To answer some questions on procedure.
I have the flow meters FULL OPEN
Adjustment to the run is done via the KEY NOT the Blue
Adjustment Cap
ALL pumps are UPS 15-58 1 Main circulator 3 Zone
Circulators.
There are 3 SS-Manifolds (see pic)
2 Are 8 Run ½” pex 250 feet +/-1%
1 Is 4 Run 1/2:” pex 250 feet +/-1%
ALL connections FEED and RETURN are ¾” pex from pump to
manifold.
The zone that I have talked about previously is below the
3zone Watts distro unit.
It has approx. 10 feet of connecting pex FEED and RETURN.
The other two zones are 40 feet and 70 feet away from pump
FEED and RETURN.
The MAIN LOOP (Boiler,exp tank etc….) see pics is joined
with 1-1/4” copper
It is approx 16 feet loop length.
THIS SYSTEM HISTORY
PROJECT HOUSE/MAIN RESIDENCE
Designed to showcase all that I do.
This system was designed with country well water on
property.
Rather than take a chance corroding system, I decided to use
a closed loop.
I used and AXIOM MF200 System Feeder for my pressure/fill
requirement on makeup.
When I first started system I used a purge cart
The main system was started up (call for pump start
disabled) hose was connected to
Fill location and relief valve was left off (highest point
of main loop.) hose attached and run back to purge cart. Ran system for 10 min.
until filled and consistent flow.
NOTE: ALL Zone pumps were off.
Also water was prevented from entering or exiting zones.
MAIN LOOP flow only.
Unhooked Purge cart and reattached relief valve and fill
cap.
Started main system pump to circulate water. (MAIN LOOP
only)
Zones are still isolated and pumps disabled.
AXIOM pres./fill is ON. Add water if needed. Pressure to
12psi.
Nice smooth operation (no crackle etc…)
Ran for 10 min. No Main flow meter to give reading. Assumed fine.
Pressure built to 12 psi, water was added (indicated by
water line moving down in tank)
AXIOM turned off by itself and system continued to run with
new settings for pres.
Turned off system and moved to manifold purge.
1hp pump in 53 gallons of clean water hooked to input of
manifold on the FEED side.
On the RETURN side I attached a hose and ran it back to
cart.
Pushed 2gpm through individual run on manifold and let run
for 10 min.
Did each run on manifold individually. at same rate
Then ALL runs on flow meters read approx. 3/4gpm per run,
STRONG AND STEADY
RAN for 10 min.
There should be no air left in the manifold system.
Turned off all Runs on manifolds at Feed and Return (Key and
Meter)
Opened feed and return to MAIN LOOP.
Since I used shark bite fitting on OUT of pump and IN of
Return manifold able to fill line by hand and reconnect.
System is now reconnected waiting to add zones to main loop.
I add the basement loop first. (8 run manifold located below
main panels 200’ of ½” pex each run.)
Open ALL runs (Key and Meter)
Open ALL shutoff’s (@manifold, @pump after check valve, @
return manifold.
Reconnect ALL electronic triggering.
Trigger Basement Zone, On comes MAIN pump, On comes Zone
pump water starts to circulate (AXIOM is on and pressure topped up and water
level tank goes down)
Run 10 min.
Check flow metres and can’t tell if working
I know I have flow because AXIOM did its job, if I open
relief valve (at top of system)
Water comes out and pressure drops and AXIOM kicks on.
CONTACT WATTS.
Email back and forth with tech department in BC (I still
have emails I think, will look for them and forward to you)
I did other zones and had same issue. I now realize that
there was nothing wrong with the flow meters they were just not sensitive
enough to pickup 1/16th to 1/8th gpm flow.
I found this out after experimentation and turning on boiler
to heat water.
Had no choice but to tough it out over the winter
I was lucky that the house stayed warm due to R66 ceilings,
R32 walls and ICF foundation. Thermal blinds and Thermal drapes. 1900 sq ft.
bungalow.
80,000 Btu boiler electric 4 stage 5.5KW elements. Average
power consumption was 6 to 10KW/H 0 to -25C outside. (as per hydro datat)
However, some of this additional power was due to use of 2 -1.5KW heaters as
supplementary heat on coldest sunless days.
LAST winter the system ran as follows.
Basement zone 8runs. 1 run ON 7 OFF ¾ to 1 gpm/ 8 run ON /
flow by 8 (not readable)
Ended up using 4 outside RUNS down to 2 when it got cold.
Alternated other two zones which are upstairs and divided up
runs to outside.
In other words, a lot of manipulation to keep house at 18C
on cold days.
So you see I was hoping to have found my answer by now, but
life has a way of getting in the way. So here I am back at it before winter
starts.
I can get the same performance as last year but I need way
better.
My problem assumes the following when sizing pump.
All circulator pumps are typically sized based on
the heat load and head loss (pressure drop) for a given zone.
- Knowing the heat
load (in BTU's) for a given zone, allows to calculate the
required circulator pump's flow rate in gallons per minute (GPM).
For hot water hydronic or radiant
heating applications, the following equation can be used:
GPM =
0.002*BTU/(Temperature Drop, F),
where Temperature Drop is the difference between supply and
return temperatures in the system and GPM is the amount of flow the circulator
must produce.
Since most of the radiant heating
systems utilize a 20F temperature drop, the formula can be changed to:
1 GPM = 10,000
BTU/hr,
meaning that for every 10,000
BTU's of heat load the circulator must output a 1 gallon per minute flow.
This system calls for
80,000 BTU/hr, circulator pump should have a minimum 8 Gallons Per Minute flow
rate at a given pressure drop.
- The next step is to
calculate the head loss, or pressure drop in the system.
Head loss is associated with friction of the water against
the internal surface of the pipes/tubing in the hydronic or radiant heating
system and restricts flow rate a circulator can produce.
Although radiant heat manifold and
PEX tubing
sizing are a different topic, this systems manifold has 8 outlets with
1/2" PEX tubing installed at 250ft length per loop and the system calls
for 80,000 BTU's.
Using the formula above, we can determine the flow rate
required for our given zone: 80,000/10,000 = 8.0 GPM.
Flow rate through every selected circuit of the manifold
equals Flow Rate divided by number of Circuits:
8 GPM/8 circuits = 1 GPM per circuit (assuming that the
circuits are equally balanced).
Using a Pressre Drop Table or Pressure Drop Chart, supplied
by the PEX tubing manufacturer, a pressure drop per ft of tubing can be
calculated at a given GPM flow rate.
NOTE: Pressure drop data supplied by
manufacturers may be available both in PSI (lbs per square inch) and in foot
(ft) of head.
For conversion, I used the following equation: 1 psi = 2.3
ft of head (for fresh water), and 1 ft of head = 0.43 psi
In this example, pressure drop per 1 ft of 1/2" PEX
tubing at 1 GPM flow rate would be approximately 0.03 ft of head).
Considering that each individual PEX tubing circuit is 250
ft long, pressure drop per circuit would be 0.03 x 250 = 7.5 ft of head.
Since PEX tubing circuits are in parallel to each other,
pressure drop per circuit is always the same as the total zone pressure drop.
So, the total pressure drop is: 7.5 ft of head
We now have the complete specification for the circulator
pump available: 8 GPM flow at 7.5 ft of head pressure drop.
I understand that other components installed within a given
zone (such as the radiant heat manifold itself, fittings, check valves, mixing
valves, balancing valves, heat exchangers, PEX tubing length (different
diameters), etc.) also have to be considered when sizing a circulator pump (see
Scheme 1 below). Pressure drop information is usually available in a form of
technical specifications or submittal sheet supplied by the manufacturer. Given
real conditions, we may add extra 2 ft of head just in case, making pressure
drop 9ft of head.
NOTE: Pump head is a term used to describe the force the circulator
develops to overcome pressure drop (pipe, fittings and valves). In a Closed
System, "pump head" is NOT the height of the building. Height (on the
Scheme above) is not taken into consideration. Regardless of this the zone
manifold is below the pump, only rise is as pex comes out of top of pump to
curve around and down to manifold. As per pics
- The next and final step, is
to match the obtained data with a correct pump on a Circulator Pump Curve
Chart Which should be the Grundfos 15*58 on mid speed??????
But it is not the case.
Hope you can help, i'm not sure if the pump is functioning
properly, from startup last winter it has never pushed what i had hoped it
would.
AGAIN
Its not that it does not work, it is that it does not
provide what the specs said it would. I have another system i did and i had no
problems with that but it was hooked to a potable town water.
This system is on a pressure/fill tank which provides a
system pressure of 12 psi on input to pump.
I have same ups15-58 on another system and it gives me 4 gpm to manifold no problem (.5gpm per run)
thanks neil