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  1. #1
    Join Date
    Jan 2014
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    Default Alternatives to FHW radiator during kitchen remodel?

    Wanting to remodel my kitchen this year but still up in the air about heating. Currently there is a single cast iron radiator against the exterior wall under a narrow countertop. I'd like to place full sized cupboards/countertop down the entire exterior wall, so this is an issue. A friend of mine put in an electric heat mat under new tile and likes it, and since I'm planning on replacing the worn out hardwood with tile, that is an option. What I imagine as the best fix is to remove the radiator and somehow use the same water supply to heat a baseboard that could be in the toe space under the entire span of cabinets. Has anyone ever seen anything like that or have ideas about potential issues? The way I imagine it working is some cast iron to copper conversion, then plumbing a loop under/between the cabinets and back, so no other plumbing need be disturbed. Thoughts???

  2. #2
    Join Date
    Sep 2012
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    Boston
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    Default Re: Alternatives to FHW radiator during kitchen remodel?

    more economical than an electric mat under the tile would be to put in a toe kick heater under one or two of the cabinets utilizing the water supply that you would have used for the baseboard. just running slant fin under the cabinets is not a good idea.

  3. #3
    Join Date
    Jul 2009
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    Default Re: Alternatives to FHW radiator during kitchen remodel?

    I appreciate your desire to do whatever you can on a diy basis, and this is to be encouraged; however, the two most difficult rooms to heat in a home are the kitchen & the bathroom--the reason being that both rooms have very limited floor space due to confined spaces and the cabinets, & other components that in most cases take up most of the available floor space.

    I strongly suggest you consult the Yellow Pages under "Heating Contractors" & find a local pro who is experienced in modifying hydronic (hot water) heating piping arrangements; if he's good at what he does, he will consider any one of 7 or 8 options to come up with the one that will best suit your particular kitchen's heating needs-----before the pro arrives, you should be doing your own calculations on the 7 to 8 points below, so that you'll be ready for the contractor when he arrives; modify the dimensions below to coincide with your own kitchen & calculate the heat loss for your kitchen-----all heating components, rads, baseboard, kickspace heaters, etc. are rated according to the calculated size for your particular kitchen.

    He will take a heat loss calculation for the kitchen by taking the square footage & multiplying by a heat factor; let's say a 12' X 12' kitchen needing 40 btu/hr/sq.ft. = 5760 btu/hr (the heat output in BTUs/hr to keep your kitchen warm), and then calculate the output of your present radiator to see if that can be used, assuming space is available & the heat output calc for the rad is high enough (below, antique rad calc); or perhaps decide that a kickspace heater hidden under one of the kitchen cabinets in the 5760 btu/hr range would be best; or suggest that a sub-floor HW radiant loop as a take-off from your existing boiler would be best; or perhaps a strip of floor vectors might do the trick; another consideration is at what point is the heat piping takeoff from the boiler supply line???; many kitchen & bath rads are "at the end of the line" on the boiler piping circuit & thus produce the least amount of heat (hw supply at its lowest temp, because the LR & BR are heated first), & thus the kitchen piping circuit would best be served by its own separate zone valve controlled by its own T-stat (often includes bath if adjacent to kitchen)

    The least costly option would be if the heating man can use the present rad, if it's big enough, & is not in the way & can even be put on a separate zone with a t-stat; kickspace heaters are sometimes a good option, but MANY OF THEM ARE NOISY & DON'T PUT OUT ENOUGH HEAT, so make sure you are satisfied with the install if this is what is eventually done---the advantage to having a contractor do this is that if there is a noise or low heat problem with the kickspace, the contractor will come back & replace the unit with a better one free of charge ; a sub-floor radiant loop with its own t-stat is often a good option, but is component & labor-intensive & expensive.

    Hold your fingers to the supply piping of your present rad when the t-stat is turned up & see if you can feel the pipes heating; if you don't have to take your fingers off the pipe when the rad is heating up, you don't have enough heat in that piping circuit to heat the kitchen (the rad could be at the end of the line in the heating circuit).

    The Beacon-Morris site has a lot of different components that can be used in a kitchen, like floor vectors & kickspace heaters; at the site,click onto "residential products" & "additional residential products" ; Antique Plumbing site will help you calculate the heat output in BTUs/hour of your present rad (click onto Ask Fran option); the YouTube site will illustrate how radiant floor heat is installed.

    If you DO decide to diy, you will do a much better diy job if you do some of the suggested calculations before buying any expensive components & doing the work of the install.


    http://www.beacon-morris.com
    http://www.youtube.com/watch?v=jAU1AexTgso
    http://www.antiqueplumbingandradiators.com
    Last edited by Pelton; 01-02-2014 at 10:14 AM.

  4. #4
    Join Date
    Jan 2010
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    Northern Virginia
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    Default Re: Alternatives to FHW radiator during kitchen remodel?

    I second the idea of a hydronic toe-kick heater. I replaced my cast iron kitchen rad with one, and it heats just as well; since it's under the sink cabinet, the warm air on my feet is appreciated. Mine was from Myson I think, like this:
    http://www.houseneeds.com/heating/fa...FYl9OgodtngAyQ
    The only difference is the fan noise, which the rad didn't have,obviously.
    Casey
    Remove not the ancient landmark, which your fathers have set.

  5. #5
    Join Date
    Dec 2013
    Location
    Montreal Canada
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    115

    Default Re: Alternatives to FHW radiator during kitchen remodel?

    Just so that you know design temp for a cast iron rad is 110 degrees f.
    Design temp for a copper fin rad is 180 degrees f. what that means is that you will never be able to heat the kitchen by replacing a cast iron rad with a copper fin one. i would go electric heating with in-floor or under cabinet force air electric heater. also i would use a separate t'sat , kitchen are some times very hard to control with the stove over heating the room when in use

  6. #6
    Join Date
    Aug 2008
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    69

    Default Re: Alternatives to FHW radiator during kitchen remodel?

    Quote Originally Posted by bill shack View Post
    Just so that you know design temp for a cast iron rad is 110 degrees f.
    Design temp for a copper fin rad is 180 degrees f. what that means is that you will never be able to heat the kitchen by replacing a cast iron rad with a copper fin one. i would go electric heating with in-floor or under cabinet force air electric heater. also i would use a separate t'sat , kitchen are some times very hard to control with the stove over heating the room when in use
    I completely disagree with a number of statements in this post: "design temperature" is completely misleading when speaking of rads or other HW convectors & usually refers to a locality's lowest expected low temp when designing an overall heating system; however, a cast iron rad can operate with a water temp of anywhere between 80 degrees F and 200 degrees F, depending on if the given system is radiant heat or standard HW heat in the range of 145 degrees F to 165 degrees F; likewise, there is no set "design temp" for copper fin convectors, which can & do operate between 140 degrees F and 200 degrees F & higher; it's also wrong to say that one will never be able to heat a kitchen by replacing a CI rad "with a copper fin one"(I assume the reference is to copper fin baseboard??), when in fact the heat output of copper fin baseboard is calculated per linear ft. at a certain water temp between approx 150 degrees to 200 degrees, with a per linear ft. output of between 360 btu/hr to 700 btu/hr; there is also HIGH OUTPUT BASEBOARD available which can put out over 1000 btu/hr per lin.ft.; thus approx 6 ft. of std. baseboard @ 180 deg. F water temp would be able to provide sufficient heat in a 12' X 12' kitchen; however, I agree with MLB that baseboard would not be a good idea due to the damage it would sustain due to foot traffic & the way heat is distributed from the "chimney effect" design of BB, as well as the stated lack of space considerations experienced in nearly all kitchens.

    Although I'm not sure I agree with Bill's other offerings as to a solution to the kitchen heat, I welcome them & he is to be thanked for the post.
    Last edited by von_steuben; 01-04-2014 at 04:13 PM.

  7. #7
    Join Date
    Dec 2013
    Location
    Montreal Canada
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    115

    Default Re: Alternatives to FHW radiator during kitchen remodel?

    design temp on a rad is the temperature required that rad needs to give the heat output as listed in the capacity chart. a cast iron rad will start blasting out heat when the water temp in the rad reaches 110 F by 140 the rad is running a 100% capacity where the copper finn rad has not even started to, produce heat. the home owner stated that the existing rad is cast iron. I have seen this problem many times in my life. I refer you to the following web site
    http://www.expressradiant.ca/pdfs/pr...ing_how_to.pdf

    at 110 f the rad starts to put out heat of 30 btuhs per square foot by 180 f it is putting out 170 btuhs per foot now lets look at copper fin rads
    http://www.slantfin.ca/documents/404.pdf

    They do not even list water temp outputs until the water temperature is 150 by then out cast iron rad is blasting out
    150 btuhs per square foot .
    never mix cast iron rads and copper finn rads the rooms with cast iron will be very warm and the rooms with copper finn rads will be cold.

  8. #8
    Join Date
    Aug 2008
    Posts
    74

    Default Re: Alternatives to FHW radiator during kitchen remodel?

    Quote Originally Posted by bill shack View Post
    design temp on a rad is the temperature required that rad needs to give the heat output as listed in the capacity chart. a cast iron rad will start blasting out heat when the water temp in the rad reaches 110 F by 140 the rad is running a 100% capacity where the copper finn rad has not even started to, produce heat. the home owner stated that the existing rad is cast iron. I have seen this problem many times in my life. I refer you to the following web site
    http://www.expressradiant.ca/pdfs/pr...ing_how_to.pdf

    at 110 f the rad starts to put out heat of 30 btuhs per square foot by 180 f it is putting out 170 btuhs per foot now lets look at copper fin rads
    http://www.slantfin.ca/documents/404.pdf

    They do not even list water temp outputs until the water temperature is 150 by then out cast iron rad is blasting out
    150 btuhs per square foot .
    never mix cast iron rads and copper finn rads the rooms with cast iron will be very warm and the rooms with copper finn rads will be cold.
    ---------------------------------------------------------------------------------------------------------

    I agree with von_steuben & Pelton & find shack's above post even more misleading than his 1st comments, not only in regards to his confused, myopic way of calculating heat output of the different convectors, inappropriately mixing the Canadian metric system with the US Standard system, but then relying on referenced charts that have no bearing on the actual heat output of the convectors under discussion; we haven't even yet obtained the rad dimensions, HW temp, & kitchen sq.ft. from the OP & shack is completely ignoring these variables, as well as discarding the possible use of other convectors he is not familiar with.
    Last edited by brewster; 01-07-2014 at 09:18 PM.

  9. #9
    Join Date
    Jan 2014
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    2

    Default Re: Alternatives to FHW radiator during kitchen remodel?

    Thanks everyone for the input. The kitchen is quite small, ~130 sq.ft., and is located on the south side of the house. It's interesting to hear that the normal circulation pattern is to heat the bathroom and bedrooms first, in this home the kitchen and dining room get hot first then bedrooms and bathroom rad last. Maybe the flow was reversed when the boiler was replaced in 2005? That's kind of a joke. Either way, I like the idea of the toespace heater and think it is a great place to start the conversation with a heating contractor (I have no intention of DIYing this one). Thanks for the suggestion and the links.

    With regards to mixing cast iron and copper, my upstairs was finished ~85 years after the home was built and it has no issue with copper slant fin heating the space even if the boiler is turned down below 150F. I appreciate your input Bill, but have to agree that your interpretation of the charts and logic on copper vs. cast iron is incorrect. Copper (and aluminum, the fin material in your chart) have much higher thermal conductivity, meaning like electricity, heat also passes more readily through those materials compared to cast iron. Heat in equals heat out plain and simple, and there is no minimum heat required to make a copper pipe hot. In fact it does state on your chart that for lower water temps you should consult a second document for the output, not that it won't work. Thermal conductivity aside there is something to be said for cast iron; the high thermal conductivity of the aforementioned materials means they will quickly transfer the energy of the hot water into the room and hold onto very little of that heat themselves. I actually prefer the heavy cast iron rad because it is still hot 40 minutes after the boiler has shut off and the water is no longer circulating.

    For conversation sake, I did get in and measure the rad this weekend, it is 29" tall (actual coil length), 19" wide and 6.5" deep, and has 8 coils (4 tubes on each coil) Not as big as I thought it might have been. In the early fall and spring I set the boiler at 145F, but with the recent attack of the polar vortex I've bumped it up to 165F with good results.
    Last edited by AspiringDIYer; 01-07-2014 at 09:34 PM.

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