Replies

1. 
   Clewless1 | Aug 02, 2008 07:51am | #1

   Need some clarification for starters. Confused me (could be me, here).

   Furnace usually means an air system, ductwork, etc. but you say furnace and hydronic in the same sentence. Then you said when you did your 2nd floor addition, you couldn't add ductwork ... so what do you have??

   You can use a hot water boiler (i.e. water heater) and put a hot water coil in your ductwork ... instead of a direct fired air furnace. You can combine domestic hot water heater and a hydronic space heat system (e.g. serving a hot water coil in ductwork or baseboard hydronic heat) into one water heater (i.e. boiler). There are a number of manufacturers of combined water heaters/boilers. I used one for a radiant floor heating system ... has a heat exchanger in the water heater for the radiant floor (or in your case baseboard or coil in your air handling unit ('furnace'). Can't/shouldn't use potable water in your heating system, but you can use the same water heater.

   Need some clarification ... hope I didn't fly right over your head ... I can clarify if you need. 

    

1. 
   jroy | Aug 02, 2008 06:57pm | #2

   I have a seperate heating system for the 2nd floor (which is located in the attic).  Hot water from the oil fired water heater in the basement, is piped into the attic to a hydronic-air hybrid system to provide heat for the 2nd floor.  Unfortunately when someone wants to shower in the morning the water is tepid after being used all night as a heat source.

   With my furnace getting on in years I thought that it may be wise to tie a new boiler in the basement, one with an indirect water heater, to the 2nd floor unit to provide one system.....and to provide hot water as well.  From what I have read hot water is more efficient at producing heat than hot air.  My current source of heat is a oil fired hot air furnace.  Ductwork is already in place for both first and 2nd floors, which I hope can be used if I convert (the first floor to a hydronic-air system).

   Hope this clarifies my poorly phrased opening remarks from yesterday, and thank you for responding.

    

   jr

    

1. 
   Clewless1 | Aug 09, 2008 05:17pm | #5

   I'm surprised that your water is luke warm after a night of cold weather. The boiler/water heater should always maintain its temp ... unless it is way undersized ... which would be evidenced by it continuously firing (running) in the hour just before you take your shower. If it is not firing ... then the temp is maybe set too low. Do I assume you have a thermostat operating a pump or valve on that 2nd floor system?

   Installing a hydronic coil in your existing lower furnace would be a good consideration ... One boiler ... two coils. You could combine domestic hot water and the boiler into one (I have a radiant floor system that shares a domestic water heater).

   Your concept is sound ... and rather than having the expense of a air only furnace replacement and maybe another water heater replacement in the future, you are already poised to combine them. Do more research on the specifics of your options to ensure every dollar you spend is working for you in the best way.

2. 
   bobguindon | Aug 02, 2008 11:17pm | #3

   This will also free up a flue opening in the chimney to put in a small wood stove to supplement the heat

   Not to nit-pick here, but I hope you mean 'flue' and not 'flue opening'.  I don't know of any jursidiction that will allow sharing a flue for a solid fuel fired appliance with that of a liquid or gas fuel, unless the appliance is listed for the purpose.

   This model is one of only a few that I've found with that listing:  http://www.mainewoodfurnaces.com/CC500.shtml

   Thanks to it's revolutionary one piece design, the Benjamin CC500 is classified as a "single appliance". This enables it to be connected to a single solid fuel chimney flue, further reducing your installation costs. Maine code allows for this use, and insurance companies are agreeable to it as well.

   The above excerpt is from a Maine dealer of boilers and furnaces, hence the reference to Maine code.

   If I have mis-interpreted your post and you do, in fact, already have 2 flues, please accept my apologies and return to your original program, which is already in progress...

   Bob

   
   

   ---

   Edited 8/2/2008 4:18 pm ET by bobguindon

1. 
   jroy | Aug 03, 2008 11:15pm | #4

   My faux paus as far as venting a wood stove into a flue used by the oil fired heating system....upon futher study I realized that this isnt an option!  But I thank you for voicing your expertise and putting in your thoughts...

   So, strike the idea of a wood stove using the same flue, but Im still intrigued with the idea of a hydronic-air system with an intergrated water heater...any thoughts that you guys can share would be greatly appreciated by this reader.

    

   jr 

3. 
   DDay | Aug 10, 2008 02:57am | #6

   Just put in a Buderus 115 oil fired boiler with a megastor indirect. The indirect will give you endless hot water and is also much more efficient than going with a tankless. The megastors are so insulated that over the summer the boiler rarely comes on due to a drop in the tank water temp. I think it loses a degree an hour. The boiler is also one of the most efficient you can get, nice clean install, 3" of insulation around the entire boiler, including the bottom, etc.

   For the hydro air set up, use the basic logomatic. The higher end logomatic control is not worth the money for a hydro set up, you'll get features on that, that you'll never use.

   Also, I am in MA too and have nstar for electricity, they offer a $500 rebate on efficient boilers and $300 for the indirect. Whether you have them or not, your electric company probably offers the same. I believe you can also write the upgrade off on your taxes too since it is energy efficient but check on that. You need to sign up for the rebate before the new one is installed so they can see the old one and see that you are upgrading the efficiency.