old home retrofit emitter design

CC.Rob

Need some help, please.



I'm late to the game on this one.... 1100sf main house, built late 1800s, two floors. Cast iron baseboard on monoflo system, single zone, installed early-mid 20th century. Interior walls were stripped and the whole house was icynene-ed. Haven't done the heat load but there's plenty of radiation. The boiler is a well-maintained ~2003 Burnham Revolution RV-4 that will stay.



An 800 sf addition is going up. Two floors 400 sf each. Upstairs master BR. Downstairs living and open kitchen that joins main house. Addition is all 2x6 framing, with icynene insulation, excellent windows.



Haven't done the heat load, but am already told that emitters in the addition will be fin-tube due to budget constraints. Ugh.



Not sure how to approach zoning. Considering leaving original house as single zone. Might need to mix down for that and use hotter water in the addition. Considering the addition as a single zone. Not a lot of wall available to overradiate, and certainly no way to size the emitters to comparable to the overradiation that exists in original house.



Will have to see how the load and radiation calcs turn out. Might be that using high-output baseboard will get design water temps down sufficiently so that whole house can run one temperature. (Probably dreaming -- there's tons of CI baseboard).



Will be adding ODR and indoor feedback, most likely simple with tekmar 260 and indoor sensor somewhere in the addition.



Have already suggested they look at IAQ issues with HRV/ERV, but not in my purview.



Thoughts appreciated, particularly on zoning and mixing strategies. Thanks.

CMadatMe

Try Using

Radiant panel baseboard. The price is comparable when you take out the base moulding that the carpenter is going to has to install and it will work very well with your existing system. E-mail me if you would like more info as we cannot post PDF files here.

NRT_Rob

well hold on

radiant panel baseboard is significantly weaker than fin tube. If the problem is that he's trying to jack up the output per foot, that would be exactly the wrong direction to go in.



really he should be looking at more like Runtals, but budget will nix that in a hurry probably... unless it kills the need to add mixing. It should, and it should work better on a single reset curve. Runtal and a TRV or thermostat would be my vote, skip the mixing, sized for whatever you need in the cast iron section.

CMadatMe

Not necessarily

Heat hasn't done the heat loss and maybe the room layout  will allow him to use it. It was a recommendation for another product. I'm sure the carpenter is putting in base trim. This is the same size as trim.

NRT_Rob

sure it's small

it's just very weak. if he doesn't have the wall space for adequate fin tube (as he says), he definitely does not have the wall space for those products.

CMadatMe

Space is a question

he needs to give more information on. Could it be the height that's a problem. What's stonger or weaker have anything to do with it if you can overcome the heat loss that he hasn't done yet. While the panel board only puts out 205bts at 180 degrees unlike fin-tube at 590/600 you can reset it a whole heck of alot better and have better zone conrol (meaning comfort) than the fin-tube. I still don't believe that there is no base moulding going around the perimeter of the room. I would like to know what total footage of base moulding is going in the room. The panel board will work much better with his exisiting system the fin-tube.

CC.Rob

some of the numbers

Existing structure design load is 18.5k. It is overradiated by a factor of 2.7.



Addition design load is 11.3k. Achieving the same 2.7 overrad factor would require some honking big panel rads (e.g., Mysons, which are readily avail. around here).



We'll see.



Thanks for the input guys.