PickHVAC Tips: First, see the PickHVAC tip above about sizing a central air conditioner. It applies to heat pumps just as much. Secondly, Even if the line set for the new heat pump is the correct size, we recommend replacing the set or at least the fittings. Old lines and fittings are a major source of leaks. When refrigerant leaks out, the heat pump efficiency suffers. Eventually, the unit stops providing heating and air conditioning, and it might break down.


I have lived in Calgary for quite some time now. When I first moved here I couldn’t stand the humidity levels. Its like a desert come winter. When I first moved into my new home, the house inspector insisted I have my furnace and ducts cleaned. I was very sceptical about duct cleaning to begin with. The company I hired came on time and were very respectable from the start. Before mentioning anything they asked me what my concerns were and what issues I was having. They were more concerned about addressing my issues then bringing anything non related up. I ended up going with this company and getting a humidifier installed a couple days later after the cleaning. Its been almost 4 years now that I have been here. The humidifier is working great and the difference is incredible. They took me around explained step by step what they were doing and the reasons they were doing it. With all those other companies out there, I am glad I found them at this site.
Heaters are appliances whose purpose is to generate heat (i.e. warmth) for the building. This can be done via central heating. Such a system contains a boiler, furnace, or heat pump to heat water, steam, or air in a central location such as a furnace room in a home, or a mechanical room in a large building. The heat can be transferred by convection, conduction, or radiation.
Mitsubishi Electric is a world leader in air conditioning systems for residential, commercial and industrial use. Challenged to create air conditioning systems that provide exemplary performance in the wide-ranging climatic conditions found throughout Japan, our engineers develop amazingly sophisticated yet durable units and systems capable of constant use under virtually any natural climatic condition on earth.
Typically speaking, the lower SEER, more basic models are also more reliable.  Reliability is big with us, so we steer clear of features with reliability issues, and it’s as simple as that. When you factor in the price of repairs and the extra expense of the 21-SEER, you may actually lose money! 16 SEER is the sweet-spot, and it is key to reducing your HVAC installation cost.

They did come out Tuesday and completed the job.  We called the office to ask for a breakdown of the cost and they said the tech would call us back, but that never happened.  Eventually Alberto called and explained the breakdown.  One reason it was more was they used an OEM circuit board, rather than an aftermarket part.  I agree with this but it would have been better if this had been explained from the beginning.  All in all, it still seems like their price is a bit on the high side, but they did a good job and used OEM parts so I'm giving them four stars.


Natural ventilation is the ventilation of a building with outside air without using fans or other mechanical systems. It can be via operable windows, louvers, or trickle vents when spaces are small and the architecture permits. In more complex schemes, warm air is allowed to rise and flow out high building openings to the outside (stack effect), causing cool outside air to be drawn into low building openings. Natural ventilation schemes can use very little energy, but care must be taken to ensure comfort. In warm or humid climates, maintaining thermal comfort solely via natural ventilation might not be possible. Air conditioning systems are used, either as backups or supplements. Air-side economizers also use outside air to condition spaces, but do so using fans, ducts, dampers, and control systems to introduce and distribute cool outdoor air when appropriate.
DIY: We don’t recommend a DIY approach. Depending on the system, working with gas, electricity and refrigerant create dangers. Beyond that, it is essential that split system components be selected for compatibility. DIY installation of an HVAC system will void the warranty of most brands. The manufacturers won’t stand behind the warranty when anyone other than a certified installer does the work. This is true since improper installation is the main cause of poor system performance and mechanical breakdowns.
PickHVAC Tips: Electricity resistance heat is the most expensive heating type. You don’t want one of these unless you’re heating less than 30 days per year. The upfront cost of an electric furnace is much lower than the cost of a gas furnace. However, operating costs are two to three times higher. If winters are cold where you live, you’ll waste your upfront cost savings in just a few years of high electric bills.

Well, I had the cleaning done. The handler is definitely much quieter. It was explained to me that with the coils clean, the condensation will be able to sweat off instead of sticking to the dust and dirt, therefore the humidity (lots of humidity in florida) will be removed better. I feel as if it was worth it, but, I will definitely change that filter every 3 weeks or so from now on. I don’t want to pay that cost again.


I hope that those customers you have with breathing problems don't follow your advice too closely. You are doing them a disservice. Dirt in your ducts does not always stay there, depending on what the contaminants are. I bet you tell your customers not to worry about mold either- just to kill it with bleach. Educate yourself before opening your mouth- You may kill someone someday with your opinion.

I even asked if this is something they don't do, as in services on a Saturday night.  I was told by the receptionist that they do and I would just be ok calling another company if they is not  part of their services. They again assured me someone WILL call me in 10 mins.  Well, unless their definition of 10 mins is never, then they got it wrong as I am still waiting to be called 5 days later.


I had my ducts somewhat cleaned December 22, 2014. The hose of the machine the technitian used did not fit in some of my vents, therefore, he did not clean them. But I still paid $428.00 for the service. I will be calling the company on Monday, and kindly ask them to come back and clean the ducts they did not as they did not fullfill their part of the service.
I was with you until you said avoid steaming cleaning or moisture, there is no way you can remove mold or any other type of biological without moisture. The best way to do this is in fact with a steamer using a commercial disinfectant and a non reactive odor remover so your home smells refreshed and not like a hospital . This is directly contradictory to your article.
in response to this reply " should your ducts be cleaned", i have to politely correct the person who answered this. you are not using common sense. first, most of the country uses metal duct work, so for you to say what you did, is wrong. second, the duct system in a house is a circulatory system. that means it draws air into the furnace, it gets filtered, and then it is blown out into the house to heat or cool. So, obviously that air is being brought into the house from somewhere right? Yes, its coming from the outside where there are many allergens and dust particles . For you to says that about whether a duct system is sealed or not, makes no difference. The air is coming from somewhere right? It has to originate from somewhere right? Just look on top of your cieling fan. If there is a bunch of dust up there, then there is obviously a bunch in your ducts. And the duct air is being circulated every day, and every hour through your house. Its simple, dust collects everywhere in your house. Imagine if you never dusted your shelves, or tv? There would be a ton of dust after a while. Well, now think about the air in the duct system. Of course theres gonna be a ton of dust in there. For you to say that it is not benififcial to clean the ducts, is plain ignorant. 90% of the air we breathe is in our household. Wouldnt you want that air to be as dust and allergen free? I could go on for hours about the benifits of duct cleaning, but i just wanted to make a quick point that the person whose says it is not benificial to clean them, is not using common sense. Not to mention, giving the people who clean ducts for a living, a bad name. Use your head .
I purchased a Groupon for cleaning of unlimited air ducts and one return vent for $39. I should have checked into their hours first because they only offer services during normal business hours. So, with no evenings or weekends available you have to take time off work. I asked Groupon for a refund when I realized this and they refused because it wasn’t within the three day window. Then they didn’t even show up or call for the appointment. I called them after they were an hour late and they were going to call the local dispatch office and have them call me back within 15 minutes. I did not receive that call. I called again and was told I would get a call back from a manager. That didn’t happen either. So I asked Groupon for a refund again and they gave me Groupon bucks. When the survey came asking if I was satisfied with the Groupon customer service I said no, I want real money. I got my real refund the next day. Seems to me Groupon should stop dealing with these companies.
An important component of natural ventilation is air change rate or air changes per hour: the hourly rate of ventilation divided by the volume of the space. For example, six air changes per hour means an amount of new air, equal to the volume of the space, is added every ten minutes. For human comfort, a minimum of four air changes per hour is typical, though warehouses might have only two. Too high of an air change rate may be uncomfortable, akin to a wind tunnel which have thousands of changes per hour. The highest air change rates are for crowded spaces, bars, night clubs, commercial kitchens at around 30 to 50 air changes per hour.[17]
Metal is way better than flex duct or ductboard. It gets better airflow, holds up to critters and duct cleaners. I know of no hvac company here that cleans ductwork. (there probably is one somewhere) The mfg's of duct cleaning equipment keep trying to sell us hvac people on their benefits and profit potential but most all hvac people know that unless you have metal ductwork you are NOT doing the customer any favors.
No matter where you bought your air conditioning system, we can repair it. We have years of experience working with all the best central air conditioner brands such as Kenmore, Carrier. Trane, Goodman, and Rheem. As a result, you can rest assured we’re familiar with your air conditioning system and we have the parts you need to complete a successful air conditioner repair.
Air duct cleaning service providers may tell you that they need to apply chemical biocide to the inside of your ducts as a means to kill bacteria (germs) and fungi (mold) and prevent future biological growth. They may also propose the application of a "sealant" to prevent dust and dirt particles from being released into the air or to seal air leaks. You should fully understand the pros and cons of permitting application of chemical biocides or sealants. While the targeted use of chemical biocides and sealants may be appropriate under specific circumstances, research has not demonstrated their effectiveness in duct cleaning or their potential adverse health effects. No chemical biocides are currently registered by EPA for use in internally-insulated air duct systems (see Should chemical biocides be applied to the inside of air ducts?).
They did come out Tuesday and completed the job.  We called the office to ask for a breakdown of the cost and they said the tech would call us back, but that never happened.  Eventually Alberto called and explained the breakdown.  One reason it was more was they used an OEM circuit board, rather than an aftermarket part.  I agree with this but it would have been better if this had been explained from the beginning.  All in all, it still seems like their price is a bit on the high side, but they did a good job and used OEM parts so I'm giving them four stars.
The short answer is yes, duct cleaning, done right by a reputable company will help with the smell. It is likely though the smell is coming from another source, ie the crawl space. It could also be that another rodent is dead in the duct work. A visual inspection would be in order to check for any breach in the duct system. A duct pressure test would be able to tell you how much air is leaking from the system over all. A hole large enough for an animal to enter would loses a great deal of air, over 300 CFM. It would be worth looking into having this test done and it should cost around $200. Cleaning the air handler and evaporator coil will greatly improve the performance of the air conditioner. Dirt and dust on the evaporator acts as insulation and reduces the amount of cooling done be the coil. Any quality duct cleaning should include cleaning the air handler and coil, and the tech should allow you to watch him perform the work as it is done.

If there is stuff in the ducts, the fact that it’s laying there and not being blown into the rooms is proof positive that it is hurting no-one. The 5-6 exceptions you cite in this article I’ll buy, but only with the caveat that at least some of those could have been avoided by proper protection (during remodeling for example) – and if asbestos/lead/whatever winds up in your ducts- the remodeling contractor should be the one paying to remove it.

If you’re anything like most of our readers, you’ve spent hours online researching HVAC information in preparation for replacing your old heater or air conditioner. I’m the same way; it’s a big investment! You may want to consider saving yourself some time and money by getting an HVAC-Facts Report from this online HVAC installation cost calculator.  Take a look:


I live in a 1950's ranch house in the South. The prior owners were smokers. Based on recommendations from one of the local conservation organizations, I decided to have a home energy audit done. As part of their findings, they recommended additional insulation in the attic and duct cleaning and sealing. This turned out to be a very problematic process. In terms of the ducts, it was necessary to remove the metal grates. However, these grates had been painted over many times and shoe molding covered the bottom of the grates. The vendor was not able to remove the grates without damaging them in the process. Because these grates dated back to the 1950's, it was difficult to find appropriate replacements. The ones I finally discovered were correct except they were 1/4" wider. This meant that the shoe molding had to be carved out. The duct cleaner could not provide any assistance with this problem. It took me a month of long evenings replacing the vent covers myself, carefully chiseling out the shoe molding and repainting. In terms of the extra installation in the attic, the same vendor used blow in insulation. Unfortunately, they did not recognize that the 13 floodlights whose mounting extended into the attic were not designed to be buried under insulation. The problem manifested itself in terms of expensive flood light bulbs failing continually. So, I had to have all of the light housings replaced. Yet another unexpected expense. Despite the expense, pain and suffering, I cannot report any improvement in my heating costs or the "quality" of the air. To be fair, I do not have any allergies and did not undertake this for air quality improvements but rather heating efficiency improvements.
If you are replacing your air conditioning system, make sure that the unit is the proper size for your needs and that all ducts are sealed at the joints. A unit that is too big will cycle on and off frequently, resulting in poor moisture removal, particularly in areas with high humidity. Also make sure that your new system is designed to manage condensation effectively.
Contact/Relay -- Relays are electronically controlled switches that activate the various components of your HVAC system. They manage everything from the power going to the motor to automatic dampers, humidifiers, etc. Most of them are controlled by the thermostat. The most common failure for a relay is being stuck in the "open" position. Separated from its assigned contact point, it fails to complete the connection and send the message to whatever it was supposed to operate. This failure usually occurs from use over time. Each time a relay connects and sends its signal, the electrical arcing from point to point eventually causes wear and tear.
HVAC is an important part of residential structures such as single family homes, apartment buildings, hotels and senior living facilities, medium to large industrial and office buildings such as skyscrapers and hospitals, vehicles such as cars, trains, airplanes, ships and submarines, and in marine environments, where safe and healthy building conditions are regulated with respect to temperature and humidity, using fresh air from outdoors.

PickHVAC Tips: Electricity resistance heat is the most expensive heating type. You don’t want one of these unless you’re heating less than 30 days per year. The upfront cost of an electric furnace is much lower than the cost of a gas furnace. However, operating costs are two to three times higher. If winters are cold where you live, you’ll waste your upfront cost savings in just a few years of high electric bills.


All of you have dentists, you have doctors, you have preachers, you have mechanics. You don’t have to know everything about everything but you have to have people in your life that you can trust. Don’t just open up the phone book and pick a mechanical (HVAC) contractor. Call your friends and family and ask for referrals. There are no black and white (scam or not a scam) answers here.
An air conditioning system, or a standalone air conditioner, provides cooling and humidity control for all or part of a building. Air conditioned buildings often have sealed windows, because open windows would work against the system intended to maintain constant indoor air conditions. Outside, fresh air is generally drawn into the system by a vent into the indoor heat exchanger section, creating positive air pressure. The percentage of return air made up of fresh air can usually be manipulated by adjusting the opening of this vent. Typical fresh air intake is about 10%.
The cooling coils the air comes into contact with appear to need UV-C lights on them in humid climates. That's the biggest thing. If the ducts have never been cleaned, then getting that done goes without saying. But those coils need to be cleaned, disinfected, and then UV-C light(s) installed to prevent mold & bacteria build-up in the future on them. That appears to be chiefly responsible for the dirty laundry and/or sour milk smell coming from forced-air AC systems in humid regions.
Air conditioning and refrigeration are provided through the removal of heat. Heat can be removed through radiation, convection, or conduction. Refrigeration conduction media such as water, air, ice, and chemicals are referred to as refrigerants. A refrigerant is employed either in a heat pump system in which a compressor is used to drive thermodynamic refrigeration cycle, or in a free cooling system which uses pumps to circulate a cool refrigerant (typically water or a glycol mix).

HVAC System Quality Installation Contractor Checklist -- This checklist identifies all of the steps the contractor has taken for the Energy Star Certification and identifies what work the contractor has done. If the system is later modified, this checklist can help identify what was done to proper Energy Star specifications and what was added later that may not meet the requirements.
Many disconnect blocks contain two cartridge fuses. Check them before you proceed with repairs (Photo 3). A blown fuse is a sign of a failing part inside the condensing unit. So don't just replace it and think you've solved the problem. Instead, replace the parts we show here. Then install new fuses and fire up the unit. If it blows again, call a pro—you've got more serious issues.
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