Joined on August 27, 2007
Last Post on July 24, 2014
@ July 11, 2014 6:46 PM in Radiant Ray is miaHe is a 10 year old, about 6 feet tall, very over weight, looks a lot like our host, ten years ago, anyways :)
I finally found this pic on my still working Sony Mavica! floppy disc camera.
When plugged in he has a warm, stainless hand shake from the B&G series 100 flow and heat.
I built him in Missouri, he has been spotted in, Utah, Colorado, NY, and PA, at the various RPA headquarters.
If you know of his whereabouts contact ME at the RPA..
@ July 11, 2014 11:59 AM in Getting into mod/con businessI believe the questions and points discusses are in fact on the minds of our customers, home and building owners.
There are so many way to heat hydronically, it's good to have choices. If the products are approved and listed to heat water, and installed in a code like fashion, they should be considered.
Pretty much every water heater manufacturer now has a boiler offering, and some have heat pump, solar and solid fueled offerings.
Oddly, doesn't Canada still approved combined DHW/ radiant with water heaters? .
@ July 11, 2014 11:38 AM in Drain back with evacuated tubesmake sure the tube collector you are considering do in fact drain 100% or you could freeze the headers. I have done a few with the collectors mounted sideways, if the manufacturer will allow horizontal mounting.
That looks like a centrifical pump? which is fine if it can handled the lift and temperature.
Remember those tubes will get smoking hot when drained.
With that in mind water hitting an absorber in the tube at 400F plus will flash to steam.
You could pressurize that loop to drive the boiling point up, 30- 40 psi could be considered.
Or consider a solar controller to limit pump operation at extreme collector temperatures. There are 12 and 24VDC controllers available. That controller could offer additional features, drainback specific functions, data logging, etc.
@ July 10, 2014 7:09 PM in Caleffi (and other) Web-based Controllersand interface with the various loggers has been worked out, no more issues with current versions, that I know of.
Getting them online is still a hit and miss. I think more has to do with the ISP, routers, hand held devices, etc. Finding someone that can get all the technologies on the same page isn't easy, then to understand the solar and water side to boot. Not many building owners have stable, or static IP addresses unless you pay for that or go with a third party service to provide one. That is what throws a wrench in the works. The logger is always searching for the address you programed in.
I hear the vbus.net has cleared up lot of the problems. Your logger talks directly to their server, and you pull data from it. Try a demo at the www.vbus.net sight.
I also came across this chat room for the vbus user, looks like most of the issues and questions are addressed here along with a factory person or two that I recognize. This would be the most current advice I could offer.
Sorry, I don't deal with these enough to stay current on the versions and updates.
@ July 10, 2014 6:57 PM in Hydronic underfloor used to effectively enlarge direct solar thermal mass?is to talk with as many passive home owners as possible. Nothing like living in a passive home for a few years to get a feel for what works and what doesn't. There is a passive home group in the US and a International association or two also.
@ July 10, 2014 10:09 AM in Getting into mod/con businessif the concern is being able to generate DHW on a design heating day, you could priortize the DHW. That is how the mod cons with onboard plate HX operate. Usually stopping a pump or diverting a 3 way zone valve is how they do it. Additionally some have an adjustable time out so the boiler cannot ignore the heat call.
@ July 9, 2014 9:43 PM in DHW configurationeither the heat trap nipples or Sioux Chief Heat Trap loop will eliminate thermosiphon.
Or if you have a recirc add thermostat, timer, and insulation.
I think Carl has it right, your heated water is moving energy dollars from the tank, somehow.
@ July 9, 2014 9:35 PM in Getting into mod/con businessat my house and shop I generate DHW with 5X12 30 plate HX. The shop runs off a large solar tank, 180 gallons. I get a hot shower with the tank as low as 130°F via the plate. Size to a 10° approach on the HX. So at 130° on the "a" side I still see 120° on domestic side.
A Harwill flow switch triggers an Alpha to run the "A" side. DHW up to about 2.5 gpm heats instantly. That Buderus could do that use a 3 way thermostatic to protect from cold return temperatures.
In the winter my 120 Lochinvar Cadet produces DHW with an even smaller plate HX inside, but it does run up to 180°F.
Summer months at the house DHW from a 30 plate HX on a 50 gallon Thermocon buffer. But it does get a solar pre-heat from another solar drainback system.
@ July 9, 2014 9:26 PM in Getting into mod/con businesswe will be forced to buy 90%. Old habits die hard, I'll miss those old cast iron "boat anchors" they served us well. Miss my 78 Ford 250 4X4 also.
@ July 9, 2014 9:21 PM in Looking to make condensate neutralizerBought 3" clear PVC online from US plastics. They sell short lengths. Glued into a 3" plugged closet flange, and a 1" MIP adapter glued up top for the drain out. You can watch it work, if ever you bet bored.
That is about a years worth of work on the limestone rocks.
In the summer I dump my AC condensate line into it.
@ July 9, 2014 7:57 PM in Getting into mod/con businessI'm not a huge fan of a common water heater as a heat source. The small boiler would be my choice.
We had this discussion many years ago at the RPA. Larry Drake the director always wondered why an "H" stamp is such a important feature. Why does a low temperature heat source need to be called a boiler even. Boilers is an old term dating back to steam days :)
If the "heating appliance" can be built safely with all the appropriate LWC, over temperature, no flow, low pressure cut out, gas train safety, etc, why not. Most of these controls are standard on Euro origin mod cons, or the connection is provided for LWC switches for example. Most of the mod cons that came from off shore did not have the H stamp early on and proved to be equally as safe, or safer than H stamped products. The Euro boilers meet some fairly strict standards.
Some of the tank style "boilers" on the market do not have the H stamp, and have adequate protection, like their mod con kin. Maybe it's an entire mod con assembly shoved into a tank? I think my tank style condensor has a vacuum cleaner motor for the inducer fan. Sure is robust.
@ July 9, 2014 7:39 PM in Hydronic underfloor used to effectively enlarge direct solar thermal mass?We did a passive home in Utah many years ago that had black, stamped concrete in the south facing great room. We did what you are considering. t didn't end up moving much energy around as we had expected. We watched it for a few heating season with some simple hour meters.
The cost for the additional controls to allow that, may not have been recovered with any energy savings.
I think you would be better off using the $$ amount on the building shell upgrades, best insulation, triple glazed windows, top quality heat pump brand, etc.
With a super insulated, passive home the energy costs should be very low to begin with. You may see heat load numbers in the single digits for BTU/ sq. ft. The back rooms not seeing that passive gain directly, can still be warmed with some air movement from the ERV or other exchange device, with some planning.
The biggest complaint was overheating. Wakeing up in the morning after a cold night had the slab with a belly full of energy. All that mass needs time to ramp down, it is not a quick responding system, a concrete slab.
If I were to do it again i would look into low mass heat emitters, maybe some radiant floors in the bathrooms and tiled kitchen floor.
Most of those early passive homes in the sunbelt mountain areas had their windows and doors open on sunny days, too much of a good thing can be un-comfortable when it comes to a 90° passive home.
This article may help put some numbers to the question. Thanks to PM Magazine for archiving all this info.
@ July 9, 2014 6:54 PM in Getting into mod/con businesskeep in mind a modern cast iron or copper tube boiler is much different from a 30 year old one, size and mass, ignition system, insulation, to name a few. A 100K cast iron is not that much larger than a mod con these days.
What is the most expensive component to replace on a cast iron boiler? What the most common failure on a mod con? Price a inducer fan and motor, available only with the circuit board attached. A mother board $$?. These are the unknown, or known unknowns that can throw the numbers out of budget quickly.
Not to go back too far, but standing pilot boilers ran troubleefree for decades, some without any maintenance over that life cycle.
I know some contractors only install mid efficiency equipment in the very rural areas where parts availability is slim, and a service call round trip could ring up hundreds in fuel and windshield time, usually requiring two trips. Parts and multiple service calls could ring up a grand rather quickly.
Keep in mind the elements out of our control, low gas pressure, ever changing fuel BTU content, obselete OEM parts, all realities. These are some of the common realities of 90% equipment. Ignore PVC venting for this discussion :)
At the end it is what is best for the individual customer, and their expectations for on-going yearly maintenance.
Many of us here embrace modcons, but we are able to service and repair our own stuff, the consumer doesn't always have that option.
@ July 9, 2014 11:08 AM in Radiant coolingwater be the same a desalinated water. Able to be treated for drinking?
@ July 8, 2014 10:25 PM in Low flow air solar wallsand certifying performance of air (transpired) collectors now. Some some actual performance and durability data is available. Looks like your brand is one of the listed.
@ July 8, 2014 10:13 PM in Old Vaillant boiler info neededLooks like they still maintain an office there.
@ July 8, 2014 3:12 PM in Ecodrain gets US building code approvalthe GFX brand started in 1986, must be plenty, thousands?, of them installed.
Larry has one in his place, what maybe 10 years now? Something to be said for no moving parts or electronics.
Again, like anything, in the right application that would be an excellent ROI, considering maybe 800 bucks installed.
Wonder what that 25 lbs of scrap copper will be worth in 20 years or so :) should it wear out.
@ July 8, 2014 11:12 AM in Peer review please...the concept of storing energy in the ground. Really a GEO system IS solar energy. Cave dwellers in Colorado lived in a hole in the rock facing south. I doubt they had much snowmelt square footage, however.
My question is how a surface slab could store or exchange energy better than well or trenches into the constant 55°f earth temperature.
The insulated slab will hover around ambient except for sunny summer months. The bore holes or deep trenches always have around 55°F to offer.
The surface slab sounds more like a large air to water exchanger that you can park on :)
Sure there is some DHW pre-heat potential, not nearly what a manufactured collector could produce, however.
We all know and acknowledge that energy storage is the holy grail. The whole world is looking for the best most efficient option, especially Europeans where todays fossil fuel price is $8.56 per gallon.
So far this year I have read about energy storage in compressed air, latent HX materials, flywheel inertia, all sorts of batteries, it's all being considered.
Best I can tell a modern HP with the latest refrigerants and high efficient ECM motor technology, tied into a earth loop or pond loop is as good as it gets. If you want heat, cooling and DHW at the flip of a switch, as most do, not under the suns fickle terms.
I think we all agree on the HP as the key, the discussion seems to be slab on grade, or reach deeper into the ground for the energy exchange.
I'm onboard for trying ME's concept, I just wonder how a residential pilot project, ME spoke of, without a huge summer DHW or heat load will pencil out? Nobody will spend $50,000 or more to save $300.00 per year?
Currently they are capping off NG wells with a glut and low prices. If you have the $$ to install snowmelt, pay the NG costs so the oil guys can make a decent living and the radiant contractors have work. Isn't it mostly the oil folks building those custom homes with large snowmelts in the mountains, currently? Or their financial guys.
With the US becoming the largest oil producer, better melt snow before the world comes shopping for that NG, prices may go up.
Certainly the bright folks at NREL would have some knowledge in these areas, I'd like to hear their thoughts. All this is calculate-able, the data exists at places like IGSHP and NREL and many other Energy Universities across the world.
@ July 7, 2014 11:38 PM in Peer review please...lying horizontal, what is the efficiency of that? Look at the performance slope on an unglazed collector, which a driveway or parking lot slab could be considered. Although an unglazed collector would have the absorber directly in the sun. The slab would have the absorber tubes 2-4" below the direct sun. So probably less efficient.
An unglazed collector has great performance compared to flate plate or evac tubes when the ambient and fluid temperature are close. Once the ambient drops 10- 20 below the fluid the unglazed goes in the toilet, performance wise. Not to mention wind across the slab or vehicles parked over it in a commercial parking lot.
So first consider the cost of tube and insulation, labor etc to install lets say 10,000 square feet of slab. How much would you bid to tube and insulate 10,000 sq ft of slab the was to be poured? Concrete and labor to install is already covered, just the cost to turn it radiant. Divide that by the efficiency of that slab collector across 12 months.
I'm thinking that dollar amount spent towards flat plate or evac tubes would give you much more energy, and perform in the cold months to 120- 140F, whereas the slab would not exchange much energy below 80°F ambient.
Here is a performance graph, notice how an unglazed collector drops as temperature drops. Once the ambient is about 20° cooler than the fluid, you performance is completely gone. unglazed collectors, or slabs are good for providing 80- 85 pool water temperatures in warm climates.
That slab would make a great heat dump, but you have no solar thermal to dump :)
Someone good with solar simulation could model 10,000 square feet of un-glazed collector with 10,000 gallon of storage and see what the SF is. Then model that same load with flat plate or tubes and compare the required square footage and see how the costs work out.
True the PV is less efficient compared to thermal collectors, but there is ALWAYS work for the pv, unless you have a consistent all day DHW load all year you thermal numbers will never pencil.
Some thoughts for that load year around water parks, huge daily DHW and indoor pool loads. Prisons, plenty of them around, most over crowded. Predictable daily DHW loads.
NRT Rob has some pretty good, actual data comparing PV to thermal on one of the solar threads, but not unglazed thermal.
@ July 7, 2014 9:28 PM in Ecodrain gets US building code approvalgood move. May be the best bang for your fuel saving dollars, these drain HXers.
@ July 7, 2014 9:16 PM in Fill, vent air, purge, 3/8" PEX, 25ft elevation changeis it a radiant loop? There may not be a good method to add a high point vent.
You would want a good air vent and hydroscopic cap for extra protection, if it is a panel radiator, for example..
What is the total elevation from equipment room, expansion tank location, to thr highest point in that upper loop?
Adjust the system fill pressure to assure the highest point in the piping has 5 psi. That will help assure air free operation.
For example, 3 stories, maybe 27' from mech room to upper level 27 X.433= 11.6 , add 5 psi for a 16.6psi. call it 17 psi fill pressure.
The expansion tank needs to be sized for the system capacity, plus the operating pressure of 17psi
The expansion tank pre-charge would need to be adjusted to match the fill pressure you decide on. Here is a link to a expansion tank sizer.
@ July 7, 2014 3:52 PM in Cleaning radiant tubingA micro jetter is what we need to develop!
Something with an 1/8" flexible line that could pull itself through several hundred feet of pex. Heck doctors push tubes through our veins and can take pictures and do some sampling even.