High Efficiency Condensing boilers

mr bull

I agree with Andrew & scott!
One thing I would add. Don't use a Munckin, I've been out in the mountains of Colorado doing service this weekend on 2 different Munckins, both neeed new parts, both homes where cold and with out hot water. There are so many people pushing this boiler, I could see how some one may try to sell you one. They are high tech, and when working produce cheep heat, but your savings on gas will be short lived if some one has to work on it. Parts for the darn things are unreal. Hope things work out. Bull.

gmcc

High Efficiency Condensing boilers

I need a personal/professional opinion about the high efficiency boilers out there right now. I am replacing a 400kbtu AJAX dinosaur in a small commercial building (mainly because the winter months KILL me) and am considering Munchkin, Trinity, Viessmann, and the like. Probably a dual unit with an additional zone for the domestic tank. Any comments or suggestions? I have definitely heard the argument of "use whatever can be supported" but the contractors around here (Denver) aren't really adamant about anything in particular. Most are so busy, they don't even have the time to quote...

Thanks

Scott Gregg

I think you're on the right track

But start your project by having someone run a new heat loss on the structure. (Maybe you only need 200MBH!) Oversizing is still common.

Then do what you can to tighten up the building with insulation.

INSULATION IS FUEL YOU ONLY BUY ONCE AND YOU BUY IT AT TODAY'S PRICE!

I think a lot about the modern modcon boilers are still misunderstood, however the modulation aspect of them is the best reason to use them. Outdoor reset capability on some are the other best reason.

A Trinity combi with outdoor reset and an indirect is awful hard to beat. If your DHW load is light like in most comercial buildings, you don't even really need the indirect.

ALH_4

I agree

I agree with Scott. Start from scratch on the heat load and reduce the load in any way possible. One nice thing about the modulating condensing boilers is that there is less of a penalty for slight oversizing. If you install two boilers with 4:1 turndown ratios you now have 8:1 with a good staging control.

The Viessmann Vitodens has all of the controls built in for a single boiler, very high quality of construction, and excellent literature(something which cannot be taken for granted). If you install multiple boilers they have a cascade control available to stage them.

-Andrew

mr bull

> I agree with Scott. Start from scratch on the

> heat load and reduce the load in any way

> possible. One nice thing about the modulating

> condensing boilers is that there is less of a

> penalty for slight oversizing. If you install

> two boilers with 4:1 turndown ratios you now have

> 8:1 with a good staging control.

>

> The Viessmann

> Vitodens has all of the controls built in for a

> single boiler, very high quality of construction,

> and excellent literature(something which cannot

> be taken for granted). If you install multiple

> boilers they have a cascade control available to

> stage them.

>

> -Andrew

KAG

Munchkin

I have installed 20 Munchkin boilers in the last five years. The only one I had problems with was the first. Spent several hours yeiling at manufacture about how much a piece of junk their unit was. Then he finally got me to open the instructions. Opps, wrong size piping, wrong circ. on both the main and DHW. It was a mess, so I repiped it to spec and the rep come over and showed me how to set them up, even after I insulted his company. No matter which unit you choose if the installer DOES NOT follow the instructions it will break down leaving you in the cold! Since then I read, research and recheck my designs before I install anything. Oh, the first was in my own home, no problems with the other 19 and they all are on a 2 year check up schedule for cleanings and adjustments.
Have not installed any of the others yet but once trained I will, they are all quality units. But I have gone on service calls for some of them (no heat), most where installed incorrectly.