New Taco 00R. Which speed to run, and where to put it?

NTL1991

Hello,



I posted a couple months ago about my 3rd floor apartment and it's poor operation at the end of the heating loop, namely in the kitchen and living rooms. Someone pointed out that my boiler's 007 is too weak.The calculations I did gave me a piping head loss of 11.12 feet at the minimum 2.3GPM which is required to heat the apartment under design conditions. At 3GPM, that head loss goes up to 17 feet of head.



Now that I ordered the 00R, and it's on its way, which speed should I be selecting on the circulator? Low speed would take care of the minimum 2.3GPM, but High speed would get me a bit more than 3GPM.



Would there be any noticeable difference between 2.3GPM and 3GPM as far as heat output from the Haydon finned-tube baseboards? Am I better off going with the low speed or a higher one?



Should this solve my heat output problems? It seems like the apartment (I keep it at 58; it's empty right now) heats up fast to about 65, and then takes forever to get to 70, and it's only in the 40's outside now...



Also, the current 007 was factory installed on the return of the gas boiler. Should I think about moving the pump to the supply side? That would place it between the boiler outlet and the expansion tank. Do I need it pumping after the expansion tank? If so, I might just leave it on the return... I might also swap the near boiler supply and return lines to get the hottest water in the living room and kitchen, rather than the over-radiated bedrooms and bath.



Thanks,

Nick

ColoradoDave

Just try it out...

Actually, no... you should compare the pump curves for the 00R to the 007.  As you can see in the attached .pdf.....

At 12 feet of head, the 00R on Low speed will provide almost 3gpm.  As you can see by the 2nd sheet attached for the 007......   it's shutoff point is just shy of 10 feet of head...   so it's not going to do so well.

I'd start the 00R on low speed and see how it treats you.  Give it a good 3-4 hours of run time and then see if it maintains the zone for you.  You probably don't need 3-4 hours, but if it can't do it by then, bump it up to the next speed.

You might also consider instead, since you're buying another pump anyway, is moving the 007 to be a dedicated pump for that one zone by itself. 

ColoradoDave

2nd attachment...

For some reason it dropped the first attachment....

NTL1991

System Curve

Thanks. I plotted the system curve on both pump curve charts and came up with the following:



-On the current 007, just about 2GPM

-On the new 00R, Low Speed, 2.5GPM

-On the new 00R, Med. Speed, a hair short of 3GPM

-On the new 00R, Hi Speed, 3.25GPM



I'm putting in the pump today, and I will test out the different speeds to see which will work best for me. These are system circulators, by the way. This 3rd floor apartment is on one single zone, and has it's own 84MBTU gas boiler. Before I did the system curves, I was wondering if I could even put the old 007 and new 00R parallel, but that would be overkill seeing the heat loss is only 23,500 BTUH.



I'm going to be re-piping the near boiler piping after I get the pump in. That will swap the return and supply, and will send the hottest water to the under-radiated kitchen and living room, and the cooler water to the over-radiated bedrooms and bath.



Thanks,

Nick

furnacefigher15

84,000 btu

To utililize the full 84000 btu



you need 8.4 gpm ( if the btu is output.)



if input btu, then you need 6.7 or so.



How did you do your calculation. 17 feet at 3 gpm seems like a very high head for baseboard.

Paul48

delta-t?

Why not a 008 Delta-T variable speed circulator and let it do all the work?

NTL1991

High Head Loop

First off, I'm correcting the errors that the heating contractor made about 3 years ago. He removed the single steam system with it's 14 radiators, converted the steam boiler to hot water for the 1st floor, and installed separate 2nd and 3rd floor boilers. All three systems are plumbed in 3/4" PEX and use Haydon baseboards. The whole point was to stop splitting bills at the end of the month for heating and hot water, or having heat and hot water included in the rent. Everything was separated, 2 new gas meters were installed, separate washers and dryers were plumbed in, as well as separate hot water heaters. No one pays a bill for something they didn't use themselves. They aren't forced to split a bill for 75 degree heat if they want their apartment 62 degrees all winter long.



OK... So, the 3rd floor boiler is definitely oversized. It's a gasser with 100MBTU input and 84MBTU output. The boiler could heat the entire house if I wanted to... The apartment's heat loss is 23,500MBTU. Using a 20 degree differential, that comes out to a minimum of 2.35GPM. With the actual 295 feet of 3/4" PEX tubing, 29 90* elbows, and ball valves, equivalent piping length is 358 feet. At the required 2.35GPM, that comes out to 11.12 feet of head with all that piping and fittings.



Also, while I'd love to buy the latest and greatest gadgets for everything in my home, I can't justify the 008 Delta-T circulator at 3 times the cost. This is rental property, after all. In my own home, that's another story...



Thanks,

Nick

Paul48

economics

It was just a thought. To keep it in perspective......after the write-off, and over the lifespan of the circulator,you are probably talking $1.50 a month in rent money.

NTL1991

Absolutely True

Absolutely true Paul, but this apartment has been empty since October, so, while doing repairs that are necessary are totally fine, buying a circulator that costs more, but ultimately gets the job done just the same, doesn't add up right now...  Granted, it might take a bit more manual work and math getting things tweaked, but I find that's the best way to start because I end up learning so much more at the end of the day...



I should note, however, that I am not one of those absentee landlords who only shows up on the first to collect the rent. After spending nearly 50K in renovations and upgrades since 1997, I take pride in the fact that I've never had a tenant move out who wasn't leaving to buy their own home.



Thanks for the suggestion, and I will read some manuals on the Delta-T circulators, to stay informed for when I might have a case where it's use is a bit more practical than this one.



Thanks,

Nick