Heating Help

not a constant

@ May 10, 2010 6:05 PM in Standby losses

pete, surely you remember your differential equations class?

 one time while studying I plotted the room temp vs time in a typical FA heated house.   the rate of temp fall in the room was amazing non linear.    even at the 4-5 degree differential, nonlinearity was very noticeable. 

that said, an average is easy to take and "good enough" for any type of rule of thumb or "standard "

effected by,

wind- air flow through flue
water temp
ambient temp

but you all know that !

 just sit in the basement for an hour and see how long it take to cycle,  you need to measure water temp too.    your measurement will be as good as anyone else's.

no insulation?

@ May 8, 2010 8:00 PM in Big pex or Little pex

No pipe insulation?

i think 4 lines would work.

I agree

@ May 5, 2010 11:48 AM in Standby losses

that does seem pretty high, like heating an extra 100 -200 gal per day at 70F rise, just to maintain 40 gal of water?

this a cartoon car?

@ May 4, 2010 5:28 PM in Hydronic powered car....

I've always known hydraulics to require cooling systems??  even the snowcat that grooms the local ski trail at 12 mph needs hydraulic cooling.

I too have wondered why hydraulic motor per wheel isn't used more, lot of times there's a good reason though.  

but it is an interesting idea.

lacking

@ May 4, 2010 5:18 PM in MOD/CON MANUAL VOLUME I

what i see lacking in manuals, is a more comprehensive operations explanation.

timers/ time-outs the machine uses, limits, when limits are reset. fault data tables......

if you have a good understanding of its operation, you really don;t need diagnostics, which, always tend to be poorly written, and really are hard to write!

I'd like to see the machine program sequence.

according to slant fin:

@ May 4, 2010 5:11 PM in Standby losses

7-12 degrees per hour.  I also found 2.5% heat loss per hour......

http://www.slantfin.com/documents/406.pdf

I'd still like to know, flue loss compared to all around skin loss.

I've measured and calculated water heater efficiency at 70%, not including standby.

not so fast, part 2

@ May 4, 2010 9:36 AM in Standby losses

ok, lets look at this closer.

internal flue, 3in in dia.  and heated by the pilot.  delta T maybe 30F?  125F water, pilot heated air, say 95F ? just convective lose here.   I will try to measure temp of the flue.

that "thing" inside the flue really isn't attached, at least tanks I've taken apart, that "thing" comes out easily, so I'd guess it has little effect on conducting heat away.  seems to be there to disrupt flue gas laminar flow.

outside tank , much larger surface area than inside.  older tanks maybe 1.5-2 in fiberglass. delta T, summer or winter? my basement usually was 45F in winter, so call delta T 125F - 45F or 80F.

still think jacket lose is negligible?  I think its the other way around.

do a heatloss

@ May 3, 2010 6:35 PM in Standby losses

take an actual tank, figure surface area, find out R value of tank insulation and there you have it!

sounds like leak

@ May 3, 2010 2:01 PM in Viessmann boiler doesn't like sunshine

sounds like a leak to me.

Is there an auto feed on the system?  maybe some weird solar thermal expansion is causing a leak in the house..

pressure is dropping cause the system volume appears to be expanding, as in a leak.

lost the common

@ May 1, 2010 11:10 AM in Electrical Problem

sounds more like somewhere you have lost the common return.

take a long wire and connect it to a known ground, then connect that to your meter and start measuring voltage here and there.

you could also have lost your ground connection too.  or a real poor one causing voltage drop.

ADDED:

or you have 2 problems, a short to ground by a device and a floating  ground, so when you ground the ground, you see another problem.

prefect window project

@ April 30, 2010 2:06 PM in heated window question

I do have a customer wanting a bay window in a breakfast nook, the ones where the bay is a seat.  a 3x4 ft heated window there would be the perfect ticket, being this is considered the wintertime breakfast area.......

jp

flat panel rads act like

@ April 29, 2010 9:53 AM in most efficient piping of HW rads: "TIBO"

some panel rads have vents like baseboards, so I could see where you would get a little more heat out if the top is hotter than the bottom.  this would help the convection currents up through the panel.

Hmm a trick question?

@ April 28, 2010 7:30 PM in heated window question

are you saying you factor in weight of a structure when you do a heatloss?

you had me going, I was thinking of a building empty, then one filled with water, how would they react???   but mass internal to the structure should not effect heatloss of the skin.

colder temps would be more interesting.  but a hot box, cold box it should be the same.  don't you still have cold night temps? with no mass, an hour should tell plenty.   face it up and use nighttime cooling :)  those night time clear sky temperature depressions I measured sure were interesting to see, but now they make prefect sense, thanks for bringing up the topic years ago!

you got me interested, I should go look in the junkyard for old grocery store freezer doors.

jp

interesting question

@ April 28, 2010 1:29 PM in most efficient piping of HW rads: "TIBO"

I wonder if they are looking at a constant circ application of tradition on/off situation?

i could see thermal  siphoning helping out in an on/off control system.

jp

how about "we the people" becoming smarter?

@ April 27, 2010 3:15 PM in Chinese Drywall Fiasco

ask where products come from, ask for locally made products at the same time?

I love the chinease sea food cause people around here won't eat it, I get it from the store FREE and feed it to  the dogs .

be proud, be strong, stand up for yourself and your family.

duct losses & PEX losses

@ April 27, 2010 2:27 PM in Forced Air vs Radiant In-Floor

interesting Steamhead.

it spoke about duct heatloss conductive, that sounds the same as  PEX loss or supply line loss.  this has been an old agurement around here, that a losses in supply line cancel because they are in the structure.  I always disagreed.

but if you count conductive heatloss down the duct, you have to count heatloss down the supply line.

the articles seems to point to poor design and  installation, good article all the same.  I'll re-read it , but it didn't seem to talk about efficiency of a properly running system, they have ecm motors too now.

lets compare apples to apples.  the Wall has seen its fair share of poorly operating and not operating radiant systems. 

got numbers guys????

@ April 27, 2010 9:56 AM in Forced Air vs Radiant In-Floor

eric,

have you Actually measured temperature differences from floor to ceiling on FA?

the numbers might surprise you, it has something to do with the "forced" in forced air.

steamhead, seems the FA efficiencies are pretty high these days? I read a comment by hot rod that suggests they are pretty even.  i generally trust his comments.

yes i agree duct losses can be high, but isn't that why some guy invented "duct tape"?

radiant is nicer, but I really haven;t been in a FA house and said "oh my god" this is so uncomfortable.   keep in mind we should be talking about a highly insulated house with new construction.

comfort??

@ April 26, 2010 6:06 PM in Forced Air vs Radiant In-Floor

well for starters, comfort is in the eyes of the beholder.......radiant is nice, FA is fine too, depends on whats truly important to you.  many here think radiant is the only form of comfort, a little biased.  myself, i prefer a wood stove hands down.  

a lot depends on your floor coverings too, nothing beats radiant for a tile floor, but if you like carpeting and big rugs, don't bother putting heat in the floors.

think about passive solar, use some free heat from the sun.

you should experience radiant for yourself before making a decision.   then if interested, find a contractor and get a quote.

I see no real pros and cons, they are both JUST heating systems....... for me there are no pros and cons to eating ice cream, but for some people there are.

  Eric, can you document this 20-30% savings over FA?  that's a big number.

your choice!

@ April 26, 2010 2:50 PM in Forced Air vs Radiant In-Floor

which do you prefer?

don;t care? hot air will cost less.

want a dollar figure?  pick a number out of a hat.........  whats the cost difference between a good car  and a cheap car ? everyone will tell you something different.

jp

too simple?????????

@ April 26, 2010 12:34 PM in heated window question

that too simple ?   seems after all a insulated shell is just a heat sieve, and measuring wattage in is about as easy as it could be?  though I would make the boxes thicker to greater offset glass losses compared to foam loses.

looks like with the heat flux sensor you need to make many measurements across the glass and do averaging.

how many systems you got out there working?

i saw the pictures of you place, long wall of heated glass, whats the total wattage draw on a 20F day?


jp

nightime sensor

@ April 24, 2010 7:00 PM in calculating nighttime radiant cooling

mark,

years ago you wanted a sensor to detect this.  ever find one?

seems to me just take the differential between a surface temp pointed up and the air temp.

not sure what good it would be for?

jp

backwards maybe?

@ April 24, 2010 5:17 PM in Aquapex in radiant system

more O2 can dissolve in cooler  water than hot .  we have all seen this, just in the opposite direction , open a cold beer then a warm one, which ends up on the floor?  so cooler water will can hold more O2.

of course warmer temperatures speed reactions, and rusting is a reaction.......


jp