Heatloss

mattyc

I’m doing a heatloss for my basement apartment to figure out how much baseboard I really need to heat the place...there’s a small utility closet in the apartment with an oil fired thermodynamics boiler outing out 100,000 btus. I forget how much I should subtract from my heatloss or baseboard requirements do to the massive amount of heat put out from this room (the boiler is in a 6x4’ enclosed room with a slotted door that is being used for makeup air...not the perfect setup but I’m just renting so I know most will say I should bring air into the room from the outside but that I can’t do unfortunately). Thanks all.

Jamie Hall

Hardly the ideal setup, as you say.

I would think, off hand, that the jacket losses from the boiler might well be adequate to heat the apartment all by themselves -- unless it's a big apartment.

You can do a heat loss calculation -- Slant/Fin has a very good calculator on their web site -- but the real question is... are you warm enough as is? And how is air getting into the place to replace that used up by the oil burner?

HVACNUT

No, it's not the perfect setup.
As a matter of fact, it's not legal. Which begs to ask about the apartment itself.

Even an open, unfinished basement probably doesn't provide the necessary combustion air for the burner.

What brand and model burner?
There's always a way to do it right. Especially when lives might depend on it.

Give some more info. Post some pics. There are options. The louvered door is not one of them.

mattyc

@Jamie Hall the apartment is a decent size. Aprox. 400sqft It currently has baseboard on just about every possible wall which I know from experience is way too much...when the heat turns on it only has to run for about 2 minutes untill the thermostat is satisfied and then the apartment overheats. If it were me I’d re-do the entire boiler room to get the temperature down to the baseboards low enough to get near continuous circulation with a condensing boiler but again since I rent, all I can do is shut some of the vents off for now....I read once that a rule of thumb was to subtract a certain percentage for the extra heat gain from the boiler but for the life of me I can’t remember

mattyc

@HVACNUT it’s a thermodynamic s series Steel firebox boiler with a Beckett Burner firing a .75• nozzle at 140psi. Again, I only rent so I can’t make any real changes to the system. It is what it is unfortunately lol. I’m just concerned about the Heat put off from the boiler effecting my heatloss that I am currently doing to try and figure out how much baseboard I can remove from the system.

STEVEusaPA

400 sq feet and 100K boiler. Too big even for the North Pole.
I don't quite know what you're asking @mattyc. Is the place too hot? Do you also use it for domestic hot water? Don't see how a heat loss calculation helps you solve any issues, unless it was being replaced with a very small gas-fired option (combi, mod-con).
Don't think there's a whole lot you can do. If it's too hot, you could try closing the dampers on the baseboards (if they still work), or wrapping the element with aluminum foil.
If you have an aquastat (or boiler piping) that prevents condensation in the boiler, you could try lowering the aquastat.
---
I have a customer with a 2 unit building and 2 Thermodynamic boilers-S100, and S85, both ridiculously oversized. Sad, and wasteful.

mattyc

@STEVEusaPA the boiler also heats the 1st floor and 2nd floor of the house as well as the basement apartment. And it provides hot water through a tankless coil....my question is, in doing a heatloss calc on just the basement zone to figure the amount of baseboard that is really needed to heat the room (it’s putting out 180 degree water), I need to figure for the extra heat that is put off from the boiler room itself. The boiler room is in a room right off the living room..that extra heat from that room effects the amount of baseboard needed. I just forget how to figure for that extra heat being put off from the boiler.

STEVEusaPA

Ahhh...much clearer now.
Still don't understand what you are going to do with that calculation, once you figure it out.
Hopefully this is zoned, and you have you're own thermostat.
Like I said, if you're getting overheating in your apartment, close baffles or put some aluminum foil over the elements.
Not much more you can do in your situation.
Also you could insulate all the near boiler piping so less heat radiates off of it into your apartment, but you're kinda getting that heat for free when other apartments are calling for heat.
Edit: I wonder how the tankless is doing with 2 apartments.

HVACNUT

Do what they do in apartment houses. Open the window.
Kill two birds.

GroundUp

Heat loss troubles aside, why are you even considering altering the heating system in a house that you don't own? This is a great way to be sued by the owner- don't touch it. If the lower level is not heated sufficiently, talk to the landlord and get it fixed on their dime- remove yourself from the equation for your own safety.

EBEBRATT-Ed

@mattyc

If you want a cheap way out cover the fins in the baseboard by wrapping the fins in aluminum foil to cut down the heat output.

Trial and error cover some and wait to see if you need to cover more

hot_rod

Most baseboards have adjustable dampers you could close and limit heat out put, it may be easier than covering the fin. Sounds like heat from above and the mechanical room itself may be over-shooting your thermostat settings?

mattyc

@hot_rod yes the boiler room itself and the fact that I have probably 5x the amount of baseboard installed then what I probably need are overshooting the thermostat everytime..not to mention the fact that this zone only needs to run for 2 minutes untill the thermostat is satisfied( I’d like to get a longer runtime)...I was planning on just closing the dampers on the baseboards for now. My question is, if this were a normal heating zone (imagine there wasn’t this massively hot boiler room in the living room closet) and my heatloss tells me that I need “x” amount of baseboard At 180• to heat the zone...is there a formula or a “rule of thumb” to determine weather or not I can subtract some more baseboard due to the fact that the boiler room off the living is putting off all this heat into the zone...I hope I’m explaining this correctly lol....maybe the answer to my question was already answered in one of the coffee with calleffi webinars and I’m just forgetting. I’m not sure. Thanks for the help from everyone’s who’s commented

Jamie Hall

I don't think there really is a usable rule of thumb, since the amount of heat dumped from the boiler will vary so widely. A very old boiler with miserable insulation, for instance, might have a solid 20% of its rated input being dumped in jacket losses. A modern boiler with good insulation could easily be as little as 5% or even less. In the case of your miserable setup -- anywhere from 5,000 BTUh to 20,000 BTUh easily, which is a huge fraction of your heat loss.

hot_rod

Got an infrared camera, that would give young good visual and some numbers to better pin down what then boiler and all the piping iso transferring too the room.

From what you describe I suspect most of the heating season, the standby and piping loss is covering you heats loss without even needing the fin tube

Search around this site for various infrared pics of boilers, radiators, pipe, slab, etc.

Also use the IR to see where the heatloss is in you space, windows, doors, weatherstrip, etc.

The small I-phone IR cameras have become affordable.