A little help on what you probably consider a basic issue...

BigV

Hello all.  I’m looking for a little help on my heating system.  I’m looking at adding a second zone to the basement.  I’ll try to stay brief and to the point.  I searched the wall, but didn’t find a clear answer.  If it’s there please feel free to reference the appropriate thread.  Thanks in advance for all your help.



Home: 1954 construction, 975 sq ft main level, finishing 750 sq ft basement

Heating: One-pipe system (B&G monoflow diverter tees) with fin tube baseboards for main floor (1 fin tube baseboard next to water supply in basement).  It appears the diverter tees are on the supply side, which is contrary to what I understand, to be best practice.  Boiler is a Burnham P-205-A-WNI, 130,000 BTU installed in November 1991.  Both burner and circulator start on call from thermostat.



I’ve had three heating contractors stop by to provide an estimate of the work.  I know it’s not a large house, but I would like a little more control over room temps, so in addition to heating the basement, I’ve asked about adding TRV’s to some or all of the baseboards.  The reason for this is that I would like to turn the heat down in my bedroom (65-68F), but have the bathroom and our children's room warmer (72-74F) and there are no dampers on the baseboards.  I would also like to add an outdoor rest.



All three contractors have suggested creating a second zone for the basement and run the two zones with zone valves.  I like the idea of heating the basement and main floor separately, but still would like more control over the upstairs.  None of the contractors liked the idea of using TRV’s.  Two were unfamiliar with the B&G monoflow system and only use TRV’s in multi occupancy situations.  The other said TRV’s became popular in the 70’s but they’ve had a lot of problems with these "spring valves" and have basically replaced all their TRV’s with electrical zone valves.  Also I was told that these old diverter tee systems are a headache to bleed air out of.



I have a couple questions:

1)  Am I crazy for wanting more control over the heating system in such a small house?  I love the heat, but it does get pretty toasty in the bedroom with the thermostat set at 68F, but not real warm in the rest of the house even though the bedroom is last on the system.



2)  Are TRV’s a bad option here?  Should I just be happy to have two separate zones with setback thermostats and outdoor rest?

 

3)  I have two guys who will only quote copper and one guy who says PEX is the way to go, is one better than the other?  I assume copper will cost more, but does that make it better?



4) To have TRV’s I understand the circulator would have to run constantly.  If this is

correct, will I see a jump in my electric bill?

 

I’m willing to pay for a good system and quality work, I

just need to make sure I’m getting the best system for my dollar.  Any help is appreciated. 

 

Thanks,

V

Gordan

So...

1) You're not crazy, but do you want more control or simply more comfort/balance? The former can be significantly more expensive to attain than the latter. For instance, you can improvise a way to reduce the output from the baseboard in your bedroom, such as wrapping a length of the element in aluminum foil or improvising a damper, which would decrease the output to your bedroom without affecting the overall flow. And it would be C-H-E-A-P. You can use these kinds of silly tricks (restricting the output of your baseboard in easily reversed ways) in order to establish a new balance for how the various rooms in the house should be heated and, as long as that balance can remain relatively constant, perhaps you don't need complicated controls to obtain comfort.



2) a. TRVs and diverter tees can mix, but not easily. Because of the hydraulic properties of diverter tee circuits, any kind of valve that throttles the flow along either a branch or the main will also increase the total pressure drop and decrease the flow of the circuit, and therefore negatively affect the output in other branches. TRVs do not require constant circulation nor do they require outdoor reset. TRVs are not particularly convenient if you want to change the temperature in the space for different times of day.

b. May I ask what you're expecting to get from outdoor reset? Not suggesting that it's a bad idea, just want to make sure that your expectations are realistic, because it would not be trivial to implement with your boiler.



3) Copper is not better per se, but for a high-temperature system it might be preferrable to PEX. If you are using PEX, then PEX-AL-PEX would be a better choice. It has a coefficient of thermal expansion that's close to that of copper (and 8x smaller than regular PEX) so expansion noises as the tubing heats up would be less likely. Proper installation is key with any kind of pipe or tubing.



4) Outdoor reset, not TRVs, results in longer circulator run times. Yes, this would increase your electric usage, moreso during milder weather when your circulator would typically run less. This doesn't make it not worthwhile, but it is a consideration.

BigV

Making sense...couple more questions...

Gordan,



Thanks so much for the reply!  I see what you mean when you differentiate between control and comfort/balance and I am definitely interested in comfort/balance.



1) So with the foil does it matter if I have the shiny side out or the dull side out?



2) a. Sounds like the best option is to skip TRV’s on my system and stick with your “silly tricks” for comfort!



b. I was excepting to save on my utility bill with an outdoor rest.  Sounds like I may be wrong sense:  cooler water temp = longer circulator run time = higher electric bill (does this offset any gas savings?)



3) So does my high water temp system need copper pipe (170F) or is PEX-AL-PEX a suitable option?  Is copper worth a thousand dollars more than PEX-AL-PEX?  I just want to make sure my system will last for years to come.



4) I live on the boarder between climate zones 6 & 7 (cold & very cold) does outdoor rest make sense or is it not worth it?



A couple other questions that have come up:



5) On my current system, are my B&G diverter tees installed correctly on my main floor system?  I didn’t find the red ring I read about.  On the up baseboard the monoflow tee is on the supply side and it has an arrow on the tee with the word “return” pointing back the way the supply came from (see attached picture).  The tee on the return side from the baseboard is a standard tee.  Seems like the system has always worked, but I just want to make sure it couldn’t be working better.



6) My current expansion tank is a steel tank and is not water logged, do I need to “up grade” to a diaphragm style tank?



7) And finally is my taco circulator pumping away?  It’s on the return side just before entering the boiler (see attached pictures).



Thanks again for all the help!

Gordan

Couple more answers

1) No. You're not using its reflective properties here, you're just using it to block airflow around a portion of the fins on the baseboard element. I suggested aluminum foil because it can take the heat.

2 & 4) Outdoor reset may not really help much with your utility bills. It's primarily a comfort thing: it takes advantage of the fact that your baseboard, if it's properly sized for the coldest day, is oversized for any milder days. Its purpose is to deliver heat on a more constant, less on/off basis. It CAN save a good deal of money in combination with a high efficiency, modulating/condensing boiler, which is not the kind of boiler you have, IF you have an excess of baseboard. But, as mentioned, it causes the circulator(s) to run a greater portion of the time.

3) PEX, PEX-AL and copper will all last a long time. All are good options when installed properly. PEX has its advantages, but a sloppy installer could turn those advantages into a liability - creating dips and bends in tubing that can lead to trouble with air bleeding, etc.

5-7) How are you determining which side is supply and which side is return? Sorry, having issues seeing the PDFs.

Charlie from wmass

check your radiators or elements

some mono flow systems had screw driver balancing valves. also they are prone to air blockage a bit more than direct piped systems. Check for air in the colder rooms heat emitters.

BigV

starting to come together...

Gordan & Charlie,



Thanks for all the help



On diverter tees:

I did a little more searching and it sounds like the diverter tee is normally installed on the return side of the baseboard with the return arrow pointing toward the return and therefore if you install it on the supply side of the baseboard it needs to be installed with the return arrow pointing toward the supply.  Did I understand that correctly?  If I have that correct then I think my tees are good.



I was determining the supply based on the direction arrow on the circulator and on the installation manual for the boiler I found in the “appliance folder” the previous homeowner kept. (I use to take it for granted that the divert tee plate with an arrow and the word “return” meant that that was the way the system flowed.  And it seemed right because our room has always been the hottest in the house.  So that reinforced my thought that the system flowed to our room first not last as is the case).  The supply for my boiler I believe is the top connection.  The lower connection with the Taco circulator would be the return side.  Is this correct?  I’ll try to attach the pictures again in a different format.  I had just saved them as a pdf to reduce size and I added a couple notes to the picture of the diverter tee.



As far as air in the system.  I have seen the bleed valves on the return side of the baseboard just before the pipe heads back into the basement.  I've never tried to release air, but I guess it couldn't hurt.  I was listening to the system heat up this morning and wondering how you tell the difference between air in the line and pipe expansion.  The noise I hear sounds like a small quiet gurgle or quiet, rapid rain drops on the roof.  Doesn't seem like it lasts and I've always just chalked it up to expansion.  And speaking of air, should my system's 1-inch main line be pitched or is this just for steam systems?  Seems flat, but maybe there's a slight pitch.



I think I’ll wait on the outdoor rest and see what this year is like with the second zone and use of foil for comfort help.



Thanks again for all the help.  I've tried to attach the pictures of my boiler and one diverter tee.  On the diverter tee picture, the supply from the boiler is from the left, return to the system is to the right and the arrow on the tee says "return" and is pointing to the left (back to supply).

Gordan

See it now

Funny, your system and mine have a lot in common. My distribution piping is cast iron and my diverter tees are correctly installed on the return risers, though. (Also: my fin-tube elements are recessed in convector boxes under windows.) I say correctly because diverter tees on the supply side create more pressure drop along the main. On the return, there is a combined back-push on the main and pull (via venturi effect) from the return. How much this matters in the big picture view... probably not enough to sweat it (apart and back together.) Also: yes, your circ is on the return, and no, it's not pumping away from the tank, but that's another thing that your system and mine have in common. It has not been a source of any problems in my case.



I agree with Charlie: the first step is to verify that what you've got is ship-shape by bleeding it and making sure that all the shut-off valves are fully opened. Then you can worry about tin(foil)kering with the output, starting at the element closest to the supply and proceeding downstream.

BigV

It's nice to know we have similar systems....

Gordan,



Thanks for all the tips you and Charlie have provided.  It's good to

hear that we have similar systems (gives me a sense of relief to know

these systems are still out there).  I'll get some stuff together to

bleed my radiators/emitters this weekend and do some research.  Just

start at the one closest to the supply and work my way down opening and

closing valves with a towel and pan to catch water (simplified)?  Then

I'll starting foiling!  If you think I need to know anything else just

let me know.  I'll probably have more questions. 

Gordan

Just one thing...

The valves that you see are probably shut-off valves. They are not used for bleeding, but to stop flow through that branch. These, you should fully open everywhere. Then there should be a little stub of pipe somewhat above the level of the horizontal tube with all the fins on it, and this should have a little fitting on it with a tiny hole and a slotted set screw. That's called a bleeder, and you open it up with a flathead screwdriver of appropriate size. Try not to strip the screw head. You're correct, bleeding should proceed in the direction of the flow, starting with the branch closest to the boiler supply. You undo the screw a little bit and basically listen and watch. You're done when there is a steady drip drop of water from the bleeder hole, uninterrupted by sputters of air.



Here's the thing: everything you thought you knew about which room gets too hot and which room doesn't will probably change if you actually had air, or if the shut-off valves were partially or fully closed, so give yourself some time to figure out what the new situation looks like before you do any further corrective action.



If you have any doubts about which thingamabob on the baseboard does what, post pictures.

BigV

I guess I shouldn't be throwing the word valve around...

Gordan,



The bleeder is the only item on the radiators/emitters that I can see (no shut-off valves).  I was wrongly using the word valve when talking about the bleeder.  Also, I guess there's another little difference between our systems, looks like the bleeders on mine don't bleed with a flathead screwdriver, but some type of square head (unless I need to do a more detailed look, I just took a quick look this morning at the bathroom radiator while trying to get myself and the little guy ready for the day).  I posted a couple pics below, not sure if you'll be able to see the bleeder real well.



Another thing, what's the best way to clean between the fins?  I was thinking a q-tip, time, & a vacuum cleaner (maybe an air compressor).



Also, based on what you say about your system and the diverter tees on the return side I understand that you're saying mine or ok on the supply just not ideal, is that correct?  I was wondering if when the boiler was replaced if they just switched the supply/return sides, but technically that should still work and nicer for the bedrooms I suppose since the hot water goes to the kitchen and living rooms first.



Have a great Friday!

Jean-David Beyer

best way to clean between the fins?

I do not have the answer. I have a dehumidifier whose evaporator is just some tubing: no fins. And it is a pain between the back pockets to clean even that. I clean the front row of tubes, but it is impossible to do the rest. So I don't. I cannot get at the condenser tubes at all. I forget if they have fins or not.



In May 2009, I had two pieces of Slant/Fin Base/Line 2000 installed. It ran all last winter, and the beginning of this winter. It does not seem to need cleaning, but I assume it will some day. I think I will try my tank type vacuum cleaner with a small brush on the end of the hose. I do not know how well it will work.