Extending a baseboard radiator - Need the return to stay above the floor

[rmcderm313]

Hi All,

Several years ago we extended our breezeway/foyer, almost doubling in size. Most of the added size extends past the foundation and is over an area that is exposed to the elements aside from some lattice. This area is supported up to building code etc, but it as no basement under it like the original part of the area.

The baseboard heater in this room (hydronic system, copper piping) is way too small for the area and the room is freezing in the Winter (maybe not literally but it's uncomfortably cold). Here is a photo of the baseboard in the room..

http://s1252.photobucket.com/user/r...E-41E5-B8DC-E7BAB1B26D4A_zpsjdbcawul.jpg.html

I'd like to extend this baseboard radiator along the entire wall. My issue is that I don't think I should bring the return pipe into the exposed area beneath the extended breezeway. We are in SE Massachusetts and freezing would be a concern. I suppose I could insulate the pipe, but I'm not sure if it could be insulated well enough to avoid freezing issues.

Is there a way, or a baseboard product that allows for the return pipe to travel back through the baseboard unit thereby remaining in the room instead of going through the floor?

Hopefully I've explained my situation adequately. Thanks for any and all assistance.
Rob

 

[rmcderm313]

May have answered my own question by finding this.... This is from the installation manual for this product:

Slant/Fin® Multi/Pak®80 -2' Hydronic Baseboard Radiation For Hot Water 103-401-2

Any thoughts or advice on using this method to solve my issue?
Thanks,
Rob

 

[Sponsor]

 

[Dana]

To do this right you would need to do a room-by-room heat load calculation for the rooms on the zone, and install only the amount of heat emitter than balances temperature-wise with the rest of the zone. If you go hog wild on this room without doing the math it can overheat, going from one extreme to the other. Heat loss is not a function of square footage of the room. This is worth taking the time to get right, since it's a PITA to fix it later. Figure out how many BTU/hr of load you have in the other rooms, and the ratio of BTU/baseboard-length. With the BTU/hr load of the room you're upgrading you can then install a proportional amount of baseboard or radiator output to get reasonable room-to-room temperature balance. Clearly that 3 footer isn't enough, but 20' might be WAY too much if it's going to balance with the rest.

This down & dirty I=B=R type load calculator isn't the most accurate in absolute terms but is good enough for ballparking the radiation from the perspective of temperature balancing with the other rooms.

You can also consider improving the floor insulation in the exposed floor area, and air-sealing the band joists, which are often a major heat leak in cantilevered floors like that. How deep are the joists, and how much (& type) of insulation do you have there?

If you go with cast-iron baseboard like BaseRay most of those have a pipe at the top and another at the bottom, and can be simply looped back. It's ridiculously pricey when new, but can often be had from scrap yards or craigslist for $10/foot, sometimes less. If you go the surplus/scrap route, be sure that the end sections have cast-in legs. They clean up pretty easily, can be lightly sanded and painted to suit.

Alternatively, you could replace the 3-4' of fin-tube with a flat panel radiator or thin-profile cast-iron (again, surplus cast iron is cheap, and easy to clean up). A 24" tall x 40" x 5" deep panel radiator like a Ecostyle B24.40 is the heating equivalent of about 13-14' of pretty-good baseboard. A 40" wide SunRad or Radiant (20" x 40.5" x 5" deep) is the equivalent of 11-12' of baseboard. There are literally tons of the SunRad/Radiant style radiators installed between 1920 & 1960 being scrapped during renovations on houses in RI and SE MA, being replaced by cheap fin-tube, and it's a dramatic step DOWN in comfort(!).

^^Modern sheet steel panel rad^^

^^Burnham Radiant style kneewall & window rad^^

^^Arco SunRad style window & kneewall rad^^

SunRads and Radiants work ~15% better if you give them 1/2"-3/4" of clearance from the wall rather than cut into a wall-cubby. They can be lightly sanded and painted whatever color you like. Typicial craigslist pricing on a 40-50 incher is about $75-100 in good shape, though some people think they're worth more. I picked up 43" & 58" SunRads from a renovator redoing a circa ~1950 house in CT for a whopping $100 for the pair when micro-zoning my house a few years back. They got painted to match the window trim (1920s bungalow) and they look like they've always been there. There were a few other vendors of 20" tall x 5" deep flat radiators, and the output specs are all similar.

 

[rmcderm313]

Wow.... It's going to take me a little bit to digest everything you wrote here. Thanks so much for your help and I will respond with answers to your questions (and probably more questions) ASAP.

I can't tell you how helpful it is to have someone like yourself providing guidance and answers on a topic that is new to me. Well Done!!