TAMPA, FL — This part of the United States is particularly well known to tourists. With beautiful beaches, glorious gardens, and a marvelous mouse nearby (Mickey, that is), people from all over the world flock here.

Some decide to call the city home, rather than just visit once or twice a year to soak up the sunshine. One of those fortunate residents — a doctor and his family — is in the process of building a spectacular home, which has an equally amazing HVAC system. At 15,000 square feet, this home will provide more than enough room for its occupants.

Given the hot and humid conditions in Florida, it’s no wonder that the owners wanted to spare no expense on comfort. The result is an HVAC system that’s sure to keep them comfortable no matter what the weather decides to do.


The contractor on the job is Shawn Mercado, the owner of MercAir in Tampa, FL. He’s intimately familiar with the special needs of custom homes; he specializes in this niche market.

He estimates he’s involved in about four custom homes a year, but most of these are nothing like the mansion he’s currently working on.

“The total house is 15,000 square feet, with about 12,000 square feet of living area. I’m in the process of putting in eight 14-SEER Ruud heat pumps with variable-speed air handlers. We’re also installing Trol-A-Temp zoning. It’s going to be really nice — a Honeywell S200 filtration system, digital programmable thermostats, remote sensors — the whole nine yards,” says Mercado.

Eight heat pumps are being installed in this 15,000-square-foot home in Tampa, FL. The home will need several mechanical rooms, including a 5- by 10-foot room on the third floor for three of the air handlers.
The owners were certain they wanted heat pumps, which Mercado was happy to hear. “I’ll sell them whatever they want, but a lot of times people put gas furnaces in tract houses, and I don’t understand that. In Florida, you have nine months of summer and three months of winter, and most people only put the heat on for maybe one full week. Why have a really efficient heating system and a not-so-efficient air conditioning system?”

Originally, Mercado quoted 12-SEER heat pumps, but citing a concern over efficiency, the owners opted for 14-SEER equipment instead. The eight heat pumps total approximately 19.5 tons.

“That should be plenty to take care of humidity,” he says. “We went with variable-speed air handlers because they take out a lot more humidity than just your standard blower. We’re also putting in five barometric bypasses.” These will allow excess air to recirculate when static pressure is high, which is easier on the ductwork and will also dehumidify the house more quickly.


In addition to the heat pumps, the owners also wanted zoning, which makes sense for a house this large. There are eight zones, including one to service the playroom over the garage. Five of the zones (with the exception of the one over the garage) will have motorized dampers.

The benefit of these dampers is energy savings, says Mercado. “If they’re not using certain rooms and they’re all in the living area, for example, the dampers will close the airflow going to rooms that are not being used and push the air into other rooms that are being used.”

The question remains whether or not the homeowners will understand how to program the zones in their home if a change is required, but Mercado is doing everything he can to make it easy for them. “I’m going to make a little pamphlet for them, and I’m going to color-code all the zones. The way it’s set up with the Trol-A-Temp system, it doesn’t take a rocket scientist to figure it out.”

With all the equipment going into the house, several mechanical rooms are a must. Mercado says he’s been working with the general contractor and architect to ensure there’s enough room for all the equipment. He is particularly pleased that the second-floor mechanical room was recently relocated to the third floor. “We needed at least a 5- by 10-foot room for three of the air handlers, and we got it.”

The original design called for one second-floor closet to contain two of the air handlers, as well as other equipment such as motherboards. With the third-floor mechanical room, Mercado will have a place for all of the dampers, motherboards, and controls, along with the associated air handler. “It doesn’t make sense to run a lot of wires somewhere they don’t need to be,” he says.


There’s no finish date yet for this house, and there is definitely more work for Mercado. That’s because after the initial bid was made, he sat down with the homeowner and discussed the benefits of comprehensive filtration and ultraviolet (UV) lights. The homeowner wanted the filtration, but not the UV, so Mercado needed to write up a change order for the filters.

“It would have been smoother to have that conversation with the homeowner to begin with, so I would’ve known exactly what they wanted. But we’ll get everything done. The general contractors and the homeowners have been great to work with,” notes Mercado.

And when it’s all finished, this multi-million dollar house will have an HVAC system that will keep its occupants supremely comfortable.

Publication date: 08/19/2002