# Converting from Forced Air to Radiant Heat



## SJS01 (Mar 9, 2008)

I have forced-air HVAC, which I am not fond of -- particularly with respect to the winter heating aspect. My hot air blower runs on natural gas. I have come to the conclusion that I don't like forced air heating: (i) as soon as the blower shuts off, the temperature plummets, (ii) it is inefficient resulting in high utility bills, (iii) the resulting dry air environment is not good for my lungs. Having spent some time in Europe, I noticed that houses there generally have central radiant heating, generally hot-water based. 

I am toying with the idea of retrofitting my house with central radiant heating throughout. I have the space (including easy-to-access crawl space), and I don't think, other than in a room or two, it will cause any significant damage. I am thinking of installing a combination of baseboards and room radiators. I will not kill the HVAC entirely, as I need the ducts for AC purposes in the summer.

I was wondering if anyone had contemplated or undertaken a similar project, and what your ideas, thoughts or recommendations were, including any alternative you can think of. Your views would be most appreciated. Thanks.


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## pcampbell (Feb 7, 2008)

I hate forced hot air too. Your project sounds like a lot of work. Have you considered direct vented gas (or whatever is convenient) powered space heater / room furnaces?

http://xj.cdevco.net/spaceheat/


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## sgthvac (Apr 15, 2007)

Well here are my thoughts on converting to hot water boiler system. I have a Prestige Triangle 95% efficient boiler with a domestic hot water tank tied to it. I really like it. I also have 5 zones so I can regulate what temps each area in the house. I aslo have worked on several boilers over the yrs. 

The positives are you can get up to 95% efficient boiler since you heat with natural gas which is great efficiency. You will have even heat throughout the whole house without the noise and temp. swings. It is a very nice heat and you can save moneyon your domestic hot water by using the boiler 95% instead of 65% hot water tank.

The negatives, the boiler will still dry out your house and you will have to purchase room humidifiers to add humidity to your home. Filling the humidifiers daily are pain in the neck. It will be an expensive conversion with the price of copper and all the labor tied to installing it. I just dropped $7,000 and I get my pricing at cost. I added one zone and purchased the boiler w/ DHW tank. I did pay my shop to install it (time to do the project). You are probably looking at $25,000 for the job. 

Alernatives, since you are planning to change you system install a hybrid system, 19 seer heat pump with 95% eff. gas furnace with variable speed blower motor. Heat pumps are more eff. than gas furnace and work great down to about 30 degrees. with a thermostat and outdoor sensor you can lockout the heatpump at 30 degrees and bring on the gas furnace. You will have the mild heat on mild days and the warmer heat on colder days. It works very well. The variable speed motor is controlled by dc voltage and acts like a reostat. It operates at half speed when the furnace is not heating so you keep more of an even heat throughout your home and it doesn't feel drafty. 
Do you have the land space for geothermal? 
You mentioned concern about your lungs, do you have a good filtering system for your home? There are poducts out there that can clean your house air with UV bulbs, and an air cleaner to 99% free of dust, germs, and odors that work in conjuction with your blower.

I hope I haven't added more confusion to your decision. Post back if you want to discuss it more.


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## billie_t (Feb 17, 2008)

I am toying with the idea of retrofitting my house with central radiant heating throughout. I have the space (including easy-to-access crawl space), and I don't think, other than in a room or two, it will cause any significant damage. I am thinking of installing a combination of baseboards and room radiators. I will not kill the HVAC entirely, as I need the ducts for AC purposes in the summer.

I was wondering if anyone had contemplated or undertaken a similar project, and what your ideas, thoughts or recommendations were, including any alternative you can think of. Your views would be most appreciated. Thanks.[/quote]

ibuilt an outdoor wood boiler (no pressure) but i still use hot air in the house...i filled the plenum with rads..put a zone valve controlled by a thermostat and my furnace blower is designed to run 24/7 inl ow speed and kick into high when it's thermostat calls for heat...i leave the "real" furnace at 68 and the wood boiler at 72...real furnace never kicks in house is warm and iwhen i added a room with a basement i put radiant heat in the floor


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## Telecommbrkr (Mar 26, 2008)

I have been researching radiant heat for a couple of years and am just dying to install a sytem in my home when funds allow. At today's energy prices, one almost can't afford NOT to put one in. I have found a site that has been of great help in answering alot of my questions: www.radiantdesigninstitute.com . Also for a green alternative to electrically driven heat pumps try www.rohor.com for the ultra-efficient wood boiler by Seton manf. 

Hope this helps...


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