Aquasmart, ODR with steam?.

vaporvac

In talking to the Midco burner people and my local SF rep, the conversation turned to fuel savings. Both recommended some sort of outdoor reset such as a Tekmar or Aquasmart for a lower-priced option. I've search the Wall and can't find much on using these with a steam system. In addition, the Aquasmart seems to offer more options now than when some of these posts were written. Does anyone have any recent experience with these sorts of controls and the Aquasmart in particular. How exactly does ODR work with steam and can one expect much of a savings using it?



It does look like I will be able to use a modulating burner (yeah!), just not the low Nox one which was developed to meet  the CA guidelines and was super pricey, in case that has any impact on an answer. (I know, as CA goes, so goes the nation).



Completely unrelated...I've missed reading posts by Jamie Hall. Anyone know where he's been?

SWEI

modulating burner

Midco LNB http://www.midcointernational.com/products/low_nox/index.htm is under consideration.



Fully modulating steam systems are rather rare -- I don't know of an off-the shelf control that will handle this.

vaporvac

Don't know yet...

I do not know which Midco burner yet,. I hope to on Friday. Midco advised against the Low nox for my situation as it's very expensive and not necessary in Ohio. I don't know if the other modulating burners have the same design.

It was Midco that suggested an outdoor reset and mentioned the Tekmar or Aquasmart. They thought the Aquasmart would work just as well for me.Since the same people carry the SF and the Midco,  I'm hoping they'll be aware how they fit togehter. . I had just never heard of the Aquasmart or anyone using ODR of any sort with steam.

Is that because it doesn't suit the system...I would have thought it could help alot in the swing season and I think I remember reading that the coal systems used it. Is that possible?



I will read your links,MarkS, so maybe I can ask some intelligent questions! My head was spinning after reading your post. I'd be interested in your thoughts since I'm assuming your ODR is for steam. Does it make a big difference what burner is used with ODR?

What would you suggest, SWEI or should I just wait until Midco/SF get back with me.? Thanks for answering. Colleen

vaporvac

More reading!

Looks like I know what I'll be doing tonight!

I had read about the

Pajek system long ago, but the install seemed so far away that I've

forgotten what it was about. Thanks for the reminder.

The rep at

Midco did say the Aquasmart was for steam and I could have use it on my

current atmospheric, but upon reading the specs, I too was confused how

adjusting the water temp would work with steam. They have made a lot of

changes to it in the last 3-4 years so maybe I've been reading old

stuff. Maybe I'll jst call Beckett and ask! This ODR may be something to

add in the future and I may gain the same efficiencies through the

modulating burner.

How does the burner know when to modulate? I'm

assuming it's like the old (better) modulating oven burner that have a

by-pass setting. It then coasts up to the temp and only goes to full

flame when the temp drops by a certain amount.

I'll definitely report back on the suggested burners tomorrow pm. The rep's

researching the posts here to come up to speed on my system! I suspect he'll need some time for that!

Thanks to all thus far.

Colleen

Dave in QCA

modulating burner, orifice system, etc.

I am assuming that if you are considering the Midco burner, that you are thinking of going to one boiler.  In that regard I have some thoughts.



First since your system is orificed, that changes the method of calculating the necessary boiler size.  I remember that your outlets are simply union elbows.  Have you looked inside one of your supply valves?  Do you know what maximum pressure the system was supposed to operate at?  I would assume 8 oz.  And, I would assume that there is some kind of orifice device in the valves that matches the amount of steam to the size of the radiator.  It would be wise to confirm that if you have not already.  If there is a restricting device in the outlet, than that would invalidate what I am about to explain.   First, on an orificed system, the piping and pickup allowance of 34-50% is thrown out the window.  At most, you would have a 10-15% allowance for piping losses.  This is because the orifice separates the radiators from the boiler and steam mains.  Also, the output factor for the radiators of 240BTU/ sq ft can also be adjusted downward because it is calculated at 2 psi. In an orificed system you have 0 psi in the radiators.  I use 225 BTU/ sq ft and it works just fine.   So, if your system is approximately 1400 sq ft edr, you can do the following equation.   1400 sq ft x 225 BTU/ Sq ft x 1.10 Btu from boiler/BTU = 346,500 Gross output, or DOE output needed.   The TR70 would be a good match. 



Now as for modulation of the burner, it would seem that parameters need to be known first.  First, you need to fire adequately to produce steam.  How much steam?  Well, at first, one would assume that you want to maintain something in the area of 6-8 oz of pressure in the mains when there is a call for steam.  If you adjust your radiators or sometimes turn off rooms and or a whole section of the house, than the amount of steam needed to maintain 8 oz will go down.  This is one case where a modulating burner would be very helpful.  The Honeywell modulating pressurestat will not work for this, its range is too high.  But, Dave Bunnell has set up a modulation burner at very low pressure and knows the parts that are necessary to set it up.



Now, if you want to get more complicated, you might set up an outdoor reset that could set parameters such as, at 20F and below, we want to maintain 8 oz of pressure.  Between 20F and 50F we want reset from 8 oz to 3 oz.  This would slow down how fast the rads heat on the call for heat and would make for slower more even heating.   Would it increase efficiency and/or comfort?  I'm not sure.  I suspect the effect would be minimal.  For me, setting up a modulating burner for maintain a set pressure is enough and I think it would serve you well.  In fact, I would have like to have done that myself, but Weil McLain would not vary in the burner offerings, sticking to those that have already been tested.



Read and study.    Hope we all have helped and that you don't succumb to analysis paralysis.

Rod

Controls for Steam

Hi Colleen- Here's some more reading material for you.

http://www.rdcontrolsystems.com/index.php

I haven't looked at their controls for a while but I believe they can handle 2 stage / modulated steam systems.

- Rod

vaporvac

Analysis Paralysis!

That about sums it up!!!! Very funny expression.

As an update: the SF/Midco rep hadn't actually had time to read everything pertinent so I'll talk to him again on Monday...I hope.

I am looking at 2xTRV50s stage-fired.  These are set up so the same boiler is not always used as the main boiler. So whatever burner is on one should probably be on the other. The $ of the modulating burner is not much different and I think it could work out well when things are running in a vacuum. Since the water will boil at a lower temp it would need less btu to do so. That is the theory anyway.

I also think it could help simulate the super responsive, but modulated burning of the coal fire which maintained the steam in the absence of a vaporstat. (I was hoping to snag the one off my coal boiler, but there wasn't one. Then I read they didn't use them with coal, but relied on the damper to adjust things. Anyone know if this is true?)



I'm now thing I may wait to implement any sort of ODR. At least until I understand how it could benefit my system. I just remember reading that it was sometimes used on the old coal burners.



I did read with interest the boiler sizing ideas. Thank you.  With a 2gph burner I should be sized almost perfectly to my radiation. The Modulating burner will be good when I don't need all that capacity, as in the absence of a Chauffeur I have no need to heat the Chauffeur's quarter or the garage. I may also run a hot water loop for an unheated, but well insulated space when I have time, so any excess would find a use.



 I will have to look at all my rad valves sometime soon...some are original, but the one I took apart  was empty. It's also the one that doesn't always heat.

I think the new boilers, even when properly installed, will not mean the end of my posts...just giving you all a little warning here in case you're getting sick of my questions!