oversized

Paul S_3

Hey everyone...just got back from job, baseboard series loop hot water system heat loss its 48,000btus, customer had someone install a cast iron atmospheric 130,000btu boiler grossly oversized and piped improperly....I went there for no heat and the loop was air bound....I got the job to pipe it properly...pumping away....but I want to address the short cycling....would primary/secondary help? Any recommendations? Thanks Paul s

hot_rod

seems to be

a lot of this going on the past few weeks.



Sounds like the boiler is twice the size you need. Probably not going to be a piping fix for this. A buffer tank can help somewhat, not a perfect fix, but price it against a boiler replacement and offer it to the customer.



Finding a new, comfortable home for that boiler and installing the correct one would be the best "win"

Rich_49

Rod

is 100% correct . If help is needed sizing the buffer tank , we can help . And yes , there is a proper procedure for that as well . I generally use Caleffi Bufer tanks , they come in 25 , 50 , 80 ,120 gallon sizes . If this is a 1 zone house taking into consideration an 85% boiler and baseboard heat and a minimum 10 minute cycle you would require a 62.5 gallon tank . Since this may be your option I would offer the homeowner Outdoor reset also if the installed baseboard lengths are conducive . .

Paul S_3

baseboard

Its a 85% boiler....and there is one 3/4 '' inch zone...which has 52 feet of active element....Paul S

SWEI

Are they freezing?

52 feet of what?  High-output commercial BB?



By the time I add a buffer tank, a second pump, mixing valve, and controls a properly sized mod/con starts to look pretty good.

Paul S_3

3/4

Slant fin fine line 30 .....no heat works fine....i quoted him last year to replace boiler...he went with another company, then he called me because the other company stopped coming back, customer says that he has to purge the loop once a month of air. So i gave price to pipe boiler properly, and want to address short cycling Paul S

SWEI

With a 48k heat loss?

or did I miss something?

Paul S_3

heat loss

Heat loss of home came out to 48,000 btu, there 52 feet of fine line 30 in home, which equals to about 31,000 btus, previous installer installed a 130,000 btu boiler, I figured that his constant air problem was coming from a improperly piped boiler, so I quoted to address air issue. And Im going to give a proposal to address short cycling. I told the customer last year about the baseboard issue when i gave quote to replace boiler, i wanted to add 2 zones, 1st and 2nd floor, yes 1st and 2nd floor are ONE series loop!....thats probaly why i lost job...it heats the home for some reason, on cold days the back rooms get cold....I live in NYC this is what I deal with on a daily basis. Thanks Paul S

hot_rod

keep in mind

baseboard in a series loop will not give you the same output at the end as the begining, you need to consider the temperature drop in each foot of BB.



Without all the data the BB simulator shows about 100 feet of BB to get that load. although 65-70 feet is usually the max for one zone.



52 feet is around 26K to load 6 gpm 10°∆T Probably covers the load on all but design conditions, maybe the room temperature slips a bit when it is cold, cold?



You can run all these what ifs in the HDS software, change pumps, flow rate bb, etc

Steamfitter66

aquastat must be turned all the way up?

You could be getting over 40k at 215* and 6 gpm.

I would use a 50ga EWH and pipe boiler supply to top, system supply from drain with pump installed bellow the top of the water heater. Install a air vent in the other top tap and you have solved both problems. Make sure you have enough pump. outdoor reset would help with comfort and energy.