Steam indirect hot water

steve_173

Does one need to upsize the boiler? Any reason not to do this other than the higher up front cost? What sort of payback period is there versus a gas hot water heater?

kcopp

Ya know...

I have done this and ya it works....not sure I would do it again.  Here are my thoughts.... to really do it right the upfront cost a of a bronze 3 pc circulator are daunting.Some may say that you don't need to do this but the bottom of a steam system can be really nasty. I had one system plug up the SSU45 coil I installed it in. The other thought is the  water htr can only be as efficient as the boiler it is in ... How old is your boiler? Finding tappings in some boilers can be a challenge too. Personally I would do a tankless unit like a Rinniai or a Noritz. They have rebates available and depending on you HW needs the cost will be very competitive to a indirect.

steve_173

New boiler

I can't do tankless because there is no way to vent it from the basement. The boiler will be new and likely wet base, gas gun fired.

Steamhead

Here's one we did

which works great- Smith G-8 and 45-gallon SuperStor. A Slant/Fin Intrepid has the necessary tappings for this too, and is approved for use with a gas gun.

steve_173

Size

How did the cost compare to a 40 gal gas hot water heater? The parts and labor are higher.



What about operating costs in the summer?



How big is that house? We had a 50 gal, but several people say to go bigger. I'm 3.5 bath.



Does the boiler get sized the same regardless of the indirect demand?

steve_173

DELETE

DELETE - double post

Steamhead

Answers

Yes, it's considerably more expensive than a 40-gallon gas heater. But it can produce a LOT more hot water- first hour rating is 212 GPH, whereas on the best standard gas one it's 43 GPH or so. It also has a limited lifetime warranty, which is unheard-of on a standard gas unit.



And you do need that bronze 3-piece circ.



I don't have summer figures for this job, but the increased heat transfer surface of the SuperStor and the boiler relative to a standard gas heater should mean the burner doesn't run as much to get the job done. Oh, and since the bottom of the tank is not heat-transfer surface, if it gets muddy the heat won't be blocked as on a standard unit.



That house has 5 bedrooms IIRC, 2 baths and two future teenagers.



There is no need to increase the boiler size when running an indirect. You're tapping the pickup factor's extra capacity.

steve_173

Hardware

What about the hardware for the indirect? Do you prefer a certain brand pump? Other hardware?

kcopp

Another option....

Is to go w/ the new  Steam wet base boiler w/ the gas gun and a tankless coil. Then add a booster tank and a small bronze circulator (taco 006). That would be a lot less money up front..... for both the tank and the circulator.  You could go w/ a properly sized tank for your needs. http://www.htproducts.com/glasslinedtank.html   or http://www.vaughncorp.com/pdf/HotstowStorage.pdf

http://www.taco-hvac.com/uploads/FileLibrary/100-1.7.pdf

steve_173

Tankless?

Many seem to say not to go tankless. They don't mention the booster tank. How big a booster tank would I use? I don't see how this is that much cheaper than indirect as I still need some tank and some pump. A smaller pump and a glass-lined tank are cheaper, but that much so? Does the tankless boiler cost more? Am I missing something? 

Steve Whitbeck

steam indirect

I have done this also.

I always put a strainer in front of the pump. I also install an aquastat right at the boiler where I pull the water off of the bottom of the boiler. I set the aquastat at 180* and wire it into the seperate control wire that fires the burner in water heating mode. You don't want or need it producing steam in the summer time.

Steamhead

We've used

B&G 100 and Taco 110 bronze pumps. Armstrong is similar to B&G. The aquastat is a White-Rodgers # 1145-33 which has an 11-1/2" probe- it can reach all the way past the brass tee into the boiler section, keeping it from making steam if only the indirect is calling.

kcopp

you need to....

price it out. Looking at all the info you have reciced you can figure it out w/ you contractor. You may be surprised.