Add toe-kick in series loop or lengthen baseboard length or both?

[DIY Todd]

I am a DIY’r with some plumbing experience, but my plumbing vocabulary/knowledge is pretty basic. I have already successfully added cast-iron baseboard myself. I have help that is more experienced available if necessary.

Here is my primary issue. I want to add built-in cabinets on either side of my fireplace. To do so, I need to remove 5 lf of the existing cast-iron baseboard. As it is, the system keeps the space adequately warm, but on very cold days, like 20F and lower, it seems like the boiler is called often and the system has a hard time keeping the space at 68F without running quite frequently. I am concerned that if I remove 5 lf of baseboard it will make the problem worse and the system will have a hard time maintaining a comfortable temp. Here are the options I am considering:

- Put toe-kick heaters under both cabinets that will be put in.

- Make up the 5 lf of lost baseboard by adding 2 ft onto one of the existing baseboard lengths that is staying, and possibly 2 ft onto another. I will still end up with less baseboard than we currently have. Also, to do this I have to take apart and subtract/add to each of the 3 lengths of baseboard.

- Combo of option 1 and 2 which is the most expensive and most work.


Some details:

- The loop runs in a series

- The boiler is in the basement directly below the room

- The ceilings are 15’ high at the ridgeline sloping down to 8’ in living area

- The main living space is 385 ft^2

- The adjoining kitchen, is 140 ft^2 with no additional heat. The temperature feels the same as main space (open concept).

- A ladder leads to an adjacent unheated 2nd floor, loft area of 108 ft^2 of space which also does not get colder than the main space

- I have extra baseboard available so I don't need to purchase the extra lengths to add to existing lengths.


Questions

- Toe kick heaters would be served by 1/2” while the existing zone is served by 3/4” copper. If I go with the toe-kick option and I put them into the loop in parallel using mono-flow tee’s will their addition add to the overall heat in the room and compensate for the loss of 5 lf of cast iron baseboard? Or, will their 1/2” supply/return, even putting them in parallel with mono-flows, just become an expensive, but negligible addition to the system? I’m concerned that the added resistance will offset any gains by adding them.

- Am I better off getting back the baseboard lost by adding to the other baseboards?

- Doing both toe-kicks and adding to the existing baseboard may be the best option, but the most work, cost, and aggravation. I’d rather not take that route if options 1 or 2 is predicted to be sufficient.

- To add to the one length of baseboard, I’d be swapping out 5 ft of 9” x 2/5” cast-iron for 7-ft of 7” x 2” cast-iron. Although the second baseboard will be longer, it actually comes out to less cast-iron baseboard volume wise. So, is this even making the situation better on that length? Is thinking about the amount of cast-iron baseboard volume wise instead of length accurate to the way they work?

- Or, should I just reduce the existing baseboard by the 5ft and hope for the best? Perhaps whether or not it’s 26 ft of baseboard or 21 ft of baseboard the outcome may be the same as it may be more of a insulation/heat loss issue?


I greatly appreciate any and all advice on these matters.

Todd

 

[Jadnashua]

As long as the boiler can keep the temperature up, regardless of how long it is running, it is fine. It's more efficient if it actually runs constantly. On/off cycles hurt efficiency and longevity. Unless the system can modulate, that won't happen except on the worst case design day.

 

[Sponsor]

 

[Dana]

Toe kicks are a noisy abomination and a last-resort solution. The 9.5-10" cast iron baseboard is good for 3.4' EDR (equivalent direct radiation) per foot, so you're talking 17' EDR total that you're looking to replace.

The 5" x 20" tall Sunrads or Burnham Radiant et al cast iron rads are 1' EDR per inch of width, and come in 2.25" wide sections. Every foot of baseboard can be replaced by 3.4 INCHES of Sunrad. So an 18" wide (8 section) Sunrad would more than cover the missing 5' of baseboard, a 31.5" (14 section) would nearly double it. It was pretty common to mix and match Sunrads & cast iron baseboard from the 1920s through the 1950s, and they can often be had pretty cheap on the used market. This big 'un can replace about 15' of 10" tall cast iron baseboard, in just a bit over 4' of length. They're to be found all over L.I.

This is about the size you need to replace just 5':

With a used rad it's worth hooking up a garden hose and blowing 50 gallons of water through it to remove most of the grit & scale & rust flakes out of it, or even giving it a vinegar rinse, for an hour with a small pump prior to hooking it up to your system (especially those previously used for steam.) But they are easily repainted, and are pretty bulletproof.

 

[DIY Todd]

As long as the boiler can keep the temperature up, regardless of how long it is running, it is fine. It's more efficient if it actually runs constantly. On/off cycles hurt efficiency and longevity. Unless the system can modulate, that won't happen except on the worst case design day.

Jim D.,

Thank you for the advice. That's good to know about the running often and on/off cycles.

Todd

 

[DIY Todd]

Toe kicks are a

noisy abomination and a last-resort solution. The 9.5-10" cast iron baseboard is good for 3.4' EDR (equivalent direct radiation) per foot, so you're talking 17' EDR total that you're looking to replace.

The 5" x 20" tall Sunrads or Burnham Radiant et al cast iron rads are 1' EDR per inch of width, and come in 2.25" wide sections. Every foot of baseboard can be replaced by 3.4 INCHES of Sunrad. So an 18" wide (8 section) Sunrad would more than cover the missing 5' of baseboard, a 31.5" (14 section) would nearly double it. It was pretty common to mix and match Sunrads & cast iron baseboard from the 1920s through the 1950s, and they can often be had pretty cheap on the used market. This big 'un can replace about 15' of 10" tall cast iron baseboard, in just a bit over 4' of length. They're to be found all over L.I.

This is about the size you need to replace just 5':

With a used rad it's worth hooking up a garden hose and blowing 50 gallons of water through it to remove most of the grit & scale & rust flakes out of it, or even giving it a vinegar rinse, for an hour with a small pump prior to hooking it up to your system (especially those previously used for steam.) But they are easily repainted, and are pretty bulletproof.

Dana,

Good idea and good to know about the less-than glowing review of toe-kicks. I know they work, but sticking with cast iron has its appeal to me. I was considering swapping out one of the baseboards for a more vertical cast iron like you mentioned.

Thank you,

Todd

 

[Bcarlson78248]

I installed a toe kick heater to replace the old cast iron radiator when we renovated our kitchen, and I would give it mixed reviews. Its mounted under the kitchen cabinet, and the fan kicks on whenever the water gets to the set point (I think that is about 105-110) degrees. There are two speeds for the fan, but you have to just pick one. It turns the fan on automatically when water hits the set point, but will not switch fan speeds.

My boiler system has a 100 degree minimum set point, so when heat kicks on it takes a little while for water to circulate and hit the toe kick temp set point. This means I start to get heat out of the cast iron radiators quicker than the toe kick. Then it kicks on the fan and you get good heat while the circulator is moving hot water. As the circulator kicks off and water temp goes down, the fan kicks off because its tube and fin design has very little mass and it cools quickly. However, the cast iron radiators have enough mass that they continue to heat for quite some time after the water stops circulating.

Bruce

 

[Guy48065]

How do you feel about the noise?

At my lake cottage I replaced 2 6ft door walls with 9 foot versions. Now my fin/tube baseboard heaters are a trip hazard and need to be removed. I'm considering toe kicks in the floor in front of each door wall but will look for another option if they are noisy.

 

[Bcarlson78248]

I have the Myson that is similar to this one - http://www.mysoncomfort.com/static_files/int/media/downloads/WHISPA III KICKSPACE SUBMITTAL 2016.pdf
My fan is set on low speed and it very unobtrusive in the kitchen. My Sharp microwave makes more noise when it runs than the toe kick fan.

I put a large cut-out in the floor of the sink cabinet, and used small metal supports across the corners so that I could just drop the floor back into place. That gives me access to the water and electric connections if I need to work on anything.

Bruce

 

[Guy48065]

That's encouraging. I've never read any complaints of excessive noise and since mine would be in the living room near the TV--it was a concern.