Best Of
Re: Thermal Mass: 3 Kinds?
Have found references to three locations for Thermal Mass:
1) in the Thermal Shell,
2) interior to the shell, and
3) part of the heat emitters (e.g. RFH).
References suggest that properties differ with location:
1) mass in the shell may lower heat loss by increasing mass-enhanced R-value;
2) mass in the interior may dampen and delay temperature changes; and
3) mass in the heat emitters may cause lag in responding to temperature changes, resulting in over or under-heating.
Thermal Mass and R-value: Making Sense of a Confusing Issue
Anyone know of any other type of Thermal Mass with significance for hydronic heating or any other significant properties? References?
Thanks,
gf
Re: Thermal Mass: 3 Kinds?
Have found references to three kinds of Termal Mass, each with different properties depending on location:
1) in the Thermal Shell,
2) interior to the shell, and
3) part of the heat emitters (e.g. RFH).
References suggest that
1) mass in the shell may lower heat loss by increasing mass-enhanced R-value;
2) mass in the interior may dampen and delay temperature changes; and
3) mass in the heat emitters may cause lag in responding to temperature changes, resulting in over or under-heating.
Thermal Mass and R-value: Making Sense of a Confusing Issue
Anyone know of any other type of Thermal Mass with significance for hydronic heating? References?
Thanks,
gf
Re: Thermal Mass: 3 Kinds?
Have found references to three kinds of Termal Mass, each with different properties depending on location: 1) in the Thermal Shell, 2) interior to the shell, and 3) part of the heat emitters (e.g. RFH).
References suggest that 1) mass in the shell may lower heat loss by increasing mass-enhanced R-value; 2) mass in the interior may dampen and delay temperature changes; and 3) mass in the heat emitters may cause lag in responding to temperature changes, resulting in over or under-heating.
Anyone know of any other significant type of or location for Thermal Mass? References?
Thermal Mass and R-value: Making Sense of a Confusing Issue
Thanks,
gf
Frost free sillcock rated for continuous use
Another day, another thing I learn. About to pull the trigger on a 12" Woodford frost-free (based on reccos on this forum) I see in the specifications list: "Not rated for continuous use."
After a brief internet rabbit hole I understand that this has to do with the anti-siphon system: these are not rated for continuous pressure.
Any suggestions for a good quality sillcock rated for continuous use?
(As you may have guessed I'm adding a timer based irrigation system for our plants and so will keep the bib/sillcock always on in the summer.)
Re: Radiators getting hot when heating circuit off
I think we need a complete diagram of the way that is all plumbed…
In the meantime, if there are no valves I suspect you are seeing gravity flow in the radiators. How to fix the problem, though… depends on how things are actually hooked together.
Re: End of Season Report V4: Thermal Purge-O-Rama!
Wow lots a data to sort through!
On a design day, how long is the boiler run cycle? If the boiler fires before the 7 minute post purge ends, seems the short cycles are still present?
Also if you pull the boiler to room temperature every time, does it warm beyond condensing mode when it fires, for a single zone call for example?
Those are the two concerns with over-sized boilers, short run/ off cycles and the boiler runs too cold, as it covers the load before the return warms adequately.
As I recall one goal was the de-thunking of the zone valves frequently, did that get solved?
hot_rod
Re: End of Season Report V4: Thermal Purge-O-Rama!
I'm hoping to get the gas pressure issue fixed this summer and then add the setbacks back in next season, now that I'm pretty confident the all-zone purge scheme will handle the 'freeze protection' issue pretty well (even with setbacks on 2/3 of the zones). I haven't thought about it carefully, but it's probably possible to do the all-zone thermal post-purge with just some relays. It really works better than one might expect (at least in my house), due to the following:
- There's only about ~10k BTUs stored in the boiler after firing (for my 140KBTU/hr CI boiler)
- Any zones that haven't been active in a while will be filled with cool water, which can mix with and absorb the BTUs very quickly
- The overheating is minimal when the BTUs are distributed evenly throughout the house, and the inactive zones will typically have been a few BTUs below their setpoint anyway
- For the inactive zones, it will mostly just delay them calling for heat again for a bit longer
- It can very quickly cool the boiler down, virtually eliminating standby losses for oversized boilers
fentonc
Re: End of Season Report V4: Thermal Purge-O-Rama!
Nice work! I would have kept the setback though, since that would eliminate one variable.
Now we need to come up with a multi-zone control that incorporates the post-purge feature. Caleffi, Taco, Argo et al, ya listening?
For hot-water systems with just one zone, the Beckett AquaSmart control has a thermal post-purge feature you can enable. I don't see a way to wire it for a multi-zone setup though.
Re: Specifications for 2-pipe system in large house, 1914
CI was always the first choice for HW or Steam and was never accepted for gas in most locations Now the new steam installs have gone away (mostly) and HW uses copper or pex the demand for CI fittings is pretty low compared to what is used to be.
Never seen CI in HD or Lowes and even the large supply houses like FW Webb their smaller branches usually only have malleable.
