Replacing cast iron radiator with smaller one

Alan (California Radiant) Forbes

Make sure the cabinet layout allows for proper air movement to and from the radiator. Cold air is pulled into the bottom of the radiator, hot air leaves vertically from the top. If the path is blocked, air movement stops and the heating is retarded.

pecmsg

i’d like to add to raise the outlet above the countertop. You don’t want food in objects falling into the opening.

again that cabinet will have to be removable, that radiator will need cleaning at worst if you develop a leak you’re going to have to get to it.

TerrS

So there is another option but you might lose some BTU's so it depends on if your kitchen is cold or not. I mean you can't beat a cast iron radiator, my house has slant fins and even with 185 degree water they are only about 600btus per foot. So when I did my Kitchen remodel 8 years ago I needed a better solution. They make a buderus panel radiator that is very efficient.

https://www.supplyhouse.com/Buderus-3-42424-Model-21-24-x-24-Hydronic-Panel-Radiator

They come in many lengths but I think 24" is the tallest. I put a 3' and a kick under my sink. It's works well with a 1 pipe system as there is a diverter valve that runs about 40/60 thru the radiator and still 185 degrees

Depending on the model they are 2.5 or 4" wide. It also has a valve on the end you can adjust if needed..

Geosman

Interesting project! I could not help adding my two cents. This is obviously an older home. The walls are stone or brick and the floors are likely diagonal 3/4 pine with hardwood on top. The vinyl floor will likely have 1/4" luan sheet on top of the hardwood to allow for the vinyl floor so…..unless you plan on pulling up alot of floor and starting over, I am very pessimistic that radiant from below the floor will be effective as the thermal resistance through all these layers of flooring will be more than most radiant systems can overcome.

If focusing on radiant floor heat I might suggest checking the floor thickness and composition. There are several companies that make aluminum clad retrofit radiant panels that can be set on an existing floor or if an older floor is removed down to the original or floor joists to accept new subfloor and radiant panels. The radiant panels are typically 2 foot by 4 foor and can be cut to size. If planning for a tile floor simply add backer board and tile or if installing a floating floor, it may go directly over the radiant panels so that you can get the full benefit of the radiant warmth. If checking various sources my favorite is Warmboard R for retrofit projects. The Warm/board R is 13/16ths inch thick and uses 1/2" PEX tube, but there are other sources using 3/8" PEX tube that are as little as 1/2 - 5/8" thick to help provide the radiant effect.

Radiant floor heat will need to operate at a reduced water temperature so if piping from the existing supply and return fittings below the old radiator, it is essential that you use a dedicated variable speed pump such as a Grundfos 15-58 pump with internal check valve and a hydronic system thermostatic mixing valve, (Caleffi 521 or equivalent), to reduce the boiler temperature down to at least 100 to 120 max temperature feeding into the radiant floor circuit.

Operation of the pump for radiant floor heat might be managed using a wirless thermostat and pump control. Hydro-Smart seems to have a good working setup for a wireless thermostat and pump relay.

https://www.hydro-smart.com/products/wireless-radiant-thermostat?variant=48123551842586&country=US&currency=USD&utm_medium=product_sync&utm_source=google&utm_content=sag_organic&utm_campaign=sag_organic&srsltid=AfmBOoq4ORmSw7Ne3hCuORh71BojqiPQvCmnTWk9r7ANm2Gi7AIrmtpgZOU

If the floor surface is to remain as-is with the remodel, I favor the toe-kick heater. Beacon Morris K120 which can easily provide 11,000 BTU operating on 180 degree water. As with most all older homes the exisitng radiator was likely sized to heat the kitchen with the window cracked open for ventilation air. I seriously doubt if you need 9,000 to 11,000 BTU unless you will also be cooking with the window open. To allow independent control of the toe-kick heater, I suggest using the same pump, thermostatic mixing valve and thermostat control I described for radiant heat, the controls can be set to operate the fan coil at a reduced temperature, (likely in the 140 range), to more closely match the actual heating requirement in the kitchen and the variable speed pump will auto adapt to manage the needed flow rate and pressure drop across the toe-kick heater and mixing valve. The pump wattage will be a small fraction of the wattage that might be consumed by a traditional fixed speed circulator pump.

lvrailroader_2004

Cast iron radiators were designed to be placed in front of windows so that the cold air coming off, or through, the window would mix with the hot air coming out of the top of the radiator, causing the warm air to "tumble" across the room as it rose into the air. That's what makes cast iron radiators so efficient. Without that cold air behind them, their efficiency drops hugely. Just a thought.

falconseven

I am a retired general contractor for 25 years. I recently renovated a bedroom into a walk-in closet in my 200-year old house. The existing radiator was large (see picture). After considering room is 800 Cf or 100 Sf, walls are insulated R15, floor is insulated R19, floor is 3/4 T&G boards+1/4 plywood with inner seams taped and parameter seams taped and caulked, new Andersen window, and further insulated by clothes, I decided I could downsize the radiator without heat loss. The risk, the room will take longer to heat up. To reduce this risk I screw a piece of sheet metal to the wall in back of all my radiators, including radiators with radiator covers.

The existing radiator went from a 25 inch high 10 section cast iron radiator to a new 19 inches high 4 section cast iron radiator from castironradiatorsusa.com. Assembling the radiator fittings was pretty easy because the new radiator comes with specifications sheet. Easy for you to let a plumber install. I think the radiator was about $279 with truck shipping. Be careful, make sure you have someone strong enough to carry the new radiator from the delivery truck to the spot where the radiator will be installed.

Mad Dog_2

That's a gorgeous radiator. As dabrakeman said, remove, sandblast, powder coat....it needs to have its dignity and beauty showcased. Add a TRV if better temperature control. Mad Dog