Welcome, Guest. Please login or register.
Did you miss your activation email?

Username: Password:

Author Topic: The miracle of primary/secondary loops or wished I had done it right before  (Read 3244 times)

mlappin

  • Fabricator Extraordinaire
  • Global Moderator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 4140
  • OWF Brand: homebuilt, now HeatmasterSS
  • OWF Model: Martin Steel Works Gen 1 then, now a G200.
  • North Liberty, Indiana
    • View Profile
    • Altheatsolutions

So completely replaced my underground line in the fall of 2014, replaced the nominal 1” pex with Logstor, that helped some. Still had a very large delta T when running the snow melt and the house was calling for heat.

Got around the last few weeks and completely replumbed my basement with 1” copper and used long radius elbows where necessary. The old system was 1” pex with everything plumbed in series which had to be cutting flow down.

Have three secondary loops right now, with a fourth in place and capped off for in the future for radiant heat, baseboards, heating a whirlpool tub, etc.

Now with with everything up and running, I have no problems maintaining a consistent 20 degree delta T, using a Taco Delta pump and before it couldn’t keep up. Sometimes seen a 30-35 degree differential or more.

Now for the strange part, the old fan coil was in a existing duct that was set up for a wood furnace we used to use to heat the house. Back draft damper in it and the gas furnace so one or the other or both could run and not interfere with one another. Problem was that duct work used a old belt drive blower, every time I tried to speed it up any it got very noisy, tried changing it once but didn’t help so left it run slow. Running that slow though if it was cold enough in the mornings it may have took 4-5 hours or longer to bring the house from 67 to 72.

The one I was using was a 20x20, the one that I placed in the gas furnace ductwork (the “normal” place) is a 15x24. The old one with the lack of air flow would still pull 20 degrees or more of heat out of the water, the new one pulls a little less than 15 and runs for half as long or less. Had a LOT warmer air out of the ducts with the old one, but you could barely feel any air movement, this old house is just old enough I figure it still loses enough heat that the old set up on a very cold day was just barely adding a little more heat than the house lost.

I still need to add a on delay timer to the furnace fan circuit as it feels like a cold draft when it first starts as the secondary loop pump hasn’t had time to get hot water thru the whole loop yet and warm up the fan coil. The wife has said something about it already so I suppose that is next.

EDIT: Forgot to add I used a generous amount of immersion type mechanical thermometers in the system as well, one at the line coming in, then one after the set of T’s for each secondary loop to track just what pulls how much heat out of the water.


« Last Edit: February 10, 2016, 12:28:40 AM by mlappin »
Logged
Stihl 023
Stihl 362
Stihl 460
Sachs Dolmar 112 and 120
Homemade skid steer mounted splitter, 30" throat, 5" cylinder
Wood-Eze model 8100 firewood processor

HeatmasterSS dealer for Northern Indiana

RSI

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 3100
  • OWF Brand: HeatMaster
  • OWF Model: G200 and B250
    • View Profile
    • RSI

Why not just at a aquastat or snap switch to the pipe after the HX to turn the fan on and make the thermostat only turn on the pump. I would think that would work better than a timer.
Logged

mlappin

  • Fabricator Extraordinaire
  • Global Moderator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 4140
  • OWF Brand: homebuilt, now HeatmasterSS
  • OWF Model: Martin Steel Works Gen 1 then, now a G200.
  • North Liberty, Indiana
    • View Profile
    • Altheatsolutions

I have a stack of 24-240 volt on delay timers in the shop for the grain setup. Also have a stack of off delay timers, can never have too many spares.

I have a box of aqua stats/thermostats as well for spares, I may try one and see if I like it.

I already have the DPDT relay in place anyways.

I wired up the whole house humidifier to kick in the old slow fan when the house isn’t calling for heat as the wife complained before that when the gas furnace fan was running due to a call for the fan from the humidifier it felt drafty.

BIG house but not a lot of ducts so the ones we do have, have a higher air flow than a more modern setup.

Using Dayton on delay timer, cut load wire in half, one end goes in, the other to the load or relay. Easy peasy unlike those stupid eaton 5 wire timers.

Currently wired so on call for heat and if the strap on aqua stat on my line coming in from the boiler is over 140 then fan kicks in, under 140 gas furnace kicks in.

Normal operation of humidifier is wired so the old slow fan runs on a call for humidity, on a call for heat a signal opens the DPDT relay and cuts the old slow fan and at the same time sends a 24V signal to the Taco relay controller to start the secondary loop pump.

I’ll try the aqua stat ideal, but still leaning towards a 3 minute or so delay so the fan coil actually has time to heat up before the fan starts. Not gonna freeze to death in those 3 minutes.
« Last Edit: February 10, 2016, 12:26:26 AM by mlappin »
Logged
Stihl 023
Stihl 362
Stihl 460
Sachs Dolmar 112 and 120
Homemade skid steer mounted splitter, 30" throat, 5" cylinder
Wood-Eze model 8100 firewood processor

HeatmasterSS dealer for Northern Indiana