1,000,000 btu's, 3-stage modular, oil-fired,radiant system

Alaska Joe

You need a 1,000,000 btu's of heat load, you got room for three boilers, the system is 90 percent radiant floor, and $75,000.00 to play with. Oil-fired is required, and yes, there's going to be glycol installed no matter how much you fight. What type boilers would you spec and why? Tell me your experiences....Thanks!

Unknown

I like these

http://www.slantfin.com/prod-caravan.html

You can get factory support and info for them at 1 800 873 4346.

Noel

Steve Ebels

You got questions, I got questions

All one zone? If not, what btu's are the zones? largest, smallest? What percentage antifreeze? Some particular reason you need three boilers, why not just two? What percentage of the heating season does that system actually spend at your design load?

Sounds like a fun job!

Alaska Joe

Goodmorning

No, system has a dozen zones, mainly eight 100,000 btu radiant zones, smaller office area zones are 30-50,000 baseboard zones, minus-twenty, and ten percent of the heating season. Anti-freeze is already in the system, will test in the next few days. The boss had a nice radiant system upgrade several years ago, but failed to replace the old boiler due to cost. Now we have the money I'm told....

Radiant Wizard

Without a Doubt

Viessmann

Alaska Joe

Hello Chris

I take it that you've had some good experiences with Viessman. Locally our suppliers are just now starting to show the Viessman line of products. Any particular model you like for commercial applications?

Eric

Location, location, location

Joe-

Where's your building? I'm guessing Not in anchorage with oil and not in fairbanks with only -20F. Power quality in Bush?

Type of boiler depends location. Maintenance and parts and RELIABILITY is most important. I would tend to stick with what is standard up here. Burnham makes a nice boiler and Mechanical Sales does a good job for service.

Get a good automatic gyclol makeup tank Wessels makes a nice one. Consider HX to keep glycol out of boiler. Remember you're looking at a 33% higher for alaska costs out of Means.(location, location, location).

Good luck

Ted_5

Viessmann Rondomat

is a great oil boiler. It uses two stage a Weishaupt burner
87% Eff. Can have return temps down to 120F because of the return comes in below the flame and an injection tube that takes the return water and injects it into each section equaly. Viessmann also has many different control options for your system. I think it would be worth your time to check into it!!! The rep for your state is Bob Marshal his # 775-849-0725 or www.viessmann-us.com

Good Luck,

Ted

Steve Ebels

Another German,

Boiler that might be excellent for this application would be Buderus. Their 315 series comes in outputs of 350,454,559,683 and 768k BTU's. These boilers have no minimum return temp due to their construction. Supply temp has to be held above 131*. Full 3 pass design with right or left swing door. They can be had with your choice of Beckett, Riello or PowerFlame in single stage or two stage. They run 87% plus or minus .5% in my experience. No refractory to break down in the combustion chamber.

If it was my system, I'd probably go with single stage burners for simplicities sake, use the 559,000 for my lead boiler and bring on a 454,000 for my second stage when the weather gets ugly. If you ever want to reverse the lead stage it's just a matter of changing a couple wires on the control. Buderus' 2107 control will stage the boilers and run a mixing valve with the addition of the appropriate slide in cards. It also can be programmed for setback, outdoor reset, warm weather shutdown, etc. etc. The pump logic feature will automatically maintain that 131* supply temp. saving you the trouble and expense of a shunt or bypass pump.

I don't see where using three boilers would save you a lot of money on operating costs and would definitely run you more $$$ up front and for the piping. For max system efficiency, I'd size up my baseboard zone to provide enough heat with no more than 150* water at design temp. Low water temp = high efficiency.

Viessmann would also be a good choice although higher cost. I don't feel personally that there is enough difference, if any, between the Rondomat and the 315 series to justify the higher cost. In fact I think that you have to use a boiler bypass with the Rondo. Don't get me wrong, Viessmann is a great product and I use a LOT of them. In your case, the benefits don't justify the $$$$. JMHO as always.

Happy Hydronicing in the great white north.

Walt Risler

I am in the process of purchasing 3 boilers for a large state project. I had quotes from Cleaver-Brooks and Bryant, these are duel natural gas/oil units, and around the BTU range you were looking for. The quote from either company was identical at $65,000. We decided on the Cleaver-Brooks for this project. I think I was quoted around $120,000 for 3 Viessmann boilers for a differant job, I have heard good things about Viesmann but they are so expensive. hope this helps.

Alaska Joe

Goodmorning

Obviously these post times are EST. I've downloaded the Viessmann Rondomat info, will head for the Buderus site next. Thanks for your inputs, please keep them coming in. The red salmon are running so thick on the Kenai and Russian rivers that they doubled the catch limits, I'm putting work on hold till Monday, 'Gone Fishing!' Thanks again! Joe

Steve Ebels

Walt

Just curious as to what model Cleaver Brooks and what model Viessmann you were comparing. Viessmann is always a little higher but not by that much.

Boilerpro_3

Steve, the reason for 3 boilers,IMHO

Well most of us know that in most areas, the calculated load for 90% of the heating season is only about 60% of peak (hence two boiler are better than one), what doesn't get take into account in this load calculation is internal gains. Lights, people, showers, cooking, solar gains, etc. all reduce the typical day load even further. I find in heavily populated structures, such as apartment building, offices, or in churches where much of the structure is in setback most of the time, the typical day winter load is at most 1/3 the design load plus pick up due to internal gains. I always try to use 3 boilers in these applications, or at least divide the load 1/3 to the lead boiler and 2/3 to the lag boiler.

Boilerpro