Weil-McLain Ultra and Hydro-Air

Dave_61

We're thinking of replacing our current boiler with a Weil-McLain Ultra, but I was told that you'd want to run the hydro-air coils with 180 degree water, as otherwise you'd feel cool air blowing if you use lower temp water.
Is this true? How low of a water temp can you run the hydro-air coils comfortably?
Is W-M the best boiler for this setup as far as efficiency and comfort?

Kal Row

the ULTRA is great for any load....

Thats why the competition is feverously bringing a similar product to market – even the vie$$man and the munchkin fall short of the ULTRA’s versatility

see bottom of http://forums.invision.net/Thread.cfm?CFApp=2&Thread_ID=22826&mc=40 thread


as for fin coil discharge temp - depends on fan speed and distance from registers to people - dont want to strike people with more and 110 degree air - you need a discharge plenum sensor driving a mixing valve or a vari circulator

on commercial applications i use three, "return air", "discharge air", and on the coil itself for min temp freeze protection - unfortunately my favorite control people "tekmar" dont make anything like that, need to go to the heatTimer corp for their latest multi mode digi-span control

Floyd_7

Don, It will work great....

A few things that will help.....
Make sure you size the ductwork for low resistance and good air flow. Get a blower with a EMC motor so you can slow it way down. Don't be afraid to run it all the time in very cold weather. Size the piping for good water flow and choose you pump accordingly.
Then get WM's Gascom software to program the boiler for use with an air handler. They have a setup just for use with air coils. I'll attach a pic of the parameters from the software.

Have fun!!

Floyd

larry

We are replacing some FHA furnaces with a hydro-air setup over the coming weeks. I believe it's possible to have a sucessful hydro-air setup, and use supply temperatures way lower than 180F. After we have the units installed, I'll be taking some measurements and quantify exactly what air temps are derived from a particular water supply temps and delta T.

As others have mentioned, the key is being able to modulate both the pump and the blower to your best advantage. If you don't do this, it makes sense that higher supply temps will be needed. Finding the right air handler and controls that can do this are key. I've gotten the sense that doing this sort of thing is commonplace in large commercial installations, but the equipment to do this is scarce in the residential market. Blowers with ECM motors are capable of all sorts of things, but I don't know of a single hydro-air handler which implements an ECM motor and does anything intelligent with it. The only dedicated hydro-air handler I was able to find with an ECM motor (as an option) was made by Nutech. From what I could tell, Nutech doesn't do any special temperature-based speed control with the unit. Other ECM based AHers are sold by all the furnace players. By adding hot water coils, these can become hydro-air handlers. Again, I'm not aware of any dynamic temperature based speed control being done on these units on the heating side. Some do implement speed control on the cooling side to optimize dehumidification.

jerry scharf_2

What do you like better

Kal,

Those are strong words. What is it that you like so much better than the many other modulating/condensing boilers on the market? I'm always interested in what other people value in their favorite products.

jerry

Uni R

Bingo!

You know... it's excellent how you pointed that out so that some of the many excellent thinkers here would rethink their stereotypes about air handlers needing 180, just as they have already stopped believing the HWBB can't even be considered as heating devices when their input is under 140.