Heat-flow IHW

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  #1  
Old 12-23-20, 08:09 PM
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Heat-flow IHW

I've looked for IHW tanks for my new system and originally i settled on these twoHTP SSC-35, 8GPM, 50btu/hr input

Boilermate CH-41Z, 5GPM 40btu/hr input

They have decent ratings that work for my household and recommended flow requirements that match the boiler I'm looking for.

Now I was suggested twice to consider Heat-flo 40g tank.

I rejected it first time after I looked at the specs.

Very high first and next hour ratings (193g/h and 157g/h at 140F and 254/218 at 115F), which is nice, but 118k btu boiler output (!!) and 14GPM flow thru the coil! The boilers I'm considering have 40-64k output and it matches my heat loss and emitters. So this IHW tank seems to be grossly mismatched for my system and for the boiler.
But since I was suggested the same tank again, it made me think maybe i'm missing something? Maybe 8GPM flow will bring down the ratings but still make the tank operate efficiently and the ratings specified were just the max without any restriction on the boiler??
 
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Old 12-24-20, 12:42 PM
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Suggest you read on the info on these tanks. You are looking at very small boilers that in my opinion will not supply enough hot water with this boiler. You will have a small chance of some hot water if the tank is put on priority but would not take a chance. The Amtrol tank has wiring that is already set up for priority operation where the other ones you will have to add control relays.

https://www.afsupply.com/heat-flo-hf-40-residential-indirect-water-heater-40-gallons-stainless-steel.html?gclid=Cj0KCQiAlZH_BRCgARIsAAZHSBkyL3xsfVtSvrue-kYamRiGyG5P1xN8s0ZBDtulI8iX86IZLEmyplcaAv-SEALw_wcB

Scroll down to specs.

Personal opinion would be to get the required boiler which is most likely a 3 section instead of 2 with another couple of gallons of water to heat to be comfortable and have hot showers.

Just my thoughts.
 
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Old 12-24-20, 02:27 PM
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go with the ssc 35 IMO... You will be fine. Taco controller to set up priority is all.

All you need is 53k boilet to meet the ratings

More boiler mass equals longer recovery time. so spott is off on that IMO.
 
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Old 12-24-20, 06:10 PM
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spott, i agree that the boiler seems very small for the tank. but not bc the boiler is small, but rather bc the tank is huge.

my house heat loss is 43k, each of two of my zones is less than 30k emitters. 68k output boiler is more than enough for me. i have currently 40g regular hot water heater with measly 70gpm first hour rating and it's actually enough for me

hence my surprise hearing from 2nd contractor about heat flo monster tank.
 
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Old 12-24-20, 06:14 PM
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lawrosa, ssc 35 is my top choice. perfect match boiler output wise and flow rate as well. i might avoid getting a taco controller and go with a circ for IHW though.
 
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Old 12-24-20, 08:47 PM
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Nah.... Just use zone valves. Less head. K.I.S.S

Dont worry yourself to death.

Priority is the key... Read

https://mechanical-hub.com/indirects-zone-valves/
 
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Old 12-24-20, 08:53 PM
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White rodgers zone valves are full port and fast closing.

I would use this for indirect

https://climate.emerson.com/document...us-1568986.pdf
 
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Old 12-24-20, 10:16 PM
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And a 007 pump with be fine.
 
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Old 12-25-20, 04:57 PM
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larosa, that's my approach too (keeping it simple). and since peerless PF boiler doesn't support zoning and IHW with zone valves and requires an external control board i warmed to the idea of recircs all around.

white rorgers valves do have a very impressive CV, but i was told that are reliable. is it not true?
 
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Old 12-26-20, 07:28 PM
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*white rorgers valves do have a very impressive CV, but i was told that are NOT reliable. is it not true?
 
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Old 12-26-20, 09:48 PM
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121 bucks


https://www.supplyhouse.com/Taco-ZVC...-with-Priority

Just do a search of zone valves to find full port fast close
 
 

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