Trying to tie in wall panel radiator to existing baseboard run?

lukenurn

Hi,

I'm hoping to tie in a wall panel radiator into an existing zone that heats the main part of our home. Is it possible, and if so, how can I do it effectively? Here's the context:

• The wall panel radiator is 1/2" piping, the existing run is 3/4"
  
• The area where I hope to tie-in is around 1/4 to 1/3 into the beginning of the zone
  
• I just converted an existing screened-in porch to a four season
  
• The door to this new room is accessed through the main living area, which is surrounded in baseboard heat
  
• Because of this doorway, there is a break in the baseboard run that bypasses the door opening below the floor, and up to the baseboard on the other side.
  
• On the other side of the wall (in the 4 season room), there is a perfect spot on the wall where I am hoping mount a wall panel radiator to bring hot water from the pipes under the doorway up through the floor/wall.
  
• I was initially just going to tie in the radiator as part of the loop, however given the drop in size from 3/4" to the 1/2" radiator, I'm concerned the remaining 3/4 to 2/3 of the loop won't get enough heat even though it's all in the same open-concept area
  

What are my options? I've been doing a little research on diverter tees, etc. (link and images below). I usually use push-to-connect. Is a tee system with diverters the best option? If so, which tee's are diverters, what size piping, etc.

https://heatinghelp.com/systems-help-center/diverter-tee-q-and-a/

This image is basically what I'm trying to accomplish. Will this work with 3/4" main and 1/2" radiator run?

Jamie Hall

Is this all in series, or is there a separate feed and return, or is it a monoflow like the screen shot you posted? Makes a BIG difference.

If it's all in series, not a problem. You will have a different head loss, so the flow overall may be a little less, but not much. Separate feed and return, no problem at all. Monoflow? Ah. Now it gets interesting and VERY tricky.

HomerJSmith

This might help.
https://www.caleffi.com/sites/default/files/file/01036_na.pdf

EdTheHeaterMan

Let me first say that the walls in the area or zone that the baseboard heating system is located probably has total glass to total outside wall ratio of less than 25%. There may, or may not be ceilings in that zone that have conditioned space above. This effects the rate at which that zone will loose heat

Compare that space to the new "Solarium" space with no conditioned space above the ceiling, and over 50% glass to wall ratio. Add the fact the there is probably 3 exposed walls compared to 1 or 2 exposed walls in the typical room heated by the baseboard.

Any thermostat for the existing baseboard will not provide a balanced heat for that new room. Conditions like infiltration and solar gain will make it very difficult to balance the new room on sunny days compared to a cloudy, windy day. My suggestion is to make a home run to the boiler room and use a separate zone and separate thermostat for the new room.

From Experience more than once.

Respectfully submitted,

Mr.Ed

pedmec

a monoflo tee system. little harder to control as you real don't know what you wind up with until your complete

or you can add a ball valve between two standard tees and use that to throttle a portion of the loop to the panel radiator.

DON'T PUT IN SERIES WITH BASEBOARD. you will get heat but what you also get is velocity noise. Will drive you crazy. i made that mistake many years ago. you can get lucky if you have a low flow circulator. I made this mistake at my house many moons ago. had a grundfos 15-58 on low speed and still to much noise drove me crazy.

Alan (California Radiant) Forbes

DON'T PUT IN SERIES WITH BASEBOARD. you will get heat but what you also get is velocity noise. Will drive you crazy. i made that mistake many years ago. you can get lucky if you have a low flow circulator. I made this mistake at my house many moons ago. had a grundfos 15-58 on low speed and still to much noise drove me crazy.

The piping must have been very small.

lukenurn

Jamie Hall said:

Is this all in series, or is there a separate feed and return, or is it a monoflow like the screen shot you posted? Makes a BIG difference.

If it's all in series, not a problem. You will have a different head loss, so the flow overall may be a little less, but not much. Separate feed and return, no problem at all. Monoflow? Ah. Now it gets interesting and VERY tricky.

Well from these conversations, I just figured out what series vs. monoflow is. My system is currently all baseboard in a series, so it comes in one side of the baseboard and out the other, then goes straight to the next baseboard (no tees, diverters, etc.), however this zone is all part of one open concept living space so I'm not very worried about heat loss from the early part of the zone to the end (i.e. leaving the last room in the series much colder). I was planning to tie in the baseboard with monoflow setup (similar to the screenshot, except the panel's supply/return are within inches of each other) since the panel radiator would be so early in the zone, I don't want to reduce the overall heating capability of that zone on really cold days (in Wisconsin by Lake Michigan, so gets very cold) by creating a choke point early on with the panel radiator's 1/2" piping. My original plan was to tie in the radiator as a series without tees, diverters, etc., then I considered the piping size and thought to do a little more digging and get some help from you all!

Are you saying this would be a major problem to pipe the radiator in this way?

lukenurn

HomerJSmith said:

This might help.
https://www.caleffi.com/sites/default/files/file/01036_na.pdf

Do these basically act like a monoflow system for the panel radiator, so I can run the baseboard series loop supply in one side of this, and the return out the other to continue supplying the rest of the zone? If so, that's amazing. Unlike my photo I posted, the panel radiator has the supply/return right next to each other, which looks like one of these parts would work.

Would that negate the need for tee's?

lukenurn

EdTheHeaterMan said:

Let me first say that the walls in the area or zone that the baseboard heating system is located probably has total glass to total outside wall ratio of less than 25%. There may, or may not be ceilings in that zone that have conditioned space above. This effects the rate at which that zone will loose heat

Compare that space to the new "Solarium" space with no conditioned space above the ceiling, and over 50% glass to wall ratio. Add the fact the there is probably 3 exposed walls compared to 1 or 2 exposed walls in the typical room heated by the baseboard.

Any thermostat for the existing baseboard will not provide a balanced heat for that new room. Conditions like infiltration and solar gain will make it very difficult to balance the new room on sunny days compared to a cloudy, windy day. My suggestion is to make a home run to the boiler room and use a separate zone and separate thermostat for the new room.

From Experience more than once.

Respectfully submitted,

Mr.Ed

Thanks Mr. Ed.

There is a decent amount of window space, however when we leave the door open from the living area (which I'm proposing to tie into this zone), the general ambient temperature (when our home is set to 68-70) stays around the low 60's even on very cold, windy Wisconsin winter days (most of the wall in this space is a very thick brick as it used to be external, so once it gets to a temp, it holds it quite well). With a space heater on low, we have been able to keep the room at the same temperature as the main living area. It also faces the shade, and we are a half mile from Lake Michigan, so temperatures don't ever swing or get too extreme. We don't need a/c in the room, because we just open the windows. We are lucky if we see 1 day in July that hits 90.

I'm really just looking for a little supplemental heat, not a major supply. The room, ceiling, and floor are well insulated and we don't mind sitting out there with a blanket if needed. I agree that your proposed solution is the most appropriate, however I'm also trying to work off my existing system without a lot of time or expense. Down the road when we get a new boiler (I'm currently milking along an old munchkin T-80 because no one else around here will work on it or knows how), I'll set up the capability for more zones and will hopefully have the money to pay a professional to help.

EdTheHeaterMan

lukenurn said:

I'm really just looking for a little supplemental heat, not a major supply. The room, ceiling, and floor are well insulated and we don't mind sitting out there with a blanket if needed. I agree that your proposed solution is the most appropriate, however I'm also trying to work off my existing system without a lot of time or expense. Down the road when we get a new boiler, I'll set up the capability for more zones and will hopefully have the money to pay a professional to help.

As long as you understand the limitations, then I would use two regular tee fittings 3/4" x 3/4" x 1/2" to connect the panel radiator. Add a full port ball valve between the tee fittings. You can partially close the ball valve to act as a restriction to force some of the water thru the panel radiator

This will be better than one or two monoflow tee fittings. One monoflow fitting will produce some diversion of the flow at a fixed rate. Two will divert a little more flow at that fixed rate. If you get lucky it will be the correct amount. If it is not acceptable, then you are stuck with the bad design and the associated comfort issues that result.

If however, you use regular tee fittings and a valve, you can make minor adjustments without re-plumbing the loop. Just move the valve a little to the left or the right as needed. Once you get it dialed in, Tighten the packing nut to prevent accidental adjustment and remove the handle. I usually hang the handle near the valve on a large paperclip of piece of thermostat wire

I have anticipated your next question. Click on the Spoiler

But my tees will be so close together because the supply and return are on the same side of the radiator, so I don't have room for a ball valve.This is why God invented Elbows!

Hope this helps.

HomerJSmith

lukenurn, Yes, the Caleffi Diverter and isolation valves do act as a monoflo tee. No you don't need tees when you use them. The flow is passed thru the diverter to the next inline heat emitter.

hot_rod could give better advice on the use of these valves.

pedmec

@Alan (California Radiant) Forbes . No. not very small. Standard 3/4 slantfin 30 baseboard. the problem is that the its a 1/2 tappings on supply and return for the runtal radiator. reduction from 3/4 to 1/2 results in increase in velocity at the inlet. @ 4 gpms your gonna go from a 2.9(ft/s) to 6.5(ft/s).

hot_rod

I would go with Ed the man advice with 3 valves
Maybe use a 3/4 globe valve in between the tees. You can be much more accurate with a globe especially when you need to reduce flow quite a bit. Or an official 130 type balance valve🥴

Ball valves closed more than 60% or so  get very touchy to flow, hard to fine tune, and it is not a friendly flow path through a ball valve closed down that much. Kinda like a piece of unreamed copper tube flow path

lukenurn

EdTheHeaterMan said:

But my tees will be so close together because the supply and return are on the same side of the radiator, so I don't have room for a ball valve.This is why God invented Elbows!

Hope this helps.

Is there a recommended distance between each of the tees? I recall it being specific (6" to 12") with diverter tees depending on brand. Not sure if this matters with regular tees.

Also, Homer recommended this earlier in the discussion > https://www.caleffi.com/sites/default/files/file/01036_na.pdf

What is better, the tees + globe valve, or this Caleffi diverter valve?

hot_rod

Without knowing the flow rate, I’d go with 3 valves instead of the H valve. It may not have enough capacity across the bypass portion.

lukenurn

hot_rod said:

Without knowing the flow rate, I’d go with 3 valves instead of the H valve. It may not have enough capacity across the bypass portion.

What do you mean, 3 valves? I was imagining two t's with a globe valve in between like the below image...

hot_rod

Yep, that will work

HomerJSmith

One gets flow when there is a pressure differential. That's what a Monoflo tee or a throttled globe valve does. Adding a panel radiator to an existing circuit doesn't add any more heat energy to the output of the circuit. You are only taking heat energy from the other downstream radiators. The only way to get more heat energy out of the circuit is to increase the flow or increase the fluid temperature. In a mod/con the reduced return temp is a bonus. A conventional boiler a return temp should be above 130 degrees.

A trick that I have used with toe kick heaters is to use a 3/4" X 1/2" X 1/2" tee on each
connection to the panel with 1/2" pipe between the inlet and outlet of the panel rather than using Monoflo tees. I always use a true Monoflo tee rather than the cheapee China diverter tee which add greater pressure loss to the circuit.