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Joined on September 30, 2012

Last Post on March 29, 2014

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not possible, floor is not working

@ March 29, 2014 12:59 AM in Infloor Radiant Heat issue

55 kilowatt hours for a month is roughly equivalent to the output of a 75 watt bulb.  At an average temperature of 11 degrees F, it's clear the floor is not working.  Did your guests turn up the thermostat for the rinnia?

Do you have enough propane to run the system for over a month?

What is the radio control unit that you spoke of?

zone hand-off

@ March 22, 2014 12:40 AM in Please critique this design

Zone hand-off is the opposite of what all these sync systems are trying to accomplish.  The goal is to prevent dispersed calls for heat and always fire into as much of the radiation as possible.

A hand-off strategy could only make sense if the mod/con was forced to operate at a fixed setpoint.  In this case, even though the burner can modulate, the emitters can not, creating a mismatch between the house's true demand and the systems output.

In a nutshell, it's better to fire 10k total into all the radiation all the time, as opposed to firing 10k into one zone at a time.  The latter requires higher setpoints, increases temperature swings in the zone, and reduces the connected load to the boiler which increases the cycle frequency.

zone sync

@ March 21, 2014 1:21 AM in Please critique this design

The Tekmar system syncs the zones at the beginning of the cycle. The thermostats also provide indoor feedback to an ODR module, which adjusts the setpoint to match the loads at the minimum supply temp, and automatically adjusts the differential if required.

The Honeywell system is probably very similar but I have not read up on it as much.

As far as I know, there is no zone sync method that uses a hand off strategy, though. That wouldn't make sense if the system is in control of the supply temps and is allowed to adjust them to optimally match the emitters.

It would be interesting to see someone install an indoor feedback system, they seem pretty rare.


@ March 20, 2014 12:53 AM in Pex

What is the pert stuff like to work with? What's the advantage?

delta control apparently only goes to 25

@ March 19, 2014 1:46 AM in Please critique this design

A forum member named smihaila asked Lochinvar detailed questions about some of the more advanced pump control features on the boiler you are considering.

From a post titled: Some answers from my Canadian Lochinvar rep

Q3: What fine-tune parameters are available in the "Smart Control" logic
for the customization of the "Const Delta-T" operation which seems to
be supported via "0-10V BLR PMP OUT"?

A3: The Knight Smart System controller will always try to maintain a 20F Delta T (Default) but has a range from 15 – 25 using the PC Software.

boiler pump

@ March 18, 2014 1:42 AM in Please critique this design

The boiler pump would be configured to always run with the system pump somehow?


@ March 18, 2014 12:36 AM in system advice

hePex, even with its o2 barrier is not truly oxygen tight. PAP is 100% tight. PAP also moves less than regular pex due to its stiffness and substantially less coefficient of thermal expansion. Less movement generally translates to less noise, and perhaps less wear and tear if the tubing is rubbing on something sharp.

The max temperatures aren't really important here, even with a radiator system.

too good to be true

@ March 18, 2014 12:21 AM in system advice

Either they removed those kits or I am going crazy and my memory is failing me. I can't find it anywhere on that site. I recall there being manifolds with adapters included for specific pex sizes/types, but maybe it was all a dream.

sorry to get your hopes up, fixerDIYupper :(


@ March 17, 2014 12:12 AM in system advice

You can buy Uponor manifolds that come with matching QS fittings at basically no additional cost. Why do you need 80 of them?

∆T pump

@ March 15, 2014 5:49 PM in Delta p vs delta t

You mentioned saving ∆T pumps for larger zones. In this case, are you then controlling the pump directly with 0-10volt or utilizing a pulse width modulation approach?


@ March 15, 2014 3:59 PM in Delta p vs delta t

What outputs the 2-10v? There is a thermostat that does this?


@ March 15, 2014 2:10 PM in Delta p vs delta t

Are you creating your own proportional zone valves with CCVs somehow?


@ March 15, 2014 1:38 PM in system advice

People use manifolds for rads all the time. It saves time and I don't think you'll save much cash assembling your own. I'm pretty sure you can get QS adapters for anything (definetly EK20) but the cost adds up when you need a bunch of them.

cast iron rads

@ March 11, 2014 1:00 AM in Sizing a boiler in Watertown, MA

One thing to keep in mind, if your system contains a lot of water a smaller boiler won't be as responsive to thermostat changes. For example, if you like a night setback and expect to wake up and crank the thermostat, your boiler must first bring the system up to temp and that takes longer with a smaller boiler.

mixed temps

@ March 4, 2014 12:59 AM in geothermal vs. airsource

i wonder what the best way to configure such a system is. if the btu load is dominated by low temp radiant, one would hope for great cops. perhaps two storage tanks, one for each temperature, but then the question is how to control such a setup.


@ March 1, 2014 2:33 PM in Reducing mod/com output with multiple stage gas valve

3400 btu minimum with 40 to 1 mod rate is excellent. combi boilers should make great use of this if the technology pans out.

the old delta t debate...

@ February 25, 2014 12:35 AM in The best Delta T for a mod-con?

i'm curious what impact unnecessary delta has on heat exchanger efficiency, assuming identical return temp.

a true counter flow, i would think, would be dependent on mainly return temp or modulation output as the primary variables governing boiler efficiency when the system is at equilibrium.

but a lot of these modcon heat exchangers don't look like counter flow. i would think, therefore, that such designs would suffer a more significant penalty from unnecessary high supply temp output, but i haven't seen any manufacturers' data that would suggest this to be true

i wouldnt worry about the wire right now

@ February 23, 2014 8:10 PM in Help with Steam Efficiency

there is something horribly wrong if it takes 35 minutes to get heat at the closest radiator

are you sure the pressure is not going over 2psi

question jamie

@ February 23, 2014 4:53 PM in Big problem with even heat distribution, please please help!

why do the risers continue up through the ceiling

would a vent be behind the plaster, or would the vent be outside on the roof


@ February 23, 2014 2:22 PM in Big problem with even heat distribution, please please help!

it looks like the riser is capped and ends before the ceiling --am i seeing that correctly

do you know when these problems began

can you

@ February 23, 2014 1:57 PM in Big problem with even heat distribution, please please help!

take a photo of the radiator, i think that would help people here determine the type of steam distribution employed


@ February 23, 2014 1:26 PM in geothermal vs. airsource

what type of system are you trying to heat --what temperature do you need at design conditions.

you can see from the charts that the cop drops off if one needs high system temps. i was surprised though, that the btu output doesnt drop too much. and i wonder how that compares to airsource.
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