Smallest Mod-Con w/Integral DHW?

Steamhead

We just calced a very small house, owner says scorched-air is making him sick and wants to go hydronic. Heat loss just under 28,000 BTU/hr at design, no basement, oversized furnasty in kitchen along with 30-gallon gas water heater. It's as perfect a place for a wall-hung mod-con with integral DHW as I've seen.



Before we start plowing thru catalogs and Web sites, anyone know of such a small unit? Thanks in advance.

EricAune

Might be too large but...

Check out the NTI Trinity Ti150 combo unit



http://www.nythermal.com/trinity_ti

Robert O'Brien

Frank

The TT Excellence is a 110 boiler w/ 14 gallon indirect in the 399  enclosure.I did one a few months ago,worked out great! Or maybe something like this? 

http://www.slantfin.com/product-combicat.html

Steamhead

Interesting

the Slant/Fin people weren't kidding when they said they had a lot of new stuff coming out.



So far, the "how low can you go" champs don't have integral DHW, but that S/F heat exchanger or the TT Mini-Smart look like they would be a good fit. The lowest inputs I've found so far are the TT Prestige Solo 60, which goes down to 16,000 BTU/hr input, and the Munchkin and Contender 50 which go down to 18,000.



Anything else out there that can go lower?

kcopp

a line that I really like

is the Emabassy line gives you a good, better best set up in the BMS, Axia, and the Onex....  www.embassyind.com 

The onex is a mod /con and you can dial it down to 25K ... and yes it does heat AND DHW in one unit!

Or you can look at this same one that Smith offers... the GC160.



kpc

Robert O'Brien

I

I can't vouch for any others but the Prestige is first rate.

TonyS

Prestige is an excellent

boiler.  It is my favorite modcon. But stay away from the mini smart tank, I have one in my shop and it isn't even good for that. Its takes way to long from the time you start to using water until you reach a steady state. HOT.......WARM........COLD.........WARM    HOT. The Excellence works much better because it has storage and gives the unit time to get up to temp. Also it is a tank in tank design not just a coil in a tube. Unfortunatly it is only available in the 110.  The 60 would be the ideal unit and maybe a tankless for domestic.

hot_rod

Baxi

I installed a Laars, a rebaged Baxi 330 I think with a flat plate inside for DHW. It works great with a one faucet draw. A flow switch switches the boiler from the heating load to the plate HX.



It will take 100,000 BTU boiler, or more to generate instant DHW through a plate HX. If they want to run multiple loads, be careful with those instant DHW via plate HX setups. You can run the numbers if you know the incoming water temperature and the gpm they want.



hr

SpeyFitter

Lochinvar Knight WB50

How about a Lochinvar Knight WB50 - modulates from 10,000 to 50,000 BTUH, with a 30 or 40 gallon Lochinvar Squire Indirect? Yes, not an Integral plated heat exchanger model like you're thinking but considering the low heat loss I think this is probably a better option than short cycling a bigger boiler for the heating load just to have the option to do Integral Domestic hot water with a plated heat exchanger.