Joined on November 26, 2011
Last Post on December 12, 2013
@ November 15, 2013 5:36 PM in Multi-unit house Electric Radiant Floor or Forced Air/Gas?a heat pump produces 2-3 kW of heat for every kW of electricity that it consumes. The exact number depends on the particular heat pump (more expensive models generally have higher efficiency) and the outdoor air temperature at the time.
@ November 15, 2013 5:31 PM in What unit to use with panel rads and sidearmget the system design right. http://www.caleffi.us/en_US/caleffi/Details/Magazines/pdf/idronics_10_us.pdf will help.
@ November 14, 2013 11:11 PM in Multi-unit house Electric Radiant Floor or Forced Air/Gas?and the owner of this rental property places some value on ROI, I would probably recommend a multi-head ductless mini-split like the Mitsubishi CITY MULTI, the Daikin VRV, or the Fujitsu Halcyon.
@ November 14, 2013 11:02 PM in Which Pipe Sealant?Does anyone make 3/8" wide Teflon tape? I'd love to have it for the small stuff.
@ November 14, 2013 7:16 PM in Multi-unit house Electric Radiant Floor or Forced Air/Gas?I'd seriously consider these http://www.rinnai.us/direct-vent-wall-furnace before I installed ductwork.
@ November 14, 2013 1:48 PM in Multi-unit house Electric Radiant Floor or Forced Air/Gas?to include appliance efficiency in those numbers. That DOE spreadsheet is really handy.
@ November 14, 2013 12:24 PM in Oil to Gas ConversionThe ~37k output of the Cadet is more than a commodity 35-40k tank heater can produce, but not a lot more. Price difference between a 30 and a 45 gallon should be minimal, so if they need the extra capacity I'd pick the larger one.
@ November 14, 2013 11:43 AM in Multi-unit house Electric Radiant Floor or Forced Air/Gas?any way to put tubing and plates up from below?
Radiant heating will require a bit less energy than forced air, all things being equal. You can generally count on a space temp (air) of 3º-4ºF lower, but the BTUs still need to be there to offset the losses.
http://www.eia.gov/neic/experts/heatcalc.xls will help with the math.
@ November 13, 2013 7:55 PM in tekmarwas what I was thinking. If Budget is not an issue, install a Viessmann B2HA and skip the outboard controls. It can manage two mixing valves and three separate ODR curves with the onboard controls.
@ November 13, 2013 7:37 PM in Weil Mclain CGt install with CI radiatorsA properly sized mod/con boiler would require no extra parts and probably burn 20-25% less fuel than the buffer tank and ODR valve with the CGt will. If you elect to skip the buffer tank, probably more like 30% less.
3-way valves with spring returns are available, but then you need an external control (which will cost at least what the iSeries-R does.)
@ November 13, 2013 7:26 PM in tekmarTekmar has a coup;e of options that will manage two mix temps, which I believe is what you are looking for?
@ November 13, 2013 2:22 PM in Weil Mclain CGt install with CI radiatorsYou need a new valve, not the one that diverts DHW. A Taco iSeries-R is probably the least expensive option http://flopro.taco-hvac.com/products/index.html?category=188
With one of these, you would set the boiler a few degrees higher than what you need for the emitters on the coldest day.
Tekmar has several controls which will run a motorized valve and also do boiler reset. If you go that route, install the sensor near the top of the buffer tank instead of on the boiler supply/return. Unless you need over 150ºF, boiler reset will not do much for you.
@ November 13, 2013 2:15 PM in diverter valve for domestic line waterGeo-Sentry will work.
Apollo also makes a 3-way that can be motorized.
@ November 13, 2013 1:31 AM in Weil Mclain CGt install with CI radiatorswhich is sort of the same thing, only backwards -- and with no modulation.
@ November 12, 2013 11:11 PM in Weil Mclain CGt install with CI radiatorsYou almost certainly have a tempering valve, which supplies a fixed DHW temperature to avoid scalding.
What you need is a motorized mixing valve controlled by outdoor reset, which will vary the water temperature feeding your radiators based on the outdoor air temperature.
The buffer tank is to prevent your boiler from short-cycling. It also provides hydraulic separation of the boiler and distribution loops.
@ November 12, 2013 6:15 PM in Weil Mclain CGt install with CI radiatorsand I could not afford a mod/con boiler, I would reconfigure a tank-type electric water heater as a buffer tank and install an ODR-controlled mixing valve on the distribution side of that beast.
@ November 12, 2013 6:11 PM in Quality of help on the WallMost of us try to guide homeowners in the right direction -- often that takes the form of "ask your contractor this" or "insist that they do that."
"Call a pro" is just not good enough when it comes to hydronic heat (of all types.) The state of the industry as experienced by the end-user is quite frankly execrable in many parts of the country. Many of us here own hold licenses and run businesses, but we just hate seeing yet another customer get screwed by yet another clueless installer or repair person. The more informed and aware that customer is, the more likely they are to select a competent installer. I for one do not see this as a threat to my business or the integrity of my profession -- quite the opposite, in fact.
@ November 12, 2013 5:14 PM in Is steam still a viable heating technology for new installs?that the cost and disruption of laying all that threaded pipe would scare off the majority of potential buyers.
@ November 12, 2013 4:54 PM in Galvanized underground condensate return pipingAquatherm is rated for pressure use up to 200ºF. Short term exposure to higher temps is part of that calculation. Commercially-available PP resins melt somewhere north of 265ºF depending on the particular type.
I would not even consider using it on a radiator outlet. At the bottom of a system where the balance of the piping is metallic, I would feel safe specifying it. An up-front discussion with Aquatherm would be required in order to assure warranty coverage for the job, but based on previous conversations I do not foresee issues as long as the system conditions are similar to what I described.
@ November 12, 2013 4:29 PM in Weil Mclain CGt install with CI radiatorsis simple enough to add. Look at the Taco SR501, Tekmar 256, or Heat-Timer HWE-SS for that.
With that boiler, you will be limited to a return temp of 130ºF unless you add another circulator and manage the ODR with a mixing valve or variable speed injection.
What size is the boiler? What is the heat loss for the house on a design day? Those are critical and you do not want to proceed until you know for sure that you have the right size boiler.