On Demand Pre-Soak Heater

[Bubbles Galore]

My dated hot water production boiler cannot keep up with my demand on busy days in the automatic. I have talked with Washworld and they recommend a 6 GPM unit for the pre soak passes at about 120 degrees. I would be uaing natural gas and would like to hear some recommendations for a high efficiency unit.

Thanks!

John

 

[Kirb]

John,
Turn your boiler up and put in a mixing valve.

 

[Sudzie]

We run both of our washes with only Rinnai heaters. 3 at one (softtouch cloth tunnel) and 2 at the other (touchless tunnel) Work Great at both washes. If you have a on board unit I would pre feed with the Rinnai. The LS 94i has a flow rate of up to 7 gpm and 140 high temp. Full disclosure we also opperate a oil & propane co.

 

[tobaccofarmer]

This is what I would use Takagi Tm-32


http://www.takagi.com/download/product_specifications/T-M32.pdf

 

[Bubbles Galore]

This is what I would use Takagi Tm-32


http://www.takagi.com/download/product_specifications/T-M32.pdf

Based on what I am seeing in the pdf, the flow rate wouldn't be sufficient at 120 degrees. Have you experienced any problems with this or is your demand lower?

 

[pitzerwm]

Have you thought about the PreSoak eating up the heater. On my unit it used a tank with a hot water type heater, then pumped it out. Worked fine.

 

[Bubbles Galore]

Have you thought about the PreSoak eating up the heater. On my unit it used a tank with a hot water type heater, then pumped it out. Worked fine.

I was only intending to feed the sta-rite pump, not run the actual solution through it. Am I missing a fundamental characteristic of these systems?

 

[bigleo48]

Bubbles,
My M5 has an electric one that keeps up...but electric not good.

A tankless might be good if you can feed the hot water from it into the existing one so that the delivery is as instant as possible.

Rinnai's...I have 8. They work well but I feel have a design flaw IMHO. The electronics were mounted at the bottom and the heat exchange above. I had an exchanger leak and ruined the electronics The Takagi's electronics are on top. The Rinnai's are also more expensive.

I really like my new NTI boiler (available thru Kleenrite). Glow plug fired, great modulation and can pump way more heat per BTU rating than the Rinnais.

 

[Bubbles Galore]

Bubbles,
My M5 has an electric one that keeps up...but electric not good.

A tankless might be good if you can feed the hot water from it into the existing one so that the delivery is as instant as possible.

Rinnai's...I have 8. They work well but I feel have a design flaw IMHO. The electronics were mounted at the bottom and the heat exchange above. I had an exchanger leak and ruined the electronics The Takagi's electronics are on top. The Rinnai's are also more expensive.

I really like my new NTI boiler (available thru Kleenrite). Glow plug fired, great modulation and can pump way more heat per BTU rating than the Rinnais.

Thanks for the feedback Big. I have a cold water feed for my auto and I was going to use that to feed the on demand heater that would feed directly into the sta-rite pump. Does that make sense?

 

[bigleo48]

Thanks for the feedback Big. I have a cold water feed for my auto and I was going to use that to feed the on demand heater that would feed directly into the sta-rite pump. Does that make sense?

Well...its just delivery time. So the tankless has to fire and generate hot water, then its gotta bleed to the tip of the arch. That might take too long... You might need to put a small electric heater ahead of it to get quick hot water while the tankless gets going.

 

[Sudzie]

You just need to put in a circ. pump and have it come on for a bit prior to use. Pm me and I can send pictures of our touchless tunel presoak arches. Chem is not a problem along with air injection. We have our circ. come on when the conveyor starts up. We have a 25 ft run to the arch and it takes 12 seconds for 135*f water to be at the head of the arch. 3628 cars washed in February this year on 387 gals of LPG. Came out to about .30 cents per car for the whole wash.

 

[bigleo48]

You would need to do some configuring for this to work as most Tankless units require .5 gallon draw before they fire. So you would need a bigger circ pump that fires when wash is activated by the entry system.

My tankless on my IBA side actually have a small tank, so my circ pump works for my pet washes.

 

[Sudzie]

You would need to do some configuring for this to work as most Tankless units require .5 gallon draw before they fire. So you would need a bigger circ pump that fires when wash is activated by the entry system.

My tankless on my IBA side actually have a small tank, so my circ pump works for my pet washes.

You are correct on the .5gpm flow for it to turn on. But with that said most taco models are close to the same price .25 to 3.0 gpm. We found that a 1.0 works fine and use the one that is stainless wet end. Make sure you have a feed check valve and a return flow check installed.

 

[tobaccofarmer]

You could plumb 2 together to achieve greater flow, All I did was plumb 1 and have it feed a 60 gallon electric water heater, that way I have a greater amount of hot water ready and available. The instant feeds the electric which just keeps it hot 120ish and I always have plenty of hot water. Never had an issue with not having enough!

 

[JIMT]

But with that said most taco models are close to the same price .25 to 3.0 gpm. We found that a 1.0 works fine and use the one that is stainless wet end. Make sure you have a feed check valve and a return flow check installed.
__________________
The Auto Spa Car Wash
York & Kittery, Maine

What are taco models with the stainless wet end? Your other post said that you use Rinnia and it costs 30 cents per car. Is that to just heat the presoak?

Thanks
JIMT

 

[Bubbles Galore]

So I think I have found the heater I am going to use. Since I am still going to feed this tankless unit with the water from my boiler storage tank, the temperature rise needed at most will be roughly 60 degrees. This should allow me to maintain my flow rate while still getting optimal temperature right at the feed out to the wash arch. It's a Takagi high efficiency unit that I can get from Dultmeier for about $1,200. Anyone see any issues why this wouldn't work?

Thanks!

John

 

[MEP001]

It may have a flow restriction device that reduces the flow through the unit until it builds to the temp you have it set for. That could be a problem since your boiler is already having issues keeping up with demand. If it falls behind, you won't have the flow you need for your presoak.

I'd try and find a solution that takes the load off the existing boiler entirely.

 

[Sudzie]

But with that said most taco models are close to the same price .25 to 3.0 gpm. We found that a 1.0 works fine and use the one that is stainless wet end. Make sure you have a feed check valve and a return flow check installed.
__________________
The Auto Spa Car Wash
York & Kittery, Maine

What are taco models with the stainless wet end? Your other post said that you use Rinnia and it costs 30 cents per car. Is that to just heat the presoak?

Thanks
JIMT

Taco 008 stainless for each pre soak arch (we have two of them) and the .30 CPC includes tunel heat. 2/ 60 ft verberay (sp) tube heaters from airlift. We did have a warm February.

 

[Bubbles Galore]

It may have a flow restriction device that reduces the flow through the unit until it builds to the temp you have it set for. That could be a problem since your boiler is already having issues keeping up with demand. If it falls behind, you won't have the flow you need for your presoak.

I'd try and find a solution that takes the load off the existing boiler entirely.

I'm trying to stay under 200k btu's to keep from having to have another boiler inspection. I may be able to call Takagi and see if they have a flow restrictor on there. Good advice, thanks!

 

[Bubbles Galore]

Okay, I have my Takagi TH-2 plumbed with the water feed lines and gas lines. I'm trying to understand if regular schedule 40 pvc is sufficient for the exhaust piping for this unit? I thought I could use regular pvc, but want to check here before I go and spend the time and effort. FYI, I did call a local company and they wanted to charge me a service call fee...