Replace Hydro with Forced Air?

[camshaft]

My current home is 1600 sq ft, 2 story double brick construction (circa 1939)located in Southern Ontario. Next year I am planning a 1100 sq ft 2 story addition. Currently have a NG boiler / cast iron rads. Boiler is 26 years old. No A/C in the house.

I am considering changing to a gas forced air system and removing the old equipment and rads. I do want A/C included when the addition is done.

My thinking to date on this is based on the following:
1.) cost to convert to FAG with A/C will be less expensive than replacing boiler and adding more rads and separate central a/c.
2.) FAG heats the zones faster than hydro.
3.) No more monster rads in the house
4.) Ability to improve air quality with FAG system

My existing attic is open and the existing basement will be gutted so venting to the first floor should not be too problematic. Existing second floor will most likely have to be accessed by ceiling vents.

Anyway has anyone had any experience with this sort of job? Do you think I am on the right track? Opinions and options about my plan would also be appreciated. Sure I would love radiant floor heat and skypack a/c but the lottery ticket has not come in, so please lets keep the $$ as a primary consideration.

Thanks in advance for your opinions and insights.

[millerman]

First step would be to call a quality HVAC contractor or two at most (you may get confused with multiple bids). With plans in hand have the contractor do a complete load calculation of your home including addition. Then they should provide you with equipment options etc. and a quote. Keep in mind a retro from hydronic to forced air can and will be fairly expensive if done properly and there is no way we could even begin to give you estimates nor ball park figures, #1. its against the rules for this site and #2 we have no way of knowing the ins and outs of getting ductwork to various parts of your home. Good luck in finding the right company, that will determine wether you get a system that functions properly or one that leaves you uncomfortable and wearing parka's in the winter or running fans in the summer.

[casturbo]

Originally posted by camshaft
My current home is 1600 sq ft, 2 story double brick construction (circa 1939)located in Southern Ontario. Next year I am planning a 1100 sq ft 2 story addition. Currently have a NG boiler / cast iron rads. Boiler is 26 years old. No A/C in the house.

I am considering changing to a gas forced air system and removing the old equipment and rads. I do want A/C included when the addition is done.

........so please lets keep the $$ as a primary consideration.

No doubt, if you need to revamp a heating system AND want A/C someday, forced warm air is the least expensive. Builders love to install forced air systems because of this.....do realize, however, these same builders typically don't put forced warm air in their homes. They usually do a hydro-air system or hot water baseboard heat with separate A/C. Comfort with forced warm air is usually not on par with the other types of heat....it takes carefull installation and setup to make a forced warm air system equivalent to the other types of heat.

[camshaft]

Millerman thanks for the insight. I did not however ask for any pricing or estimates. My post is more about what is the best thing to do based on my situation. Cost overall is a concern, when isn't it?

[johnsp]

You want cheap, sure go hot air. I guess in Canada you guys have plenty of gas so the price is not going up. But you're gonna have to do duct work from basement to the 2nd floor for one furnace. With hydro, you can have 2 air handlers (with 2 smaller ac systems) for better zoning control. I don't think 2 furnaces would cost less then 1 boiler if you wanted seperate systems.

Where do you come off with hydro air not being as warm?
Why do you want a blast of hot dry air instead of steady warm air? With hydro you still can install humidifier and air cleaner so why is it less healthy?

If cost was an issue I'd do it in stages. Simple ac split system in attic for 2nd floor. Pipe the addition for baseboard or pannel rads first. Change boiler following year (Probably oversized and can carry you one more year).

[camshaft]

Johnsp I did not say one was warmer than the other. I have found that hydro takes LONGER to bring a room up to a comfortable temp than forced warm air. Nor did I say hydro was unhealthy. I do appreciate your opinions though. Thanks.

[johnsp]

Longer is better. One of the advantages of hydro is you can vary the water temp and keep the blower running longer but slower so you get more even heating. You shouldn't notice that the heat is on in a well designed system. A better hydro air handler will have an aquastat on the unit and only turn the blower on once the water has reached a minimum temp, so no blast of cold air waiting for the hot water to reach the unit.

I don't see how blowing dust around a room and drying out the air is healther with hot air? That's why you have to humidify and filter. Sorry, I'm just a big hydronic heating supporter.

[camshaft]

So, with hydro-air I may well be getting the best of both worlds. I could have radiant floor heating in the basement slab, foyer, and bathrooms. warm air with one or more air handlers and of course the A/C. Future possibilities including snow melting in my driveway...Plus now I also get domestic hot water as well. All from one boiler. Hmmm.

Has anyone had any experience installing this type of system into a renovation/addition such as I am planning? I am not asking for a price but would this system be twice as expensive as a forced warm air and furnace as I had previously proposed or more?

[johnsp]

Yes! You've seen the light. Sure it will cost more. Double? It depends on how high tech you go. To be fair, you'd have to compare it to 2 FHA/AC systems assuming you'd want the same level of zoning. Like I said, the best part is you don't have to do it all at once, and you can make hydronic heat act like forced hot air if that's what you want.

Your ac needs are not that great and the 2nd floor will probably be the hotest and need the quiest system for the bedrooms. Put a simple attic ac split system up there for the 2nd floor. Your 1st floor might make do with a ductless mini-split. No expensive alterations or loss of closet space to ductwork.

[Edited by johnsp on 10-26-2005 at 03:51 PM]

[Christheheatingdude]

I recently had a customer approach me with the same idea. After the unseasonably hot summer we had, they wanted to remove the oil boiler, and install forced air.

I advised against it. Radiant heat, be it from floor, radiators, baseboard is the most comfortable compared to forced air.

We proposed updating the current boiler(kept oil) and installing mini splits for a/c. The homeowner was very pleased, and it actually came in less than a totally new forced air system.

Your situation is a little different, being that you have cast iron rads. However, I would still advise staying with hot water heat. The options a boiler gives you are worth it. Like has been said, radiant heat, domestic hot water, hydro air handlers, and baseboard where necessary.

[flange]

being an owner of an hvac co, i wanted the best of both worlds. when i was shopping for my current home there were some things that were absolute necessities. one major point was seperate sytems, that is, boiler and some form of hydronic heat along with ducted central air. this is the best of both worlds in my opinion. if you ve got hydronic now, keep it and add ac. if you are doing remodel, you may want to consider radiant.

[Roscoe]

Originally posted by flange
being an owner of an hvac co, i wanted the best of both worlds. when i was shopping for my current home there were some things that were absolute necessities. one major point was seperate sytems, that is, boiler and some form of hydronic heat along with ducted central air. this is the best of both worlds in my opinion. if you ve got hydronic now, keep it and add ac. if you are doing remodel, you may want to consider radiant.

Ditto:
I am also an HVAC contractor, hydonics is by far the better heat just add A/C and look into radiant for that addition. If you want comfort.

Why is warm air cheaper to install, it's not as comfortable and cost more to operate, but it's cheap

[royboysc]

Last winter I replaced my hydronic coil in my air handler with a American Standard (Trane) Freedom 90 2 stage furnace. The reasons were economic. Boiler worn out and tired of repairing leaks from old age. The fuel savings were great but to be thoroughly objective, the boiler was old and the newer boilers have much better efficiency. Overall I'm happy with the new setup. Heats the house up very quickly.