Rinnia e 110 and a comfort air wet coil

Snowmelt

Ok guys tell me me what you think. Have a customer that wants a combo boiler. He has forced hot air right now. So he suggested a wet coil in the air handler. He does live on the 6th floor in Hoboken. Updating gas line isn't an option. The customer has an existing furnace 100,000 btu in.
Customer and I agreed on a e-110 combi and a comfort air wet coil. Units will be within 5 feet from each other. First will it work, the boiler needs to be at high 175 degree water to make the heating btu to satisfy the load on the house. That's the reason I'm going with the boiler instead of a water heater. The reason for the e-110 instead of the 75 is for more gpm per gallon on domestic. Is this reasonable request? Secound I was looking at the diagrams for wet coil, seemed like if there wasn't a big pressure drop you don't need primary secoundary looping.
Any info is appreciated.

lchmb

The Rinnai comes with the low loss header. Makes for a very simple hook up. Connect to the bottom of the boiler, connect into the header..done.. As far as more gpm on domestic, how big a shower does he have? If the add up requires it, rather simple. High temps on this boiler wont give you maximum efficiency but it will work and very quietly...though I would think you could still run at lower temps in the shoulder season. Just change your heating curve (and what activates the coil fan?).

Snowmelt

I am going to assume a air handler fan relay, which i have two sitting on a shelf that wasn't used for a job. the customer is an older couple with no kids and a regular shower head. The reason I don't think i need the L.L.H. is because I am in the same room as the air handler and looking at the diagram. I was looking at the space. in reality the two machines are going to be right next to each other so less then a five foot between them. If I get lucky It will just be 1 10 foot piece of copper. 1 inch diameter.

wcs5050

love the e-110-cn. it performs really well. make sure to mention/sell 2 year maintenance. flat-plate for DHW susceptible to sediment and scale build up. wash with vinegar, as per manual instructions.
nice unit. low loss header included as mentioned, but connections can leak, and make a mess if not properly made.
use a strap on close-on-rise Honeywell on supply piping to air handler. set it under lower than needed so it comes on early, then purges after heat call.

njtommy

Why wouldn't you design it for 140 supply temp for better efficiency?

wcs5050

boiler has an outdoor reset. better to have fan switch low for those lower supply temp days.

Snowmelt

Need 80,000 btu to heat the structure. With 140 degrees I can only get 40,000 btu.

Snowmelt

I'm looking at some of the diagrams, it looks like I can save some space if I don't need the header. Looks like I can just add issolation valves on the unit for flushing of the unit.

njtommy

Got ya. Are you going to vary the fan speed as well?

Snowmelt

No just one set feed span.