take the ashes out roughly every 3rd or 4th day. Our home has 1,680 sq-ft upstairs, plus an 840 sq-ft heated downstairs family room in our finished walk-out basement.

Our entire upstars and the downstairs family room/basement are kept at 68 degrees round the clock, and we also keep our heated ~750 sq-ft garage at 46 degrees.

Does the coal gun come with its own circulator pump? Do you have a dump zone?

NWBuilder wrote:I have had an AHS 130 for only 3 months now I burn about 60 to 70lbs a day in a well insulated 2000 sq ft cape. I have plenty of hot water and keep the house at 67 * all the time. I don't know if this helps you but I love the unit. I have not done the maintenance that they recommend every 3 or 4 months so I don't know how that will go. I wish you luck it can be a daunting decision. I didn't go with the Auger fed units out there because of the additional space they required otherwise I may have gone with a refurbed EFM. My two cents

When I talked to Ben at Ahs he said the 130 was maintance free until the end of the heating year? What do you have to do every 3 or 4 months?

Brentski wrote:Do I have to incorporate a dump zone? If not will the boiler go into shutdown mode?

If you properly size an expansion tank there is almost always no need for a dump zone. A boiler operates normally regulating it's boiler water temperature between the aquastat upper and lower set points. Since you can not immediately stop a coal fire it keeps making heat. A dump zone is typically used to dump excess heat during an overfire condition. Another approach that I favor is storing the excess heat in the boiler. This requires an extra large expansion tank to store the hot expanding water. A detailed design analysis needs to be done to properly size the tank. The design criteria is usually to allow the pressure to increase no greater that 5psi below the pressure relief valve setting.

Shawn at AHS told me the norm is an end of the season cleanout. So far I haven't noticed anything performance wise that would lead me to believe that I should shut down and clean out before the end of the season.

Yanche wrote:

Brentski wrote:Do I have to incorporate a dump zone? If not will the boiler go into shutdown mode?

If you properly size an expansion tank there is almost always no need for a dump zone. A boiler operates normally regulating it's boiler water temperature between the aquastat upper and lower set points. Since you can not immediately stop a coal fire it keeps making heat. A dump zone is typically used to dump excess heat during an overfire condition. Another approach that I favor is storing the excess heat in the boiler. This requires an extra large expansion tank to store the hot expanding water. A detailed design analysis needs to be done to properly size the tank. The design criteria is usually to allow the pressure to increase no greater that 5psi below the pressure relief valve setting.

This makes alot of sense ... Why not keep the heat into the boiler until it calls for heat on the next cycle. The next step would be like you said to figure how big of a expansion tank. Thanx from your post it seems that you are pleased from your posts!

There are many good coal boiler manufacturers. With regular cleaning and servicing all will give you economical heating and domestic hot water. The AHS and A-A boilers are unique because of the internal combustion blower. This likely improves it's efficiency over the other designs. Specifically the heat transfer efficiency of the hot gases to the water. The blower forces the hot gases to impinge with force on the boiler vessel walls. No laminar flow here. Does it make it a better overall design than the others? It may or it may not. There is no objective test that compares coal boilers. Just select the boiler that best suits you needs. Pay close attention to it's coal loading and ash removal methods. And how you might improve them. Location of your boiler might limit what you can do. Have a plan for future improvements.

FWIW I'd like to give a plug to the vf3000, I'm heating 2140SF above grade and on occasion 1350sf below. The oil furnace this retrofit went into was rated at 130k and the hot water tank was electric. My unit is in a small insulated detached shed that I sealed up best I could. As far as harman support I wouldn't base my decision solely on that, I think you can find any support you need for it right on this site. My unit is a series loop with an 80 gal indirect hot water heater and 180k heat exchanger in a furnace plenum. Do you plan on using the unit for DHW over the summer? I will admit that my unit does struggle when the temps get to single digits and I can't really program in temperature swings, but one advantage to the VF3000 is low coal consumption to keep the fire going if you make the combustion blower mods detailed on this site. Member Highlander I believe first posed how to do this and got his summer time usage down to 12-15 lbs/day.

I have an indoor efficient fireplace (double sided with sealing ceramic glass doors, lined w/ refractory brick) that I use quite often because I enjoy the indoor radiant heat and it really eases the load on the boiler. Not to mention I have been able to obtain lots of free wood from this past october snow storm. I think you should definitely do a heat loss calc, but when comparing these boilers also eval the min amount of coal they need to maintain a fire for the shoulder season and mild winters like this. It seems like lots of folks will tell you to design to the absolute worst condition, but over the life of the unit this is pretty infrequent and if you can cover yourself with a secondary source and get a unit that doesn't consume much coal in pilot mode you will save more $ over the long run as you will be able to run into the shoulder season longer and waste less in the idle times, especially if you plan on summer DHW production. I have a feeling in the future the coal vs. wood scenario will change over to wood as a cheaper source for this of us a state or 2 away from NEPA, so being diversified is nice.

You are too early in the process to narrow your decision to two boiler manufacturers. I assure you that the VF is not large enough to effortlessly do what you want. I was quite surprised about your friends comments on the LL 110 boiler.
Lets face it, in the inclined stoker market, LL and Keystoker have been at this for some time. Jim Darcy makes a fine product with his CoalJack dual stoker models. LL has plenty of the 110's and 220's in operation. AHS has hundreds, Keystoker has tens of thousands and Axeman Anderson has tens of thousands of 130's and 260's all over the country.....as does EFM( More than AA), and most still in operation!. Plenty of Van Werts also (Arnie Huntley) .

iT WOULD BE HELPFUL IF YOU GAVE SOME IDEA WHERE YOU RESIDE.........

Let's not exclude thinkers van wert 600 (for sale) or Simplexs that are out there now. A lot of boiler for not much money and if you need a little more punch..... You don't have to worship at the EFM alter if you don't want but it is a great way of firing a boiler and passes my IOQ standards. Harman is useless as a result of customer service (and now they might choose to talk to you on Facebook - gimme a break) and after 27 pages pages of posts, failing to resolve puffbacks - that would exclude coal guns and AA in my book. LL stoves, I don't have the boiler but the AnthraKIng (hot air) is fantastic. Not an great upgrade from a hyfire but a good company to deal with. Beware of - my friend overheard a person say that GM cars are great now ..... hahahahahaha. If you don't like the LL option fair enough but don't exclude them as a result of your ditzy friend failing to size his boiler correctly. Start from, this is where I live and my heat load needs are calculated to be and then move forward. Don't be surprised at the plethora of proposed choices out there. The coal community is blessed in that there are a lot of great units for sale. Different churches, lot's of different biases. You have chosen the right fuel and been smart enough to find this board, now be a little more scientific in your furnace choice. You will have to live with that decision for a l o n g time.

coalnewbie wrote: Start from, this is where I live and my heat load needs are calculated to be and then move forward...Different churches, lot's of different biases. You have chosen the right fuel and been smart enough to find this board, now be a little more scientific in your furnace choice. You will have to live with that decision for a l o n g time.

Well said.

Brentski wrote:Rob I tried to call the local Emf dealer in my area but just got the answering machine. Are these units new or rebuilds? Theres not alot of info on there web site....?

There are lots of refurbished EFM's available, and new ones as well. They aren't the only choice, but the ratchet drive on the EFM stoker makes it very easy to adjust the boiler output.

I don't know what website you were looking at, but EFM has a very detailed manual online, and a TON of information in this forum. This should get you started:

http://efmheating.com/manuals/DF520-Installation.pdf
e-f-m Heating

coalnewbie wrote:Let's not exclude thinkers van wert 600 (for sale) or Simplexs that are out there now.

Van Wert stokers are not easily adjusted like an EFM, but they have another advantage...the pot is very deep and holds a fire REALLY well. The stoker is intended to burn buck size anthracite, and is a very rugged design. If buck is available in your area a Van Wert is definitely one to consider.

Ben from AHS... Just to assist Whistlenut a little with his numbers... We have been selling the Coalgun's since 1979 and have thousands in use. I am sure that must have been a typo..lol