Boiler recommendation

Wayco Wayne_2

Hey guys. Long time since I visited. I am more familiar with the mod con boilers since a lot of what I do is radiant floors and with the lower water temperatures the mod cons make the most sense. However, I am looking to take out a couple boilers for a large greenhouse. They are two Fulton boilers rated at 1 million btuh each. Interestingly they are condensing boilers, but someone should have saved their money. Since the greenhouse emitters need very hot water these boilers have never condensed. I noticed that the original contractor ran the condensate line in galvanized steel. If the boilers had condensed at all, that pipe would have corroded away by now. I am looking to upgrade to a standard efficiency boiler and to divide the load between 4 boilers for redundancy. I'm looking for simplicity and easy maintenance. What brands are you familiar with and would recommend? Thanks for your input.

Robert O'Brien

Big fan of Buderus CI boilers, you would probably need G334's

lchmb

I know you wont condense but have you considered the HTP's? With the ability to cycle on demand and communicate we have saved two recent jobs a substantial amount of fuel. The most recent is heating 3 pools and a large emporium. The boiler's are cycling as demand needs and it is working to design beautifully...as it warms the boilers start to split the load, yesterday at 40 degree's the boiler's were at 53% cycle each...just a thought for ya..

njtommy

I would still say Mod con just because of stilling being able to modulate down. Instead of banging on and off.
What are the BTU requirements?

Wayco Wayne_2

2 million btuh. This is 100% redundant though so I can go don a little and still be covered. I was thinking of going with 4 Laars Mighty Therms controlled by a tekmar boiler contol. I'm looking for simplicity.

SWEI

So the actual load is only 1MM BTU/hr? What are the fuel costs like? Roughly how many hours per year do they need heat? Air quality issues from the environment?

At that size, there are quite a few options worth considering.

nicholas bonham-carter

Is outdoor reset part of the design here, for the shoulder seasons? Maybe an analysis of the past fuel consumption would be helpful in confirming the needed BTU's.
What happened to the old Fulton boilers?
With several smaller boilers, 50% redundancy may be enough.
The control system will be interesting to set up.--NBC

CMadatMe

I'd go with two Viessmann Vitocrossal CM2-311s, don't have to be prim/sec piped and can be common vented. No 3rd party control needed. Boiler already cascade ready and comes with its LON Cables for communication. They are high mass but even running 160 degree water you can still get over 90% out of them. While the min modulation rate on a single boiler is 222,000 each would run at 111,000 to get that min. Can't get more efficient then that for a simple system.

Note: You would have to add Common Vent Damper option if you decided to common vent, if not, then 8" Stainless or PPS for each and you're done..

Built you a complete spec, if you want to take a look. Combustion Air Devices, adaptors and common vent dampers options if you need them.

http://www.vitoteam.com/Pages/eng/sub/submittal.php?b1=2xCM2-311&c1=2xGW6B&v1=2xFVD-311&a1=CADA&a2=CCADI&a3=N70&

Rich_49

Have a look at these .

http://www.htproducts.com/enduroti.html

arborus14

Hydrotherm KN Series - Cast iron condensing.