Joined on November 26, 2011
Last Post on August 21, 2014
@ July 8, 2014 10:27 PM in Complete new system on small houseUsing what water temperature? More really is better when it comes to radiation.
@ July 8, 2014 4:37 PM in Getting into mod/con business> I'm speaking of the actual AFUE, which is not easily determined for a system.
> The actual AFUE is the only way of comparing the efficiency of one system to another system
AFUE is a computed value, and as many have mentioned here, not a particularly useful one. The real-world annual energy savings is quite simple to compute, but it does require a couple of months of winter fuel usage. Calculate the number of BTUs consumed and divide those by the number of heating degree days and you get something resembling the truth. In my world the truth is a savings of 40% or better using the math I just described. We tell customers to expect "at least 30%" and have yet to miss our mark. When replacing older, oversized, improperly controlled systems we frequently see savings as high as 70%.
@ July 8, 2014 1:22 PM in Radiant coolinghttp://www.uponorpro.com/~/media/Extranet/Files/manuals/Nonoptimized/RCDM_Manual_RC03_0513_52020red.aspx?sc_lang=en&version=051720130958 and you'll learn a lot.
@ July 7, 2014 10:39 AM in Getting into mod/con businessbecause it's different for each region and even for individual utilities. Out here NG currently costs under 70 cents per therm including fees and taxes. With our short heating season and assuming a 15 year life on the mod/con, it's a tough sell for smaller houses -- but a no-brainer for commercial projects. OTOH for customers on LPG, even a 60k design day load usually justifies one.
@ July 7, 2014 10:33 AM in Radiant coolingtake dewpoint into account. With proper design and control strategies, you can remove most of the sensible heat using radiant, leaving you freedom to optimize the MUA and latent loads.
In the southwest, we can often skip dehumidification. One afternoon last month we hit 95ºF with a dewpoint of 14ºF. I've seen spreads over 20ºF bigger in Phoenix.
@ July 6, 2014 11:34 AM in True RMSI just have to put in a plug for their 380942 mini clamp meter. I love my Fluke for higher power stuff, but the small jaw and high resolution of the Extech makes it perfect for a lot of troubleshooting tasks.
@ July 5, 2014 2:09 AM in Cleaning radiant tubingusually beginning with a street pressure flush (or crank up the Pressuretrol if they're on a well.) Once you see clean water coming out of the drain(s) then move to the next step.
@ July 4, 2014 4:55 PM in Cleaning radiant tubinghttp://www.rhomarwater.com/media/W-91001.pdf
@ July 4, 2014 3:18 PM in Low Profile Rescom 2100 Aluminum Baseboard Radiatorsbut they make you work to find the output capacity. Here's a cleaned up version of the info p.7 of the installation instructions:
PANEL HEAT OUTPUT PER LINEAL FOOT (BTU)
Test results have been adjusted to reflect a 15% radiant efficiency factor.
Data derived from factory tests February 1996. Complete test data available on request.
@ July 4, 2014 11:41 AM in Getting into mod/con businessyou are about to embark on a relationship with a manufacturer that will last a decade or more. Even if you decide to change horses in six months, you will still own the boilers you installed before you changed your mind. You are smart to be asking about this before you jump into something.
Like several others here, I have had great experiences with both Triangle Tube and Viessmann. Quality products, quality training, and they will be there for you when/if the going gets tough. Rinnai sells a good product and has comprehensive training, but the price makes them a tough sell, at least in our market. Lochinvar has very flexible onboard controls but has become somewhat of a commodity around here.
Modern modulating/condensing boilers only perform as advertised when they are properly applied, sized, installed, and commissioned. They do not tolerate fools. In a sane world, these products would only be sold to qualified installers. The unfortunate reality of our distribution system here in the US will quickly give any manufacturer who tries that the kiss of death. The better manufacturers provide incentives to their trained installers (sometimes in the form of extended warranties) to try and give them an edge over the trunk slammers who buy their products out of distribution.
@ July 3, 2014 7:27 PM in TT Smart 80 & Prestige Solo 110 Summer Gas UsageYou need to remove top jacket access panel (the rear half of the top cover) or find a moderately long dental mirror in order to see it.
@ July 3, 2014 1:19 PM in Bouncing Gas PressureAnyone know of software that supports this?
@ July 3, 2014 1:12 PM in RMSWhen you measure any waveform that deviates from sinusoidal. That would mean any time an inverter, a VFD, or a switchmode power supply is involved.
@ July 2, 2014 11:56 AM in Slab Sandwichbut I'd use a minimum of 2" insulation underneath - may even be a code requirement, but perhaps not in your climate zone.
The biggest thing is to make sure the tubing is tied to the top of the rebar, with the rebar on chairs -- keeping it in the upper half of the pour.
@ July 1, 2014 10:53 PM in Dans Reading ListAn update aired tonight http://www.pbs.org/opb/historydetectives/investigation/civil-war-sabotage/
The whole show is interesting. The final 15 minutes helped me to frame American political corruption in perspective.
@ July 1, 2014 7:49 PM in New gas boiler sizingYOUR local supply house is not in question here.
Referring a homeowner to THEIR local supply house is a complete crapshoot. Qualified hydronics installers have unfortunately become somewhat rare in America. The RPA is actively working to fix that, and a small handful of manufacturers are leading the way.
@ July 1, 2014 5:38 PM in New gas boiler sizing"your local supply house" may not have a clue about proper training and installation practices of their customers. A few do, but the majority in my experience do not. A "local boiler guy" won't cut it either.
RPA members generally have a clue -- I'd start there. The ones they have actually trained know their stuff for sure.
The rep firms are better, especially for certain brands. Viessmann and Triangle Tube come to mind as having well-rounded installer training programs. Lochinvar makes a great product, but I have no direct experience with their training programs.
@ July 1, 2014 9:43 AM in TT Smart 80 & Prestige Solo 110 Summer Gas Usageare significant, as you have just witnessed firsthand. Now that it's picking up an earlier signal, you might try increasing the differential a bit.
@ June 30, 2014 6:36 PM in Converting Oil to GasSomehow thought you had a steam system -- apologies. For hot water heating, a new boiler will indeed be much more efficient.
A properly sized, installed, and commissioned modulating condensing boiler will save more fuel than the AFUE numbers would indicate. If you convert your historical oil usage into Therms, you should save at least 30% in fuel BTUs with a new boiler.
@ June 30, 2014 5:51 PM in Converting Oil to Gas} She explained that I won't get the improved efficiency of a gas boiler vs. an oil boiler
Quite the opposite, with a properly sized and installed conversion burner.
Not sure if Charlie travels that far, but perhaps Tim knows a tech nearby who can handle the work.
@ June 30, 2014 10:45 AM in TT Smart 80 & Prestige Solo 110 Summer Gas Usageare inexorably intertwined here, and not really the point.
Let's assume for your particular location, weather, and fuel that condensation begins at one very specific temperature -- say 130ºF. The efficiency difference between return temps of 129ºF (we'll call that condensing mode) and 131ºF (we'll call that non-condensing mode) would be almost immeasurable. The curve is smooth and has a low slope.
@ June 29, 2014 6:33 PM in ECM circulatorsHas a knob on the side -- just turn it to the speed you want (we dial in the ∆T we want) and leave it there.