Help Chosing new Gas HVAC system- Hydronic/Air - Northeast 2 story home/gar 2600sf

jav

Sorry its long - existing system almost 30 years old. Been good but I have some regrets.

Existing System - Gas boiler 85% eff. power vent -(combi unit with DWH tank in base) Hydro air with 3 handlers, 2 of which also incorporate R22 coils. 1 handler is in attic- Glycol in use.

Likes- Reliable. Original DHW tank intact and has never failed or even needed chemical cleaning. Heat & AC w/good humidity control year round. Easy to have multiple zone heat.
Dislikes- Running anti freeze & routine flush/replace. Seepage at fittings. Complex (5 pumps ( primary, dhw, +3 zones)) balancing hydronic flow challenging due to low volume high flow HE boiler- noise, flow, balancing w/ calling zones etc. Not very efficient. Pipe freeze worrys antifreeze concentration. Attic ducting not great summer or winter.

New system- Option 1 - stay hydronic- hydro-air design (perhaps Lochnivar combi boiler) and new handlers and a-coils etc. Anti-freeze / freeze concerns remain. Newer modulating pumps and perhaps low loss header system design could address noise flow balance issues? Complexity still high but least invasive- most similar to existing. Can still have 3 (or more) heating zones easily.

Option 2- Abandon Hydronic. Go with 2 small HE furnaces. Have recently installed a few systems (goodman) and have been impressed. Pro's - much simpler and easy to configure. Can use existing ducts- which aren't great but must stay due to placement in vaulted ceilings. Seems more efficient than hydronic? No more anti-freeze / freeze worry!!! Cons. Running gas to attic (not a huge deal). Loss of 1 heating zone (garage- not ideal but not a deal breaker). Back to free standing DWH w/4-8 year life or on demand (not a huge fan at 199kBTUH)

If it were your house- how woould you go and why?

SuperTech

I'd do neither option.  I'd want radiant floor heating with the ductwork for A/C.

I guess if I had to pick one of the two listed I would stay with the hydro air. I would probably stick with a boiler in the 85% efficiency range for its longer lifespan. I would probably install heat pumps instead of a cooling only system. 

offdutytech

In a similar situation. We are looking at doing an addition and plan on infloor heat. I'm looking at retro fitting other parts of the first floor house with in floor as well. I've contemplated replacing the 80% gas furnace with a hydronic air handler, ditching my hot water tank and doing a mod con or comi. Gives me a chance to fix a few things with ductwork, but I'm in the trade so for me cost is just for materials. Personally I like hydronic heat better than gas forced air. In addition i'm not hiring a contractor, so it's somewhat cost effective for me. 

As far as Goodman, goes... some contractors solely install it. I would say there are some better options out there. The fit and finish to of the equipment is cheaper quality IMO vs other brands. The company I work for installs Luxaire which is a JCI product. The thing I like about that is there are parts used on other JCI brands that are universal across the brands and easy to get at multiple supply houses near me. I can only get Goodman OEM parts online or at one particular supply house. May not be a huge deal where you are at. Just boils down to ease of service for me. 

EBEBRATT-Ed

Hydronic wins for comfort most all the time. The average duct installer can't get it right. If warm ar is done right it can be a good system. But it suffers in building with high ceilings and air stratification.

jav

thanks for the responses. I'm actually thinking I might go Hybrid since my biggest problem with my current system is the attic unit. 1 becasue it forces me to run antifreeze but also because the ducts are not in conditioned space. Also, my second floor is all valted ceilings which on top of stratificantion, cause the ducts to to heat or cold soak quite quickly. So when that zone calls, the first 5 minutes are spent normalizing duct temps and as a result, in the summer- the ac blows hot and worse- in the winter due to the lower hydroair delta T, the ducts actually blow ice cold which noticeably causes an inittal temperature drop.

Because of this, I think a gas furnace in the attic would help since, the antifreeze would go away and, the heat exchanger being a greater Delta T -may minimize the time to normalize ducts and heating space? I could then keep a hydronic system without antifreze for the other non attic zones. Thoughts?