is it worth the effort

Larry Savino

I was at a new customers home, its about 13,000 square feet. They have 2 210,000 btus boiler about 8 years old spark ignition with stack dampers with about 6 or 7 zone of baseboard heat on them each and a dhw storage tank. he just recently purchased the home

I was there to give a price on connect some already roughed in radiant heat witch I am passing on as it seam who ever roughed it in just took a couple of 1000 foot rolls of pex and set the whole roll out to the floors, 4 loops and they are each 900 feet each.( we have no idea of how many square foor of floor area its actually doing as he purchased the home this way.

Anyways when we install this much boiler we always install it as a primary secondary loop with the boilers being controlled by a tec mar indoor out door reset with a lead lag set up. What the guys has now if only one zone is calling it will fire the boiler its attached to and if another zone on the other boiler is calling it will also bring on that boiler so in effect he could only need to raise the temperature 2 degrees in 2 small zones and have to fire up 420,000 btus on a 50 degree day

what type of saving could I suggest this fellow might get if i was to set it up as a lead lag with a tecmar indoor outdoor reset with the primary secondary piping with the boiler injecting the hot water into the primary loop ?

He has not moved in yet and the stats are all set at 45 degrees,the house is completely sealed up with minor renovations going on and his last gas bill was $1,000.00 So yes he is ready for some recommendations on how to improve the systems economy

Constantin

I would proceed with caution...

I would worry that the construction quality of the home will mirror the quality of the tubing install. Given the thickness of the wallet of your client, now would be a good time to hire a IR camera and blower door outfit and take stock of the house's condition.

As for the tubing, you'd have to knock out some holes to get at it or use hot rods 4-way mixer... either way a 900' run would require a rather ridiculous pump to move any kind of flow... So, the question is, does the client want holes knocked in the floor to make it right?

Only once the envelope and so on has been addressed would I move on to fixing the boiler room. Unless you have the external data, you don't know what you're in for.

S Ebels

I agree

You have been asked for recommendations. Make sure that whatever course of action you advise is based on fact and not a seat of the pants gut feeling. Not to say that your intuition won't be right but you better have the "ammo" to back up what you tell the owner to do. Starting with a blower door test and a few shots with an IR camera on a cold day will do wonders for selling your proposal to the customer if they reveal a problem.

I also agree that the system presently installed is stupid controlwise. Sounds like a job that's crying out for a modulating/condensing boiler to handle the mild weather with maybe one of the present two retained for conditions requiring higher temps. (>160*) Your primary/secondary scenario would certainly be an advantage just by itself but baseloading with a condensing unit would probably pay off well for the HO.