Depending on the size and configuration of the house and the preferences of the occupants themselves, it may just simply be too much to ask one thermostat to keep every room comfortable for every person in the house.
That’s where zoning can offer benefits. In essence, zoning divides a home into areas with similar heating and cooling requirements, and each area has its own thermostat.
In addition to liking the fact that multiple thermostats could reduce the number of arguments in their household, homeowners could also appreciate zoning for increased comfort and potentially lower utility bills. The problem is that many homeowners never learn about zoning, because their contractors don’t bother to tell them about it.
Tincher believes that many contractors don’t offer zoning to their customers because they’re afraid that customers will object to the price. Donnie Broom, president and owner of Midair Air Conditioning and Heating, Fort Worth, TX, agreed with that statement.
“Most contractors do not offer zoning as an option,” he said, “because they are concerned that any other price pressure will cause them the loss of a total sale. They choose to keep the customer focused on what is simply a replacement to what is standard, rather than the benefits of comfort and savings.”
And it is true that zoning does add to the cost of a job. A new home that is approximately 2,000 sq ft would require two or three zones, and the cost for zoning would be around $1,500.
In retrofit applications, the costs can start at $1,500 and go a lot higher, depending on the way the existing hvac system is laid out and how the house is configured. For example, drop ceilings in basements and concrete walls may have to altered, which can drive up the cost.
However, Broom noted that zoning doesn’t always have to add significant cost to a job. “Sometimes the contractor can furnish fewer hvac systems than his competition and more thermostats by using zoning. The difficulty in selling zoning lies with the contractor’s willingness to change his way of selling — to practice estimating and selling zoning jobs.”
“Having zone dampers with thermostats installed in the uncomfortable areas will give the customer complete control,” he said.
Tincher noted that contractors are really missing the boat on zoning, because price is a low priority to the customer. “Homeowners are looking for a reputable contractor, and they’re looking for solutions to their comfort needs.
“Contractors should be offering all these solutions. Most homeowners get upset when they find that zoning was an option that wasn’t offered to them.”
Profit margins are often 10% to 20% when accessories such as zoning, air cleaners, programmable thermostats, and humidifiers are sold with new or replacement heating and cooling equipment. “Compare that to the typical 2% to 5% margin when equipment alone is sold, and you can really start making some noise as far as growing your profit dollars,” said Tincher.
There’s also the benefit to the customer in terms of energy savings. When a zoning system is installed with programmable thermostats in each zone, some estimates show that up to 30% energy savings can be accomplished.
Tincher said that when you take into consideration the installed cost of the zoning systems and your average heating and cooling bill prior to installing the zoning system, a zone system can pay for itself in three to five years, depending on the level of setback and the number of setback modes selected each day.
But before jumping in and installing a zoning system, Broom noted that contractors should turn to manufacturer representatives for help in training their employees.
Zoning “is not complicated once employees understand the reasons that items are installed a certain way,” he said. “We do teach and train with our employees in our shop office with factory people. We also have used videos on zoning. The men then have the opportunity to ask questions.”
Once that’s done, the next step is to size the ductwork to have the appropriate amount of air going into each of the zones.
“Typically in a two-zone system, you’ve got two zones that are about the same size,” explained Tincher. “In that case, you’d want to size those ducts to handle about 60% to 70% of the heating or cooling load from the equipment, so when only one zone is calling, you’re not getting into excessive static pressure and excessive airflow into those zones.”
If more than two zones are used in a house, it’s possible that one of the zones may be very small, such as somebody’s home office. In that case, it’s necessary to make sure that when the small zone is calling for heating or cooling that the equipment is protected, and it’s not setting off a high limit switch or freezing up the coil and causing damage to the compressor.
“In that situation, you’d want to size the ductwork a bit differently, and you’d also want to install a bypass damper so you can bypass some of that excess pressure and start to cool that room down or heat it up more quickly and reduce the amount of time the equipment is on,” says Tincher.
Once the ductwork is laid out, running thermostat wire to the different zones shouldn’t be a problem in new construction, because the walls are open. In retrofit situations, however, pulling thermostat wire can be difficult. Tincher says that the biggest problem contractors have with zoning is simple wiring.
“If you think of your traditional system with one thermostat, you’ve got four wires going from the thermostat to the equipment.
“If you’ve got two dampers and two thermostats and a zone panel, you’ve got at least 16 wires going around the system. Keeping track of them is a challenge. But if you’re very deliberate in doing your wiring, you should be able to get it installed correctly the first time,” said Tincher.
And once it’s done right, your customers will be comfortable and happy, and they’re sure to tell their uncomfortable neighbors, who will probably be calling you to ask for help.