Forced air & hydronics: will the two ever meet?
Roy Collver, Mechanical Systems 2000 Inc., is optimistic that the best of both systems can be wedded successfully in residential applications. As living proof, this manufacturer's rep. from Calgary, Alberta, has designed such a system for his own home. He even has a heated fish pond, a heated driveway and a heated backyard. But he also admits he's unusual in that regard?
For now, Collver said he realizes there are some drawbacks that keep many contractors from delving further into hydronics. On the upside, "radiant floors have energized the hydronics business over the last few years." However, many builders still are reluctant to offer hydronics heating systems in new homes because of cost, "although they will offer granite countertops." Collver spoke at a session on combining hydronic and hvac systems at the Canadian Mechanicals Exposition (CMX) in Toronto.
This is because many consumers, Collver said, still aren't up to speed on what can be gained from a pricier heating system since it is something that is out of sight when they first look at a new home. Also, he said, hydronics systems are more costly and may never be cost-competitive with forced air systems.
Some of that expense, he pointed out, is because many hvac contractors are unfamiliar with hydronics systems. Contractors tend to pad their estimates when they are performing work they are unsure of, and those costs could come down as they work more on such systems and find efficiencies they can take advantage of - such as hiring cheaper, entry-level labor to lay down radiant floor heating pipe.
Of course, hvac contractors will have to expand their horizons and become more adept at plumbing and electrical systems if they want to add hydronics systems to their offerings. This isn't necessarily a drawback, Collver said. "You'll be paid more for your services when you're recognized as an expert" in installing and serving such hybrid hvac systems.
Again, there are advantages that savvy contractors and consumers will want to take advantage of. "Physics is on our side," Collver said. Warm air heating systems need large, ugly ductwork whereas hydronics can move a lot of heat through a small amount of pipe.
Hydronic systems can put heat where consumers want it most, down near their feet. Since warm air rises, conventional forced air systems tend to generate ceiling temperatures higher than floor temperatures, leaving homeowners with cold floors and cold feet.
Some successful town homes are being designed with hydronic underfloor heat on their ground floors or basements, with warm forced air heating on the second floor. While more expensive initially to install, these "combo" systems can produce better comfort overall, Collver said.
Another challenge that will confront some contractors is ventilation. Homes that are heated strictly with a hydronic system still need to be ventilated, especially as concerns over indoor air quality and mold growth continue to surface. Use of a hybrid system makes it easier to prevent stagnant air. Installation of ducts for warm air heating also makes it more practical to have a central air conditioning system since that is also now a "given" for most people buying a new home.