Best Of
Re: Help Sizing A Multi-Zone Mini Split System - Minimum Capacity?
"Is it worth considering Mitsubishi Hyper Heat (-13F) vs "Standard" (-5F)? The design temp that I've seen so far has been around 6F."
The big difference between the hyper heat and standard units isn't the operating temperature, it's how much capacity they keep at low temperatures. The unit I linked to earlier is hyper heat, it's rated 34K BTU/hr at 47F and 32K BTU/hr at 5F — so it keeps almost all of its capacity.
This is a similarly-sized standard unit: https://ashp.neep.org/#!/product/214502/7/25000/95/7500/0///0
It's rated 40K at 47F and 20K at 5F.
When it comes to heat pumps, the nameplate capacity is meaningless. You're never going to need more heat at 47F than at 5F. What you care about is low temperature. That 40K unit is really a 20K unit.
My recommendation would be to only look at units that could satisfy your entire heating load at a temperature between your design temperature and your average annual minimum (-1F). When you're doing a new install there's no reason not to give yourself the ability to go all-electric in the future.
Re: What to replace Vertex with for DHW and small radiant system?
I have used the Butler Solar Wand for a few micro radiant systems. Like a single bathroom.
You drop this double walled heat exchanger tube into any HW tank to pull some heat out.
hot_rod
Re: Accidentaly hit PEX with nail. Above subfloor radiant heat
Just a coupling that fits that type of tube is fine. No harm in heat shrinking it also. That is mostly for repairs in concrete pours.
Maybe make a map of the exact location, for peace of mind.
What brand of tube is it? Do they offer a crimp coupling, or just compression style?
On my Warmboard installs I would get a roll of butcher paper, lay it across the room to make a map of the exact tube location. pics or drone shots work well also.
hot_rod
Re: A question about design.
I guess at the end of the day…. it is a loop from the top of the low loss header to the bottom of the low loss header with a check valve preventing the return water from being pumped back into the zone before returning to the low loss header first…… i.e. one direction flow only.
Re: Which New Analyzer?
I just traded in my former E-Instruments 1500 that was manufactured by Seitron on a new Seitron Novo…. absolutely the best analyzer i have ever owned! Truly amazing, and I have it with built in printer (so did my 1500) and have never had an issue with the printer, works great. One of the many features is I can quickly build a model of boilers with all the combustion paerameteres, then next time I am on that type of boiler I just have to scroll down and select it, saving me time of looking ut up or trying to find the I&O manual. Yes all analyzers should have annual calibration for YOUR liability. All Seitron's have 4 year O2 sensors that are field replaceable. Seitron's service and training is second to none!! Check out my old one and my new one featured in the picture on their webpage Homepage - Seitron Americas (they are not actually mine, but new ones that look like the models I owned)
Re: Which Wall Hung Boiler?
The answer is, the brand that has local support and experience. Lochinvar, NTI, IBC, US Boiler are all reputable brands. Most brands have basic, and higher option choices.
All brands need proper installation, and occasional service, find that guy, or girl :)
hot_rod
Re: Replacing cast iron radiator with smaller one
A smaller radiator will offer you less heat. Is the kitchen too hot? …then reduce the size of the radiator.
If your kitchen is just the right temperature when the heating system is operating, then installing a smaller radiator with less heating output, will result in your kitchen will be colder.
Re: Buderus Hardware Help
If the system is set up and adjusted properly, the boiler should only run to heat domestic water when there’s a call from the indirect through the 2107 Logamatic control on top of the boiler.
The Logamatic control operates from a heating curve which means it doesn’t call the boiler on for SPACE heating from a thermostat demand, but instead, it uses an outdoor sensor and water temperature sensor to regulate the boiler’s water temperature. This is known as outdoor reset (ODR). It also has a feature known as warm weather shut down (WWSD). This turns off SPACE heating at around 68* outside. The control probably has a radiant heating card installed which operates a mixing valve for a lower heating curve for the radiant floor since the boiler must operate at a warmer temperature to prevent flue gas condensation.
I suspect that something (maybe a bad outdoor sensor) is keeping the boiler on all the time at a high temperature resulting in excessive fuel consumption.
Unfortunately, the Logamatic control is no longer available from Buderus unless there’s one on a shelf somewhere. There are other aftermarket controls that can be incorporated by a competent tech should the Logamatic be faulty.
The boiler is the best cast iron made and was the most efficient system around when it was installed. I believe the AFUE rating was 84%. If properly maintained, it could easily last 40+ years. The indirect, depending upon water conditions, 25-30 years on average.
I would recommend that you get someone like @Alan (California Radiant) Forbes to evaluate the system and see what needs to be done to correct any issues. Again, it could be something as simple as an outdoor sensor gone bad.
If the time comes, or has come, for a system replacement, a 95%+ mod/con boiler with fire tube heater exchanger + a new indirect would be the best way to go.
Ironman
Re: Replacing cast iron radiator with smaller one
@amaiale , take a pic from the end of the radiator so we can see what type and capacity are the sections it uses. Also how tall is it?
