1 season of oversized boiler solution

BenWoj

I moved into an old 2700 sqr ft house which has a 140000 btu hot water boiler. Over the past summer I've been remodeling the house and switching over from baseboard to underfloor heating. Currently all of the baseboard is removed, and the underfloor tubes are in place, but empty. Next spring we hoped to remove the boiler and replace it with a geo system, but until then I'm not sure what to do with my heating.



Currently I've been heating my first floor only with small radiant space heaters. Although effective for the most part, and cheaper than the $500 a month lp bill we had last winter, its not very safe and I wanted to get my boiler up and running.





Since I'm only truly heating the downstairs (upstairs unfinished) I'm going to have a very short cycle on my boiler since it would really only be heating one zone. I've purchased a taco mixing block which will help a little, but I can't image much being that oversized.



Are there any solutions to this problem? Do I suffer with the short cycle the remainder of winter, do I do a quick insulation job on second floor and open up a second or third zone?



Thanks

Steamfitter66

I assume its an older cast iron boiler

I would not worry to much about short cycling or condensing and just hook up what you need directly to the boiler and turn your aquastat down to 140 and see what it does.

Older cast iron is pretty forgiving.

Have the boiler serviced to ensure safety.

SWEI

Heating One Zone

Is that one zone of in-floor radiant tubing?  Not a good idea with a cast iron boiler of that size (unless you add a buffer tank and mixing valve.)

Steamfitter66

Its staple up, at least thats what I got from the OP

Which is why i recommend that, since its temporary heat, he just hook it up direct.

BenWoj

Yes, infloor

The first floor is infloor radiant heating. I purchased a taco mixing block to allow a lower temp into the floor instead of direct from the boiler. Also allows boiler protection so it doesn't condensate.



My biggest worry is how much $$ am I going to burn away with such a small space to heat. And is there anything I should consider doing to make it somewhat efficient? This is a relatively new boiler installed two years ago.

Steamfitter66

Building envelope will have the biggest impact on energy used.

I missed the infloor, use the mix block and set the aquastat to 150 min.

If its a sectional cast iron boiler you may be able to plug some orifices, but this depends on the design and should only be done by an experienced boiler tech.

SWEI

What kind of in-floor?

How are you attaching the tubing -- from underneath, or above (before laying down flooring)?  Did you use plates?

Gordy

My concern

Is the staple up coupled to geo. I hope some serious heat load calculations were done. Don't expect to get swt above 115 120 with geo.

BenWoj

Sorry for the confusion

I should clarify a bit more.  Sorry i've been confusing everyone, but I was trying to type the best I could and as quickly as I could on my phone.

The original owner had the boiler hooked up to baseboards, but he also had the first floor as infloor heating (cement) but direct from the boiler.  We are currently in the process of correcting and upgrading everything (adding manifolds, removing baseboard installing radiant floor (yes with plates), ect...) 

I currently only live in the bottum half of the house.  The second floor is half done, so I dont plan on heating it.  I've been running off space heaters the last week or so (michigan) so I wont freeze my butt off, but im finaly getting around to hooking up my boiler to the manifolds.  Since im only heating the first floor this winter and knowing my boiler is extremely oversized for this, I wasn't sure if there was something I could do that would prevent the constant recycling.  Heating with space heaters is actually cheaper then my heating bill last year using LP, but its not keeping the rooms warm on the cold nights.

Should I bight the bullet and just run it for the few months I have and spend the extra $$ ($500 a month) or is there a cheap fix until I get a new geo system?



Thanks again for the help and sorry for the confusion.

SWEI

Buffer on the cheap

If you happen to have and electric water heater around (old OK, leaking not OK) you could pipe it in to reduce the short-cycling.