Tag Archive for: heat pump

All of them? Yes, all of them. Even the one in the bathroom that is always freezing cold? Okay, you can close that one.

Depending on many factors, the cost of heating and cooling your home can be responsible for as much as half of your electric bill. At Mode Comfort & Air Quality, we are often asked by homeowners what they can do to lower their energy costs and increase the efficiency and lifespan of their comfort systems. The first response to this question is another question:

Are all of your vents open?

You likely have a return register that is non-adjustable (just a grille), but your supply registers (through which air gets pushed through the house) will have a means to adjust them. It seems perfectly logical that if a grille is adjustable (like window blinds), then you should be free to adjust it, and many people do just that.

Wait, are you saying I shouldn’t touch the lever on the vent cover once it is opened?

Closing even a few vents can cause problems for your system. Issues can be minor, such as low air flow or condensation, or major, such as a dead compressor or a cracked heat exchanger.

Many homeowners tell us that they thought that by closing a vent or two in an unused room they were asking the unit to “work less.” The marvelous world of HVAC does not work this way. By closing vents, you are actually restricting the duct system by increasing the pressure in the air ducts, which could cause leaks. Believe me, no one wants leaky ducts. Energy Star reports that “In a typical house, however, about 20 to 30 percent of the air that moves through the duct system is lost due to leaks, holes, and poorly connected ducts. The result is higher utility bills and difficulty keeping the house comfortable, no matter how the thermostat is set.”

Here is the technical part, in case you like numbers.

Air conditioners have to move a certain amount of air all the time. For instance, a 3-ton air conditioner is designed to move 400 cubic feet of air per minute (“CFM”). This flow can be raised or lowered 25 CFM without much impact on the unit (such as closing the vent in the bathroom that is always freezing…but just that one). A typical residential 6-inch metal vent moves 100 CFM. If you have a 3-ton AC and close off four vents, you just turned your 3-ton unit into a 2-ton unit. Thus, losing a third of the effectiveness (having a really dirty air filter can do the same thing).

Worst case scenario

Closing vents also causes the blower to slow down by restricting where the air can go. This can cause the evaporator coil to freeze, which will eventually destroy the compressor in the outdoor unit. Low airflow may also cause the heat exchanger to overheat, which could lead to a crack that potentially releases carbon monoxide into your house.

Final words

We suggest that you open your vents (but you probably figured that out by now), open your interior doors, change your air filters regularly, and let your HVAC unit work as it was intended. We go on many service calls that could have been avoided. At Mode, we are always happy to answer your questions and help you avoid costly repairs to your system.

When we go to a client’s home to quote an equipment replacement, here are the things we look at:


  1. What is the type and size of the equipment currently installed, if any?
  2. Why are we replacing the equipment? Is it because it is old and the client is being proactive (not usually the case)? Has the unit has been riddled with issues (if so, we need to find out what the issues have been)? Is the equipment not performing correctly (if so, why)? Is the unit just not worth fixing (we also need to know why)?
  3. Then we look at the details. Is the unit sized adequately? Are there any issues with the duct work? Was the current system applied and installed accurately (how do we rectify this)? Is the current system code compliant (if not, we must figure out how to make it so)?
  4. We also need to know what the client wants and expects. High efficiency? Reliability? Simplicity? We have to determine what brand will best suit their needs. We also have to figure out how to best adapt the existing duct system to work with the new higher efficiency equipment.
  5. Once we have answered all of these questions, we present an estimate based on those answers. We devise our recommendation from decades of experience, knowledge of the industry and its products, the latest in industry news and training…lots and lots of training.


When you buy online, they say you eliminate the “middle man,” but that is not true. You simply exchange one for another. You remove the person who has spent thousands of hours immersed in the industry; the person who will actually come to your home and make a customized suggestion; the person you can call on if there are issues; the person that has built relationships with local vendors; the person that will stand by his/her work; the person who has invested hundreds of thousands of dollars in his or her business; who has spent thousands of man hours on the job and in training to master his/her trade.


What you will get is an online retailer who will assign you a customer number and has no real qualifications other than shipping boxes. Admittedly, I have very little experience with shipping boxes.

Most, if not all, online retailers offer installation. They pay very little to the subcontractors they hire. Generally, you will end up with a new contractor; or one that is just “getting by”; or a contractor who relies on volume and not quality to pay the bills; or maybe a contractor with no customer service skills, so he relies on others for his/her customer base. Hopefully, the contractor they hire will have a business license and insurance, but that is not always the case. The online retailer will accept no responsibility for anything other than shipping the equipment to you or their contractor. Most reputable, well-established contractors will not install customer-provided equipment. It is often not worth the headaches involved.


Online retailers say that the units come with a factory warranty. This is true and false. Local equipment distributors depend on sales to contractors for their income. Anyone without a proper contractor’s license that attempts to obtain parts from a local vendor will be denied. Online retailers are the competition and the brick and mortar distributors are not going to help them – or their customers out. For warranty purposes, equipment serial numbers can be traced back to the original seller, despite what anyone tells you. The distributor will be able to tell where your equipment came from. So, even I, with my four Master Tradesman Licenses and my contractor’s license, will not be able to buy parts under warranty to fix your unit purchased from an online retailer. You, the buyer, not the contractor, will have to go to the original online seller to get the components you need for the repair. If the original equipment arrives damaged, you will have to contact the seller to get new equipment. Some manufacturers will go as far as to completely void the warranty if purchased online.


Unfortunately, many people find this out too late.

Yes, you can save money on the initial purchase, but the costs that you may incur later as a result of lost time, frustration and correcting shoddy workmanship will greatly overshadow any potential savings. In the end, as with most things, you get what you pay for. You can save a little money up front and risk potentially paying dearly in the future, or hire a reputable, local contractor to take care of everything for you and rest easy.