sixshooter

iTrader: (12)

^Aging infrastructure is possibly because you are in Detroit. Most of the subterranean infrastructure here is less than 40 yrs old because of consistent growth. Since each local municipality is responsible for their own systems it is difficult to see that as a national problem. That being said, all too often municipalities spend HUGE sums of money on planting flowers and trees, buying private property to develop into parks, renaming roads or "modernizing" street signs, rather than replacing or restoring ancient and decaying underground utilities. But replacing or relining gravity sewer mains or freshwater transmission lines doesn't get you reelected. Underground pipes aren't sexy.

Erat

iTrader: (5)

SEVERAL BLOCKS!

Water main break traps Detroit Police officers, puts neighborhood under water | News - Home

I saw a report somewhere where someone said they were having 10 a day... That's impossible to keep up on. I believe it's more than just the cold, though it's not helping.

Joe Perez

iTrader: (8)

By which you mean a bunch of dissolved alkaline metals (calsium, sodium, magnesium), some chlorine, trace amounts of a few heavy metals, some halides, a touch of bacteria... Kind of a whole soup. Here's the latest water quality report for NYC: http://www.nyc.gov/html/dep/pdf/wsstate12.pdf The complete breakdown is on pages 10-11. Did you know that NYC is one of only five cities in the entire country whose water supply is so pure that the EPA does not require it to be filtered?




Have at it, my friend!



Also, phrase for the day: "Hydronic Fan Convector." That's apparently the proper name of the thing I built out of the go-kart radiator.

Erat

iTrader: (5)

After reading through your drinking water spec sheet i had to look up ours.
Shockingly it's pretty clean.
http://www.dwsd.org/downloads_n/cust...ity_report.pdf

The units are different and i don't really care to convert, so it's hard to compare. I do know our water is actually pretty good too. You figure we have a lot of fresh water to pick from.

Like i kinda said in my post though, a lot of contamination comes from the old crappy building you happen to be in at the time.
Basically the longer the water has to go, the worse it gets as my pictures suggest.

Joe Perez

iTrader: (8)

Behold, the Beacon/Morris Twin-Flo III model K120 hydronic fan-convector:



If I've done the math properly, this should be good for around 7,000-8,000 BTU/hr given my water supply, which is about 80% of the faceplate capacity of the big, noisy, expensive PTAC unit in my wall. Equivalent to about 40 feet of the baseboard radiator I was looking at earlier. We'll know for sure once it's fired up and I can take some pre/post measurements.

Should be enough to turn the bedroom into a sauna when running at 100% DC, might even be adequate for the whole apartment with a few bucks worth of dryer hose thrown in.

All-copper construction on the water-facing side. And, conveniently, 5/8" OD nipples, exactly the same as the hose I already have.



As an aside, I finally got around to dismantling the old radiator to perform a FMA, and as I suspected, the core is nearly 100% blocked. Water poured into the upper tank trickles slowly out the lower. So there's no question, that poor little thing was seeing nearly nearly full line pressure, well in excess of its design-basis capacity.

By comparison, the new radiator is rated for a working pressure of 100 PSI, and a test pressure of 150 PSI, which is well above the typical domestic water pressure. (I haven't measured it here, but 40-70 seems to be the commonly cited range of nominal values.)

mx5autoxer

iTrader: (1)

I'd still prefer the base board radiators. They're quieter, don't stick out like a sore thumb, heat more evenly, and don't use electricity. The twin-flo III does have the coolness factor though.

Erat

iTrader: (5)

The base board system would work better in a closed loop system. But the way Joe has it, he would have to much waste.

These work well and are very reliable.

fooger03

iTrader: (2)

Hot damn, Joe. Well done.

Yeah, open loop, you want to extract every BTU out of the water flow possible; the fan makes sense. In for results.

rleete

iTrader: (21)

If I may make a suggestion: Put some sort of restrictor on the output side. Unless you have complete fill of the piping, you won't be getting efficient heat transfer to the pipes, and will be sending a lot of heat down the drain.

No idea what to use, or how much is needs to be blocked off. Just saying you need something in there unless you don't care about efficiency.

Stein

iTrader: (46)

Simple ball valve would suffice. It won't be a regulator but a restrictor but given a reasonably steady waterline pressure it should perform fine.

Joe Perez

iTrader: (8)

(and)Well, there were several factors which drive the decision here.


As to the purported cons of the Twin-Flo, the motor draws only 66 watts at high speed, and is fairly quiet. (I actually like a bit of white noise at night to compete with the diesel locomotives just outside my window.) Additionally, it is highly efficient, claiming appx. 9,000 BTU/hr from 1 GPM of 125° water on 65° air. (I estimate that this is roughly double the heat output I was getting from the go-kart radiator, given that that system seemed to max out at around 0.5 GPM)


In favor of the Twin-Flo, it is extremely compact and lightweight, which is important given how frequently I move. I can also pick it up and carry it from one room to another, just as I used to do with the go-kart radiator. And I know from experience that, with forced-air, I can extract damn near all the useful energy from the water (lowering the outflow to nearly room temperature), which allows me to keep the flowrates reasonable.


Weighing against the baseboard, obviously, are size, weight, cost, and lack of portability.

Additionally, the efficiency on those units is not high. The datasheet for the Slant/Fin "Baseline 2000" series claims about 230 BTU/hr per linear foot at 125°, presupposing 4 GPH. In other words, you need to run the water through quickly enough that the outflow temp is very near the inflow temp. This is fine and dandy in a two-loop closed system where you're recovering the water and re-using it, but not really practical in my application.

Joe Perez

iTrader: (8)

Huh?

Getting complete fill is easy. You just turn the water flow up to 11 for about 20 seconds, and you can hear the air getting blasted out of the system. It was the same deal with the go-kart radiator.

Only the inlet and outlet are 1/2". The core itself is much narrower tubing (maybe 1/4?), so it's not like huge air pockets have anywhere to hide. Also, the core itself is the lowest point in the system. The outflow water has to go about 3' uphill and then through a J-pipe in order to hit the sink, so once the system is purged, it will remain air-free even if the flow is shut off completely.

sixshooter

iTrader: (12)

Joe beat me to it. I was about to say, the outlet is higher than the unit so it will always remain full after initial purging.

Efini~FC3S

iTrader: (4)

What's the capital expenditure amount up to?

I mean, how much money are you spending to continue "sticking it to the man"?

Joe Perez

iTrader: (8)

Haha.

Well, I should have just done this correctly the first time. (It is the cheap man who spends the most.) Cost on this unit was $250 shipped, but it ought to work.

To be fair, while this started out as a "**** you" to the man, I've actually come to much prefer the performance of a hydronic system over the PTACs that the apartment came with. Yes, it's nice to have a $65 electric bill in January, but the bigger benefit of this is to have an apartment that is uniformly warm and comfortable, without large temperature swings and the noise of big electric heaters kicking on and off all the time.

Joe Perez

iTrader: (8)

Up and running:



I can already tell that this unit is making more airflow, and putting out more heat, than the original hack-job. Still needs some fine-tuning of the controls, but I have an initial dataset, based on an entirely arbitrary first-guess at water flow.

Feedwater inlet temp is 122°, outflow is 98°, flowrate is 0.41 GPM, starting air temp was 59°. Fan is at high speed for this test.

1 BTU is the amount of energy exchanged when 1 lb of water changes temperature by 1°F. 1 gallon of water = 8.345 lbs.

0.41 GPM = 24.6 GPH, which is 205 lbs/hr.

I am dropping 205 lbs/hr of water by 24°F, so that's 4,920 BTU/hr.

That's well within the range I expected based on original projections (see post 165), and about half of rated capacity, which makes sense given that I am running it at slightly less than half the rated flowrate, having simply guessed at the setting based on a back-of-hand measurement of outflow.

I have increased the flowrate slightly, still well under 1 GPM. Stack temp is about 80° right now, and the bedroom has already warmed up from 58° to 64° in about an hour, and with the door wide open at that.

I do believe we have a winner here.


Meet the heat:

mx5autoxer

iTrader: (1)

Your calculations tickle my nerd pickle.

mgeoffriau

iTrader: (7)

I use the same UPS that you do, Joe.

Joe Perez

iTrader: (8)

Well, somebody needs to tickle your pickle, and I know you're not getting it anywhere else.



It is a good UPS, which has served me well.

Its much smaller cousin is out in the living room powering the network rack.

JasonC SBB

If so inclined to build one, here's my suggested control system, using an Arduino or some such:

Regulate fan speed proportionally to water outlet temperature minus ambient temperature, something like over a 5-10* band.

Regulate water flow rate proportionally to target ambient temperature minus actual ambient temperature, over say a 2* band, but clip flow when water outlet minus ambient temp is more than say 12* or 15*F.

When room is warming up fan will max out and water flow will be regulated to 15*F outlet temp over ambient. When ambient is within 2* of target, water will regulate proportionally to ambient temperature, and fan will regulate to maintain the outlet temperature to minimize heat loss in the outlet water.