Tankless Boiler/Water Heaters

GIGIRC

Hi,

I have had a contractor recommend to have unico and Navien 150 On Demand Boiler & Hot Water system installed to service my 3 story townhouse. He advised me to this because the unico could then be used for both and the heat coming out of the vents isn’t a dry heat due to the hydronic heating coil. This would mean no more baseboard or radiators.

I know there are some experts amongst here, wondering your thoughts on this Vs split system + Navien 150 On Demand Boiler & Hot Water.

Do people like the Navien or prefer other manufacturers?

Thanks for your thoughts in advance.

John Mills_5

Shows he doesn't know much about humidity

Homes dry out because outside air infiltrates, is heated by ANY source and the RELATIVE humidity is greatly reduced. The heating equipment doesn't dry the air. There isn't a condensate pan under a radiator, gas furnace heat exchanger, Unico hot water coil. The amount of moisture in your house stays the same but since warm air can hold so much more moisture, the RH% goes way down when this cold air that leaked in is warmed. Want to keep the humidity up? The solution isn't his Unico, it is tightening the house.

As for whether to go Unico and what boiler, I'll let others more into high end boilers handle that.

Rich_49

Why does he want 150K combi ? How many square feet is this townhome , 7,500 sf ? Maybe he is oversizing your Unicco also . Maybe you need something not tankless unless space is an issue that YOU are concerned with more than actual efficiency .
Try this instead , see what he says about it

http://www.htproducts.com/phoenixldwaterheater.html

http://www.htproducts.com/phoenixwaterheater.html

There's your combi , with much less maintenance required . The difference is that these are not oversized and you'll actually get enough hot water for your 2 1/2 bath townhome .
By the way , where are you located ? Just a bit of information , Navien has had more than 13,000 units recalled for some very dangerous problems . The following is just the most recent . Is this what you want in your house ? How many were seriously injured before they recalled them ?

http://www.consumerreports.org/cro/news/2011/12/recall-navien-tankless-water-heaters-for-carbon-monoxide-risks/index.htm

http://www.cpsc.gov/en/Recalls/2012/Navien-Recalls-Tankless-Water-Heaters-Due-to-Risk-of-Carbon-Monoxide-Poisoning/

GIGIRC

Thanks Rich.

Some follow up...

3 floors, each one is 600 sq ft but we are only installing HVAC for top 2.

Space is def a consideration. We are going to upgrade from our old boiler and water tank now and the question is to what. We do like the current form (baseboard/radiator) of heating and if we could have a similar heat but via vents that would be great as we could remove the old baseboards we have now. If not, then we would look to update our baseboards.

We currently have window units for air conditioning.

Live in brooklyn, NY.

Would love to hear thoughts on right sizing for this.

Rich_49

When was it built and do you have a good idea about insulation values , window type ? You are not gonna get the same comfort from forced air unless it is done impeccably . The guy you are talking with does not sound like that guy . As a matter of course , there are many who think they are that guy but very few actually are . My first guess is that you should probably require 20 BTU sq ft or less , to be more precise your heat load probably will not exceed 36,000 . This is dependent on whether you are an end unit , middle unit and based on the heat loss calc . By the way , did your contact perform one ? If not , get rid of him . What size Unicco is he specifying , if I may ask ? Has he mentioned outdoor reset being utilized for the coil at the air handler ?
Feel free to contact me if you wish .

GIGIRC

Rich - would love a chat. What is the best way to reach you?

Rich_49

Phone number below every one of my posts .