Tankless Water Heater and Air Handler

[swarwick]

Hi,

Mindful of the pros and cons expressed on this site, I plan to install a tankless water heater in my home. Like my present water heater, my gas furnace is also on its last legs. I am thinking of installing an air handler instead of a new furnace, and having the air handler warm the air with hot water from my tankless. I am told it is best to install a commercial tankless to do this job (which I am fine with). Apart from that, does anyone have any thoughts/concerns about making this transition? As you can probably tell, I'm an HVAC neophyte.

Thanks kindly for all responses.

[Johnny Law]

This sounds like buying a 4cylinder car for economy and putting a C5 jet engine in it.

[tuckerin]

Would rather see a Munchkin boiler with indirect water heater and hydronic fan coil, all components are long service life and designed for the job at hand. Would outlast by a factor of 3

[hvacconsultant]

Would rather see a Munchkin boiler with indirect water heater and hydronic fan coil, all components are long service life and designed for the job at hand. Would outlast by a factor of 3

The two hot water fan coil units with DX cooling I've seen are rather expensive. I recently had a project in a hospital where I needed to spec exactly that, and I only found AAON and First Company that made them. Do you know of any others?

[tuckerin]

I have used the First Co. units on the residential jobs, didn't find them expensive, about half the cost of a gas high end furnace. Used airtherm units in church jobs and hospital additions. The good systems cost a bit more and should outlast the mortgage IMHO. I check out my prospective customers and when I hear "how much" three times in the first ten mins. I leave them to the bottom feeders.

[hvacconsultant]

Thanks for the info. I'll call my Carrier rep since they handle First Co and see what the price is. I believe the contractor just priced out the Aaon unit and it was really high. I didn't actually see the bid, but that client doesn't usually complain about price so it must have been bad.

Looks like those Airtherm units are chilled water, not DX. The problem with this specific job is that they need cooling almost year round and chilled water isn't available from November through March.

I'll stop hijacking this thread and investigate the First Co units further.

[Accurate]

Hi,

Mindful of the pros and cons expressed on this site, I plan to install a tankless water heater in my home. Like my present water heater, my gas furnace is also on its last legs. I am thinking of installing an air handler instead of a new furnace, and having the air handler warm the air with hot water from my tankless. I am told it is best to install a commercial tankless to do this job (which I am fine with). Apart from that, does anyone have any thoughts/concerns about making this transition? As you can probably tell, I'm an HVAC neophyte.

Thanks kindly for all responses.

My understanding of tankless is that while they may output 180 degree water they will not give the volume of water at that temp to satisfy the air handlers.

[dan sw fl]

I am thinking of installing an air handler instead of a new furnace, and having the air handler warm the air with hot water from my tankless.

Apart from that, does anyone have any thoughts/concerns about making this transition?

Tankless is not a realistic, economical option.
You will likely need a new electric panel to handle 50 - 100 Amps.

Heat pump with back-up electric strips is the normal equipment used in many parts of the U.S.

Dual fuel with gas furnace may also be an option.

Look up your local utility (gas & electric) rates.

[swarwick]

Thanks to everyone for taking time to respond.

I think I could have been clearer in my post. My tankless water heater will be gas (I live in southern Canada) and if I go with the air handler option, my contractor has advised me to use a commerical tankless, so that there is sufficient volume of water (at, I believe, 180 degrees) to run the furnace.

I appreciate that the tankless heater may or may not be more economical than a tanked version in the long run, but I have decided to go that route. My only question is whether I should tie a new furnace into my tankless. I just don't know enough about furnaces (other than the standard gas models) to decide what to do.

Thanks again for everyone's time.

[dan sw fl]

My tankless water heater will be gas
(I live in southern Canada) and if I go with the air handler option, my contractor has advised me to use a commerical tankless, so that there is sufficient volume of water (at, I believe, 180 degrees) to run the furnace.

I just don't know enough about furnaces (other than the standard gas models) to decide what to do.

IF it is a True-Tankless how does one have ANY volume of water,
let alone a sufficient volume.

The semantics of (terms used in) this thread seem to defy logic.

I believe that a Gas fired True-Tankless water heater
would more commonly be known as Boiler