iDRY Vacuum Kilns

Sponsors:

EC-2400 - no heat load, how long for water temp to drop?

Started by Bob Lentz, March 15, 2012, 07:52:01 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

Bob Lentz

Just curious,

I was watching my OWB today (it's very,very warm out) and was wondering why the water temp was dropping with no heat load?
It's just circulating the water from the boiler into the house and back out. Nothing is pulling heat from the water.

I would think in Idle mode in these conditions, it would take quite a while for temp to drop. But not so in my case.

Thoughts?

eClassic-2400
Triangle Tube Backup (Propane)
Heating 6500 sqft house and small pool

doctorb

It takes a long time which will depend mostly, IMO, upon the length of your underground pipe run to your house and the type of insulation around your pipes.  I lose 6-7 degrees coming from the stove to the house (300 feet).  I presume that temp loss also occurs on the way back.  I found in my winter shutdown experiment this year- see thread entitled OWB winter shutdown - that the heat loss is mostly due to circulating the water.  The greater the heat loss in your system between the OWB and your basement, the greater and more rapid temp drop of the water temp in the OWB.  These are very well insulated stoves and are not much affected by ambient outside temps.  My loss was about 20 degrees a day with no fire at all and the pumps running.  I isolated the OWB water from the heat exchanger for this test.
My father once said, "This is my son who wanted to grow up and become a doctor.  So far, he's only become a doctor."

Bob Lentz

DOC - great info.
My pex run is about 25ft - not much at all.  All the pex is insulated.
I'm gonna watch it closer tomorrow.

eClassic-2400
Triangle Tube Backup (Propane)
Heating 6500 sqft house and small pool

Andy M

I got my Aquatherm up and running now for a few weeks. My thermo-pex is still above ground and I don't think it is losing more than the 1 degree loss the guy told me it would be at 100 foot run. This really does seem to be the best pex on the market from what I have researched. Costly and tough to bend, but I think I will be satisfied. I shut the blower off on the OWB the other day because the outside temps. reached mid 60's, and the boiler temp wasn't dropping it was increasing with the smoldering wood inside of it. Being new to this OWB stuff, I started dumping the heat inside the house by raising the thermostat to 80 degrees. I really need to get my other heat exchanger set up in my pole barn so I can dump the heat in there. I too still have a lot to learn about these warm day operations, but there is good advise on here and always picking up something helpful.

doctorb

If you are still tinkering with your system, make sure you add thermometers to the outflow and inflow of your boiler as well as in your basement.  You will learn quite a bit looking at the temperature gradients between these points.  No offense to your dealer, but I think you'll lose more than 1 degree in transport.  In the great scheme of things, you can't do too much about that, except use good pipe with a good install.  A small but measurable loss of heat is normal with these systems.
My father once said, "This is my son who wanted to grow up and become a doctor.  So far, he's only become a doctor."

Dean186

In reference to OWB water temperature heat loss during idle periods.  A loss of one degree per hour would be very good - IMO.  I would expect most installations to loose more than one degree an hour and maybe up to 5 degrees per hour.

As stated above: During idle periods, heat loss is from the fact the outdoor furnace is outside, heat exchanger still radiates heat into the room, and most important - the heat loss to the earth via the water line.

I also agree about the need for temperature gauges.   Here is a photo of the 4 temperature gauges, located at the heat exchanger that I use to monitor the heating system.  In the right upper corner of the photo, one can see the digital thermometer probe installed in the water line.




DeerMeadowFarm

Clean looking install Dean! Why are you bypassing your filter?

Dean186

Quote from: DeerMeadowFarm on March 21, 2012, 01:31:20 PM
Clean looking install Dean! Why are you bypassing your filter?

Thanks DeerMeadowFarm for the installation comment.  I was wondering if someone would ask about the filter. 

I felt the filter might be to restrictive when a lot of BTU s were needed.  I made a way to bypass the filter, for both filter maintenance and high demand BTUs.  I force all of the boiler water through the filter at times and during peak BTU demands I have all the valves open allowing some water to flow through the filter.  My dealer, for his installation, paralleled two filters. 

The filter keeps the water in the boiler very clean, and thus keeps my heat exchanger clean - which was the goal.  I change the filter every year.

Dean

ParadisePA

Mine was acting similarly a few weeks ago.  It turned out to be my controller (the water temp wasn't actually dropping;  it was an issue with the controller and how it read the temp).  A new controller fixed it.  I was told by my dealer that CB had some bad controllers in 2011 (mine was made in May 2011).

Thank You Sponsors!