Tankless, Instantaneous, Water Heaters

[JMMUSTANG]

I’m thinking about installing some. I have 6 self serv bays at this location.
I‘ve been told I could use 1 and possibly 2 for 6 bays. Looking at Takagi 10 GPM or something similar.
Any thoughts of other systems? Success or failure?

 

[OurTown]

Most car washes do not use them because all most all have a restrictor valve that throttles flow until the output is the correct temp. That means your pump can starve if direct connect or even your gravity feed tank can starve. (if you do not have a backup second cold water float valve set lower) There are charts for each unit that shows flow rate at a certain rise in temp. There is one that can be run in "commercial mode" and does not restrict flow but voids the warranty. Also they need to be descaled every once in a while. I like what Randy does and directly runs one for each bay. No issues with flow restrictions. There are several ways to use these units that are not direct connect tankless and there are several long threads on here discussing the differences. Are you trying to save space by getting rid of the big storage tank or looking to save on your gas bill?

 

[Randy]

We use one on demand tankless water heater per bay with direct feed to the pump with a water regulator set at around 5-10psi. I need to start looking for replacements, mine are getting old and parts are hard to find. No water tanks, no float valves to deal with.

 

[MEP001]

I've been seriously considering adding an on-demand heater, but circulating it in a small tank, like maybe 10 gallons. I'll probably use a stainless steel water heater as a tank since it should last forever (and I can't find an insulated storage tank that small in stainless). Part of this process will include converting high-pressure wax to low-pressure, so only the water for the soap cycle will be heated. I can start with one on-demand heater and if it's not enough I can add more if necessary, but I won't have to worry about running out of water.

 

[PaulLovesJamie]

JM, as ourtown says its the flow restrictions that are the critical factor.
I use one takagi and a 120 gallon tank.
I run the takagi at higher temp to get the unit's max efficiency, then when I draw water out of the storage tank I use a mixing valve to get it down to "car wash temps". That setup also provides higher capacity and consistency.

 

[Eric H]

JM, as ourtown says its the flow restrictions that are the critical factor.
I use one takagi and a 120 gallon tank.
I run the takagi at higher temp to get the unit's max efficiency, then when I draw water out of the storage tank I use a mixing valve to get it down to "car wash temps". That setup also provides higher capacity and consistency.

IMO, this is probably the best way to go! You get the efficiency of a tankless unit and the capacity that a Carwash needs. I have this setup but with a Rinnai unit.

 

[JMMUSTANG]

So you heat the water to max heat then store it in a 120 gallon tank.
When a bay demands a hot water function the Takagi pulls the stored water back thru the TakagI then to the bay?

 

[Eric H]

When a bay demands a hot water function the Takagi pulls the stored water back thru the TakagI then to the bay?

No. The tankless unit keeps the storage tank at a constant 130 degrees using a temp probe and a circulator pump. The water then flows out of the storage tank through a tempering valve down to your desired temp. My system goes into a small 15 gallon holding tank at the pump stand because I don’t direct feed my pumps.
If you look up “HTP Phoenix” it would be the same type of setup but the Phoenix is a pre-plumbed unit. It may be worth it for you to buy the Phoenix because you will probably save on labor for the installation. My unit is separate because of space issues. I also like my setup because I can replace individual components when they wear out vs replacing the entire assembly.

 

[JMMUSTANG]

Thanks I get it now

 

[OurTown]

No. The tankless unit keeps the storage tank at a constant 130 degrees using a temp probe and a circulator pump. The water then flows out of the storage tank through a tempering valve down to your desired temp. My system goes into a small 15 gallon holding tank at the pump stand because I don’t direct feed my pumps.
If you look up “HTP Phoenix” it would be the same type of setup but the Phoenix is a pre-plumbed unit. It may be worth it for you to buy the Phoenix because you will probably save on labor for the installation. My unit is separate because of space issues. I also like my setup because I can replace individual components when they wear out vs replacing the entire assembly.

I really like the Phoenix but the price is kinda nutty now.



http://bostonheatingsupply.com/phoenixph199-80stainlesssteelngwaterheater.aspx


IIRC tdlconcepts Thomas was talking about a setup where he ran antifreeze through a closed loop tankless water heater and then it went into a heat exchanger in the separate insulated storage tank. The tankless water heater would not get the scale built up so its heat exchanger might last a lot longer. Maybe he will be along here to correct me or elaborate on it.

 

[PaulLovesJamie]

IIRC tdlconcepts Thomas was talking about a setup where he ran antifreeze through a closed loop tankless water heater and then it went into a heat exchanger in the separate insulated storage tank.

Ourtown, that is exactly what eric & I have, I used a takagi and an HTP superstor as the separate insulated storage tank. Pretty sure eric mentioned the phoenix as an all-in-one alternative.

 

[OurTown]

Ourtown, that is exactly what eric & I have, I used a takagi and an HTP superstor as the separate insulated storage tank. Pretty sure eric mentioned the phoenix as an all-in-one alternative.

Are you heating the water or is there a heat exchanger in the storage tank and you are heating the antifreeze?

 

[mjwalsh]

Anytime the discussion comes up about tankless water heating ... IMHO ... an operator should consider data from the inlet temperature of his water & the delta rise needed. In other words ... northern climates like here in ND & like Paul & Eric to some extent have a different logistic than someone in Florida or Texas or even possibly higher inlet temperatures in Randy's Seattle area.

 

[PaulLovesJamie]

Heat exchanger in the storage tank I have.
But you could do it either way, depending on what you want and what equipment you buy.

 

[JMMUSTANG]

I was thinking about using the hot water just with soap.
Someone told me he uses it for presoak, tire cleaner and wax.
What functions are you guys heating hot water for?

 

[2Biz]

I installed the Phoenix PH199-55 back in 2014. It was less than $4k shipped. Price now without shipping is $5479. Pretty hefty increase in 7 years. But it's a great water heater. Never had an issue with it or never ran out of Hot Water!

 

[MEP001]

I was thinking about using the hot water just with soap.
Someone told me he uses it for presoak, tire cleaner and wax.
What functions are you guys heating hot water for?

Nearly all the car washes around here have hot soap and wax, cold rinse. I can see hot presoak, I've even set up some car washes with hot presoak, but I don't see any point in hot tire cleaner since it's probably not going to be hot once it gets to the tire.

 

[JMMUSTANG]

Nearly all the car washes around here have hot soap and wax, cold rinse. I can see hot presoak, I've even set up some car washes with hot presoak, but I don't see any point in hot tire cleaner since it's probably not going to be hot once it gets to the tire.

I’m going with hot soap, presoak and wax.
I think the hot presoak will help bust up the lower panel grim.

 

[cooll903]

i use hot water for all mine. i use a storage tank cause up here the inlet temps very widely between summer and winter.