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Simply Not Enough Baseboard? (22 Posts)
Simply Not Enough Baseboard?Hello Everyone,
After having a contractor replace the single steam system with three separate hot water systems in my 3-family three years ago, this is the first winter where the third floor apartment is actually empty. The tenants since then have been the young, twenty-somethings with tight budgets, and therefore, most of them have kept the thermostat set very low, usually high 50's to low 60's.
Now that it's empty (thank goodness) and I'm the one responsible for the gas bill this winter, I decided to seal the 5 year old double-glazed windows and six skylights with plastic film. Might as well, right? The house was built in 1948, and is located in RI. Most of the exterior walls are uninsulated, and the cathedral ceilings (70% of the apartment) are insulated.
Well, with the temperature hovering around the low 40's, I've noticed the heating of the small apartment (only 650-ish square feet) is VERY uneven, as the bedroom, bath and den (on on side of the house) get very warm, and the other side of the house, the kitchen and living room stay very cool.
The living room and kitchen are open to each other, and have a 10' cathedral ceiling with four skylights over them. The kitchen and living room are the last rooms on the heating loop. There is 4 feet of baseboard in front of one of the windows in the kitchen (which is 97 square feet total), and 14 feet of baseboard in the living room (which is below the two windows. There is one 11' wall (an uninsulated knee wall against attic space) without any baseboard at all.
The bedroom, which is 10x11 and has 7' ceilings, gets extremely warm with it's 20 feet of baseboard and hot water fresh from the boiler.
My questions are, should I add another 11' of baseboard to the knee wall in the living room? Also, should I reverse the flow (as in swap the supply and return pipes at the boiler) so that the warmest water will be supplied to the living room & kitchen, and then on to the bedroom (which has the most baseboard?).
Should the contractor be doing these modifications, or is three years too late for any corrections to his work?
I've attached some pictures of the piping arrangement.
Some things to check...3 years is too long to go after the contractor....
Now... before doing anything, check the water temperature differential ....you may simply have a weak pump or even air in the lines...if you are over 20 degrees differential then you have other issues...figure out why...
Also, you maybe able to balance the heat some by simply closing the louvers on the baseboard in the rooms it enters first...
The kitchen may be a bit short in heat but usually that is compensated for, by the extra cooking heat....
Before making any changes, I would check this stuff out first...
ZoningHave to ask where the thermostat is and if this apt is one zone? Whe you say the liv and kitchen are cool is that in comparison to the other rooms? There is plenty of board based on what's in your post. Problem may be the thermostat placement. Only way to solve this may be to zone."The bitter taste of a poor installation remains much longer than the sweet taste of the lowest price."This post was edited by an admin on October 29, 2011 5:35 PM.
One ZoneThe apartment is on one zone, like the other two apartments. The thermostat is located on the wall between the Den and Bedroom. It is right next to the bathroom door.
I thought about relocating the thermostat to the wall opposite, which would place it on the other end of the hallway, and next to the arch into the living room. The problem is, that would simply make the bedroom hotter than it already is. It would be (what seems like) 5-10 degrees warmer than what the thermostat would be reading. There is that much difference in the temps between the bedroom and kitchen/living room. In this situation, I don't think zoning the system up would be practical considering the challenges in routing the piping...
I've tried closing the louvers in the bedroom and den, and it simply doesn't change much at all. The bedroom, even with the 8' section closed, throws way too much heat, and by the time the thermostat is satisfied, the living room & kitchen are chilly.
I should also say that during the system conversion I had an electrician wire up a ceiling fan in living room at the very peak of the ceiling to keep the warm air at the top down lower. The problem is, there is no warm air up there... The baseboard doesn't provide enough heat to collect at the top of the ceiling.
Now, if I turn on all 4 burners on the gas range, the heat rises right up and the fall will push it down... But I don't want to have to heat the apartment with a gas range in order to get even temperatures...
I have tried bleeding the system, and there's no air in the lines. The air separator and vent valve are fine. The boiler (each apartment has it's own boiler) has plenty of capacity, it's a 84K BTU gasser. The hePEX lines are 3/4" all the way through. I haven't checked the differential. What's the best way to check supply and return temps? Can I rely on the boiler gauge for supply temp, or do I have to measure upstairs?
Any thoughts on reversing the flow, putting the living room first on the loop, or would that not help much?
Reversing Flow...Would only make a slight difference. You need to add the extra the 11 feet in the living room and I would also add another four feet in the kitchen. That would make the amount of radiation more proportionate for each side.Bob Boan
You can choose to do what you want, but you cannot choose the consequences.
That's DoableI can definitely add that 11 feet in the living room, and behind the range there's a false section to hide the PEX. I'm sure another section of finned tube can be placed in there.
The baseboard is Hayden. If I can't find Hayden baseboard to match, should typical Slant/Fin and a Slant/Fin inside corner trim match up with the Hayden?
While the problem could be flow rates or circulator-related, or what not, it just seems nonsensical that the bedroom, with about 900 cubic feet of volume, would need 20 linear feet of baseboard, while the living room & kitchen with nearly 2500 cubic feet only has 18.
Heat LossBased on your drawing and photos thisnisnwhat Income up with. This is by no means accurate but should be in the wheel house. Using the Haydon Chart calculating a 2Gpm flow rate board will put out 596 btus's a ft with 180 degree water.
Kitchen 4,384.= 8' board
Living Room 7,395 = 12.5' board
Den 3,698 = 6.2' board
Bedroom 4,104 = 7' board"The bitter taste of a poor installation remains much longer than the sweet taste of the lowest price."
ThanksThanks for the calculations. I used FloPro and came up with these figures:
Living Room - 7900 BTU/hr
Kitchen - 4700 BTU/hr
Bedroom - 5700 BTU/hr
Den - 3600 BTU/hr
Bath - 1500 BTU/hr
So they are quite similar, and (at least in the living room), the amount of radiation satisfies the calculated heat loss. So where does the problem lie? I haven't checked my differential yet, that might give some clues...
My circulator is a Taco 007-F5, by the way. The gas boiler is a Superior SG-5, rated at (DOE) 84 MBH. I'm running 18 PSI cold.
Loop Heat ing FAQAfter searching around a little, I found an excerpt from on of Dan's books, with Loop Heating FAQs.
I'm surprised how many of the FAQs applied to this very situation. One side hot, the other cold, etc.
I guess this is a common issue with loop systems, and it's all about the proper calculations when the system is designed.
I never thought about wrapping sections of the finned tube with aluminum foil to prevent air flowing through them. That might help me balance the bedroom a bit better.
I did a measurement of the supply and return temps at the boiler, and my Delta-T, with 180 degree supply water was 36 degrees F. This seems a bit steep and only reinforces the idea that there is too much baseboard in the bedroom which is starving the living room of the hot water it needs.
I'm still wondering, though, about swapping the supply and returns. It seems like one of the easiest solutions in this situation. The hot water would supply the living room and kitchen first, and then flow to the bedroom, and den, which have oversized radiation as it is. I'd think that would make up for the loss in water temperature if they become last on the loop... Any ideas?
PexYou mentioned that pex was ran. What size and how many feet?"The bitter taste of a poor installation remains much longer than the sweet taste of the lowest price."
3/4" Wirsbo hePEXThe plumbing for the system is all 3/4" hePEX. First, the supply runs about 35 feet from the boiler in the basement to under the 1st floor closet. Then in runs another 20 feet straight up through the 1st and 2nd floor closets. Then a total of about 185 feet in the actual apartment, including 3/4" finned-tube and PEX, then back down the 20 feet, and over the 35 feet again. This gives a grand total of
3/4" Wirsbo hePEXFirst, the supply runs about 35 feet from the boiler in the basement to
under the 1st floor closet. Then in runs another 20 feet straight up
through the 1st and 2nd floor closets. Then a total of about 185 feet in
the actual apartment, including 3/4" finned-tube and PEX, then back
down the 20 feet, and over the 35 feet again. This gives a grand total
of 295 feet of piping.This post was edited by an admin on October 30, 2011 8:17 PM.
HeadThat is 6' of head alone without counting fittings, valve, etc. Your issue may be the pump. Couldn't say 100% but I would investigate more. Sure there are no kinks anywhere? Taco 007 will move 2gpm at just a little more then 9' of head. Are you running 100% water thru the system?This post was edited by an admin on October 30, 2011 8:38 PM.
Add to that 29 ElbowsInteresting... I've removed the covers from all the baseboard to clean the finned tube, and I haven't seen a kink in any of the PEX, but I did noticed many plastic 90-degree PEX elbows which were used around all of the sharp corners as the baseboard follows the corners of the walls.
... After doing a quick count, there are 18 3/4" plastic PEX 90-degree elbows, and 11 3/4" copper 90-degree elbows.
The circulator is a Taco 007-F5.
PumpThere lies your problem. I'd replace the pump with a Taco 00R 3 speed or Grundfoss UPS15-58 3-speed. Is the apartment zoned with the 007 or is the 007 a system pump?
Head CalculationThe Taco circulator is the one and only circulator in the system.
Now I just did a head calculation for the system, and with 2.5GPM, listed as the minimum GPM for 3/4" PEX to keep air entrained, I'm getting 11.9 ft of head. With 3.5GPM, I got 21.9 ft of head.
Now I don't want the GPM to be too high, or the bedroom will be WAYYYY too hot, right? Now, the 007 is on the return side of the system, pumping toward the expansion tank. After replacing the circulator, should I swap the supply and returns, and place the circulator on the supply pumping away from the expansion tank instead?
Thanks for all the help,
NickThis post was edited by an admin on October 30, 2011 9:55 PM.
GpmIs the flow rate you need to deliver to get the btu's. It comes from you heat loss.
gpm = btuh divided by delta-t x 500
2gpm = 20,000 btus which is the apartments heat loss.
What I am hearing"1948" "un-insulated attic knee wall" etc. Drafts and poor insulation won't go away even if you fix the pumping problem. If all the piping is pex, it should be fairly easy to add/remove finned element. I would add some heat near the dormer window in the false enclosure etc. You could remove some fin tube from the bedroom.
I would look at draft proofing and insulation first. An area this small should "balance out" especially in mild weather even if the radiation is unbalanced.
Is the finned radiation installed correctly ? with the "opening" aiming up/down? and not turned 90° ? if you know what I mean. I have seen this a few times
BillHe is already running a 30 degree delta-t adding more board is just going to widen it.. His problem is the pump. A 007 is only good to 9ft of head at a 2gpm flow rate. Heat loss says he has enough board, pump can't move the gpm required.
ThanksWhile the house is old, and that knee wall _is_ quite cold, drafts aren't an issue. I've caulked gaps around window casings, sealed electrical outlets, etc. The envelope is pretty tight, it's just that there is a thermal break missing from most of the exterior walls.
And, now that you mention it, I do remember seeing a section of baseboard in the living room that had the plastic anti-squeak strips facing out TOWARD me rather than being on the bottom of the fins like the rest of the apartment. These Haydon units have fins that are bent 90 degrees on the last 1/8" or so of the metal. I'll have to double check the orientation of the fins to see which way is correct, with the bent tabs up/down or in/out. Maybe I'll have to re-solder the finned tube to realign it, if its off 90 degrees.
If the head on the 007 isn't sufficient for the amount resistance in the piping system, wouldn't the bedroom be cold as well? What 's actually happening inside the pipes? Is the flow of water slowing down as it gets to the living room because it can't make it past all the elbows?
@Chris, So I am using that formula first to calculate the GPM, and then using the head formula to determine the size of the circulator, right?
NickThis post was edited by an admin on October 30, 2011 11:18 PM.
Pump CurveNick, yes to calculate the flow required use the following formula. A standard hydronics baseboard system runs on a 20 degree delta-t.
GPM = Btuh divided by (delta-t x 500)
You heat loss is just about 23,400 btu based on your post.
23,400 divided by 10,000 = 2.3gpm flow rate
Your head is 11.9ft so you need a pump that can move 2.3gpm @11.9ft head for this zone. Because this is a system pump we need to calculate the gpm based on the heat loss of the complete system, ie all the zones. If you didn't do a complete heat loss of all the apartments take the net btu of the boiler and plug that into the btu portion of the formula. If its an 80,000 btu net boiler then you need the pump to move a total of 8gpm.
Head is not comulative. If the pump can overcome the highest head in the system it can overcome all. You can be assured this apartment has more the likley the most head. So now you need a pump that can move 8gpm @ 11.9ft of head. If you look at the pump curves attached you can see the proper pump would be a Taco 00R or 0012 or a 009. I'd go with the 00R. I've also attached the curves for the smaller 00 pumps. Is that return 1"?
This post was edited by an admin on October 31, 2011 8:11 PM.
Thanks ChrisBingo! Bill was on to something when he asked about the finned tube being installed in the correct orientation. All 14 feet of baseboard in the living room was installed with the bent tabs oriented up and down, preventing air flow through the fins. It was easy to bend the first section of the fins to the correct orientation, but the 2nd section is a bit tougher. I'm going to try again tomorrow after the pipes cool to room temp, perhaps the metals will contract. After a test run, that first section of baseboard which is in the correct orientation is throwing much, much, more heat than it ever has.
Chris, I actually have three separate boilers. This 80 MBH boiler only supplies the 3rd floor. 1st floor (my apartment) has the converted-from-steam Weil-McLain Gold Oil Boiler, and the 2nd floor has a Laars Oil Boiler.
The return for the 3rd floor is 3/4". It's all 3/4" from the outlet of the air scoop all the way to the circulator. My uncle is a service man for an oil company so I will see if he has any spare 00R, 009 or 0012's in his van. He's going to be cleaning the boilers this week, so I will talk to him then.
NickThis post was edited by an admin on October 31, 2011 10:07 PM.