Economizer control for Hot Water Boiler

[Rudy]

Does anybody have any experience with adding an energy saving device to their Hot Water Boiler/Heater? I stumbled across the IntelliCon-HW+ 3250 (http://www.supplyhouse.com/Intellid...Water-Heating-System-Fuel-Economizer).....and it looks like it would indeed save money.

I have a RayPak boiler which feeds a 80 gallon Storage Tank. On dead car wash days....the boiler fires to makeup whatever standby loss occurs. This is where the device would especially work well....I think. (Overnight quiet times also....)

If I understand this device correctly, it monitors the return line temperature. On dead days, it'd see the temperature rise quickly....and therefore it "throttles back" the calls for the boiler to fire. On busy car wash days, it'd see the return line getting cold, and staying colder, longer....and it'd adjust the firing rate according.

Anyone have any experience with this?

 

[Rudy]

I've had the Economizer running for a month or so now.

It's averaging 16-18% of savings. (There's a digital display which shows the savings)

I now have a better understanding of how it works.

There are 3 "modes" for the boiler.....Heat, Standby, and Economizer.

Heat is just that......The Boiler is firing. Standby means that the standby tank has been heated, and that the aquastat is NOT calling for more heat. In Standby, the tank is hot, and the circulator is NOT running. In Economizer, the aquastat is calling for heat. The circulator starts....and the device is inserted into the firing circuit. Once inserted into the firing circuit, it monitors the rate at which the water temperature is changing. If it senses that No hot water is being used (very little change in water temperature), it does not fire the boiler....but allows the system to "coast". It will do this down to a minimum water temperature, which is adjustable. I have my aquastat set to provide 120F water....and I have the Economizer set for a minimum temperature of 90F. In this Econ/coasting mode....the lowest hot water temperature a customer would see would be 90F (and, for instance, that would only be the first customer of the day after the system had been coasting all night).

As hot water is being removed from the tank (ie the first customer of the day), the Economizer would sense that hot water is being used....and it will then appropriately switch to "Heat" mode to fire the boiler and provide more hot water.

On busy days, this device is smart. It realizes that hot water is being used (not coasting)....and therefore makes the burner firing decision appropriately.

The money savings comes from "skipping" having the burner "fire" when not highly needed.

From a customer standpoint, I doubt anyone would even notice....especially in the winter. If you were the first car to wash at 6am, would you notice that the wand was at the lower end of 90-120F for the first several minutes of washing? I doubt it. And that assumes that the customer comes in JUST BEFORE the system was getting ready to fire.

From an owners standpoint.....It makes me feel good to be working in the equipment room (on a rainy day), no customers in sight, I hear the circulator "start up", and NOT hear the boiler fire. I'm saving money in this situation.

 

[GoBuckeyes]

Rudy, thanks for posting. I may look into this. The link you provided doesn't work but I was able to decipher that the unit is made by Itellidyne. I'm assuming it's the Intellicon HW+ model?

 

[Rudy]

That's correct. Model 3250.

 

[GoBuckeyes]

Rudy, I did notice it says for units up to '300k btu'. I'm assuming your Raypack is larger than that. Any idea why they put a 'limit' on it?
Thanks.

 

[Rudy]

I vaguely remember calling their tech support line to ask....but can't remember their explanation. They were VERY helpful.

Yes my RayPak INPUT is over 300K, but the OUTPUT is under 300k.

I'm not sure that matters. (It might have something to do with the algorithm???)

Call them.....

 

[washnvac]

I use an IDX mx8 multiplexer with an ice cube relay to shut off my heater and air to the flo-jets/bays when no bays are in use. I use the timed hot from the individual bay timer to the mx8. So when one bay goes on, heater triggers, and air solenoid opens to bays and flo-jets.

This solves 2 issues. No heater running when bays are not used. And no air to anything when no bays on. This prevents that middle of the night hose burst that runs the flo-jet and empties a drum of soap. Since most customers start with pre-soak and or tire cleaner, heater has time to ramp up, even from cold start. There are no 80 gallon tanks at any of my locations, just the 15-25 gallon stainless tank mounted on the s/s skid. This heats up in no time. All lines and tanks insulated.

This can all be done for about $110, and it is very simple.

 

[Rudy]

Update...

The device is presently showing 24.5% "savings" on the readout. It's been in service about 3 months.

 

[slash007]

How easy is it to install one of these?

 

[Waxman]

I use an Intermatic mechanical timer on my production water boiler. Off at 6pm on at 6am. Storage tank holds plenty of hot for the overnight and that's half a day every day where the boiler is off.

For my floor heat I shut the doors on my SS bays nightly in the cold wx months. Works really well and saves alot!

 

[Rudy]

Easy to install.

Mount the box. Two wires get connected for the power....and you get the power from the boiler. You have to find the wire that goes from the aquastat to the "firing" terminal on your boiler control board. You cut this wire, and insert two wires from the Economizer into the circuit. The hardest part is finding the correct wire.

Took me about an hour.

 

[wash4me]

Update...

The device is presently showing 24.5% "savings" on the readout. It's been in service about 3 months.

Sound interesting. It would be nice if you could post gallons per month used off of your water bill and cubic feet off of the gas bill for the last 2 months and then do the same for whatever 2 months you can find in the last couple years that are about the same gallons of usage per month. This would give us a pretty good idea of what percent you were saving on gas. We need the gallons and cubic feet because costs of utilities fluctuate. Standby losses would be reduced but the cost to heat a gallon of water would be unchanged.

 

[MDrost1]

This looks great. Won't affect the warm weep system in anyway? Just making sure.

 

[Rudy]

The unit prints out a statistic called "A Save". This is the 24.5% number I quoted.

You'd have to call the Mfr. to be sure, but I think it's an indication of how many "firings" that have been saved.....that otherwise would have been completed.

As I've said earlier, when working in the equipment room on a quiet day, I can hear the circulating pump start (the aquastat is calling for heat). The boiler doesn't fire however. The device is "holding off" the firing of the boiler depending on the temperature change of the water temperature. This is one way this unit saves you money.

I think another way it saves.....is by delaying the "firing" when demand starts to increase.

When that first customer comes in (while the system is being "economized"), the device watches the rate of temperature change of the water. If the change is small, it senses this, and continues to hold off the firing. As demand picks up, it senses this and finally decides, "It's time to fire!"..

This system shouldn't affect your warm water weep, because, you still do indeed have warm water. During low demand times....it's not "quite as hot" as during high demand times. Don't forget, the aquastat is located towards the bottom of the storage tank, and the water above this level is hotter.

There are too many variables for me,to sit down and actually calculate this to the nth degree.

It really doesn't matter to me if the payback is a year vs a year and a half. I can tell it's saving me money, and that's what's important.

FWIW, I'd love to be able to carve some $$$$$ off my floor heat gas bill.....but since I have a modulating RayPak, it's my understanding (which may or may not be correct) that this device will not work for floor heat.

 

[WikiWash]

FWIW, I'd love to be able to carve some $$$$$ off my floor heat gas bill.....but since I have a modulating RayPak, it's my understanding (which may or may not be correct) that this device will not work for floor heat.

Rudy, please let me know if you find out for sure if it can or can not work for floor heat. I have a ray pak boiler too, that would be great if it can!

 

[2Biz]

This looks great. Won't affect the warm weep system in anyway? Just making sure.

I know this has been mentioned here before, but I can't figure out why anybody would want to weep warm water? I made it through more than one -15° night last winter weeping cold water.

wiki, I don't think one of these would help you with your modulating Floor Heat Boiler. If you have it set to maintain floor heat just above freezing (monitoring return temps) then you can't get any more efficient than that without the floors freezing.

 

[MDrost1]

Well, the way I understand it is it is not about he freezing as much as it is related to the rinse. We do warm water rinse because of the rinsing and cleaning properties. The weep system is connected to out rinse system somehow. That's all I know. I will look into a cold water weep though. Intriguing.

 

[2Biz]

I would think it would be as simple as taking the warm water supply hose off the weep solenoid and connecting it to a cold supply...When I bought our wash, the weep was plumbed using softened water. I can weep close to a thousand gallons a day below 15°. So I changed that to weep unsoftened water that comes right off the street. Saved a ton of salt and wear and tear on our softener....Its amazing how washes are plumbed differently and what the reasoning was at the time...

 

[cantbreak80]

Its amazing how washes are plumbed differently and what the reasoning was at the time...

"We've ALWAYS done it that way."
"The boss said to do it like that."
"This is the first time I've ever installed one of these."
"Installation manual? What installation manual?"

 

[Kevin James]

Well, the way I understand it is it is not about he freezing as much as it is related to the rinse. We do warm water rinse because of the rinsing and cleaning properties. The weep system is connected to out rinse system somehow. That's all I know. I will look into a cold water weep though. Intriguing.

Rinsing and weeping with warm water is a total waste of money. It’s not going help the lines from freezing and its not going help with cleaning. I’d get that on cold water ASAP.