Does your return air grille whistle- Do this to fix it and increase airflow

If you have one of the return air grilles pictured below in your ceiling or wall, listen up.  The fins are angled to hide those ugly filters we put there to keep our coil and air clean.  The downside to the bend in the grille is a reduction in airflow and sometimes a nasty whistle.  Do yourself a favor, go out to a big box store and get a sheetmetal hand seamer tool (or borrow from someone).  Straighten out those grill vents and you will increase your airflow 20% RIGHT NOW.  Don't worry the grille will not break just take the seamers and straighten them out in one motion.  Check out http://www.thermal-medics.com/ for more great DIY and helpful advice.  You can call or email for free your questions, problems or concerns.

How do I know I have a duct leak? The old door trick....

Many times I have walked up to a customer's door, knocked , have the door open, and then either almost had my baseball hat blown off or felt like I was being sucked into a black hole.  What does this have to do with duct leaks you may ask??? Everything, including where the leak is.

Often times a leak is subtle or the home is large, so I use an infrared thermometer to shoot each vent.  I am looking for consistency with slight variation due to where the register is relative to the air handler.  Farther away from the air handler, I typically see a 2 to 3 degree rise in the supply air temp as it travels through the flex.  On a properly charged system I should see a 20 degree split between the supply air (at the register) and the return (at the air filter you hopefully change).  If I come across a grille that is way off, I'm looking at that one for a leak. 

This is where some attic work is required to inspect the flex attachment to the collar.  Often times the equivalent of a zip tie is used to attach the flex duct to the collar.  Over the years the heat, and especially Arizona attics (140 degrees or more), will break down the zip tie and they snap.  The supply air will be blowing all over the place except down the register.  A new zip  and you are back in business.

Return air leaks are a little tougher.  They can show up using manifold gauges (the hoses and gauges we use to check freon levels) but all that says is you have high pressures or a lot of heat in the system.  Many techs may misdiagnose this as overcharged (too much freon in the system) or go looking for dirty outdoor coils etc...  This is where the door check tells it all.

When you close up all the doors and windows in the house you have a decent seal.  Not perfect and you don't want perfect, you want your house to breath a little bit.  When you crack a door you will feel the airflow.  Which way is it blowing?

If the outdoor air is being sucked in you have a supply line leak and if the air blows out the door than your leak is in the return side.  Here is why.  The attic has louvers and openings in it so it can breath with the outdoor air.  If your return is leaking than the air handler is sucking in hot attic air (in unlimited supply with no resistance) across the coil and blowing into the home.  In a sense pressurizing the home.  The reverse in a supply or cold line leak.  The air handler is sucking in as much as it can because it now has not resistance on the supply side.  It can blow all day into the attic. 

So if your doors are a-whistling you may want to check out your duct work for any leakage.  Now you know which side of the duct is leaking before you climb in that attic.  For more tips and free A/C and Heat Pump DIY and troubleshooting help visit http://www.thermal-medics.com/.

Thinking about a new unit?? LOW BID is not always the best!!

After personally installing a lot of new units I can tell you one fact of life in the HVAC field.  THE QUALITY OF THE INSTALL IS WAY MORE IMPORTANT THAN THE BRAND YOU CHOOSE.  I have seen top of the line Lennox equipment installed so poorly it runs worse than the lowest-end trash you could find anywhere.  Same on the flip-side. 

Phoenix is a hotbed of new installs and competition is fierce.  We experienced an unusually large hail storm in October 2010 that gave a mini-boom to the new install market.  Guys were running around tripping over each other to declare hail damage to your condenser coil and to serve up a new unit ASAP.  Now you can only imagine what a $10 per hour Craiglist ad for installers would do when it met this great demand.  Boom!! Leaky duct work, rooftop units not level etc....

Now, you may be thinking of getting a new unit or units.  There are many reasons, the price of R-22 freon is blasting higher (see blog entry below), your unit is more than 15 years old with a major repair on it (compressor, indoor/outdoor coil, etc), or maybe you just want to cash in on rebates. Great, where to start???

Get bids.....I know it takes time but get referrals, call around, call me, anything but get as many as you can stand.  Do you need financing or can you pay cash?  Cash is king in the new unit business.  Can you buy the unit during the off-season???  July is super busy for everyone and you will get in line and pay a premium but January is dead as a doornail in Phoenix...  Is your unit going to be an easy install?  It makes a huge difference to us, when looking at a job, as to where the existing unit is and how easy it is to access it.  You can remind your bidders of this fact when they show up.  Call me or send me some pics and I can help you out with this..

Beware of low bids and bids over the phone.  You will find most bids within a range of $1000 to $1500 dollars.  If you get a ridiculously low bid, be careful and ask some more questions, there is a reason why.  Check out all bidders license info against the Registrar of Contractors in your state and BBB for open complaints and ratings.  Ask for references on their new installs and call the references to see how they like their new unit.Yelp and most rating sites are so corrupted now, who knows...

We never, ever, bid over the phone.  There are just too many variables we can't account for out there and must see the job in person to be fair to everyone involved.  When you decide on who to go with, both of you should sign the bid making it a contract.  Don't be afraid to ask for some freebies, a touchscreen thermostat, etc.  You are still the customer.

Last but not least is the warranty.  I am not too concerned with labor warranty and at least 2 years should be standard but getting a unit that has a 10 year warranty on parts and the compressor is great insurance in case anything goes wrong with the unit.  Many new units offer lifetime compressor warranties.  Good luck out there and let me know if you have any questions.  I can be reached at my website http://www.thermal-medics.com/.  Last note, some big-box retailers offer displays on new A/C units.  These companies are not always good.  They piggyback on the name of the store but, at least in Phoenix, are way overpriced and do terrible work with tons of complaints.  Just do your research, don't assume they are endorsed by the store and have a clue.....

R-22 vs R-410a

Ok this is a debate that goes way back. Let's give a quick history lesson on refrigerants.  Old man DuPont was said to have been interrupted by an engineer with an interesting discovery. Ammonia would pick up heat and transfer it.  Evaporation and condensation could be controlled in a sealed chamber and used to make ice quickly.  Thus refrigeration was born.

R-22 or known by its trade name, Freon, has been used for as long as I can remember in residential air conditioning units.  Its little brother, R-12, was awesome at small, lower temp, systems like car A/C units.
Well as concern about the ozone layer, global warming etc.. began to take hold there was a call to slowly reduce the amount of R-22 out there.  R-12 had been successfully replaced by R-134 (in your car a/c or refrigerator) so why couldn’t we do the same with R-22. 

DuPont now came up with R-410a.  A blend of refrigerants that is marketed as a "green" alternative to R-22.  You still cannot vent R-410a into the atmosphere and service techs must charge or add the refrigerant in liquid form because it is a blend.  If you add it as a vapor some of the refrigerant will not make it into the unit so you will see techs stand the bottles upside down when charging.

Bottom line.  R410a does work, but the price is higher operating pressures in the system for the same cooling capacity as R-22.  The refrigerant is not what gives your unit the high SEER rating.  It is simply the size of the condenser and if you are using variable speed motors.  We can debate global warming and that would go on forever but the powers that be have just mandated a 45% reduction in the amount of R-22 produced in 2012.  That has made the price of R-22 jump almost 100% in the Phoenix area alone.

It may have to be a factor in deciding what to do with your old unit.  If there are small, pinhole leaks there are products that can self seal in the unit and prolong the life.  If you need more info on these or anything related to A/C or heat pump systems call or email me at http://www.thermal-medics.com/.

Where can I find A/C and heat pump parts?????

Ok, great question.  You can go into the large home improvement warehouses and buy chainsaws, table saws, electrical panels up to 460 volts as well as many home items that will kill you in quick order if you dont know how to use them.

If you go in and ask for a condenser fan motor the guy/gal (if you can find one) gives a blank look and points over by the swamp cooler stuff. They are not there.  The blue home improvement store has a few duct work items including flex duct, elbows, pookie (white mastic for patching leaky vents) but thats it.

So who do I call to get my run capacitor, contactor, condenser fan motor..

Well if you live in the greater Phoenix area go here

http://www.thermal-medics.com/a-c-parts-here/ - A/C and HVAC parts directly to the public for Phoenix, Ahwatukee, Chandler, Tempe, Mesa etc.  Basically call and I will get you what you need with the technical support to get the job done..

In other parts of the country and if you can wait you can try a myriad of online retailers.

follow me at http://www.thermal-medics.com/ to get access to a ton of free diy help and contact info

What the heck is a heat pump?

A heat pump is simply an air conditioning unit that can work in reverse.  Ok, let me back up.  The definition of air conditioning is the movement of heat from somewhere it is not wanted to somewhere else. Where? Who cares just not in our house in Phoenix in July!!!.  That heat that is removed from our comfy homes that we keep at 78 degrees is moved outside through the refrigerant and then transferred out of a condenser coil via the fan.  Have you ever felt how hot the air blowing out of the condenser fan is?  On average it is 30 degrees warmer than the outside air temp. So a 110 degree day in Phoenix will have 140 degree air blowing out of the condenser fan.  Hmmmmm, could be a reason we change so many condenser fan motors in the summer around here...

OK, so if an air conditioner moves heat outside, then in reverse, a heat pump moves heat inside the conditioned space.  The coils (condenser and evaporator) reverse roles and hot gas is redirected indoors (via the reversing valve) during the winter and our cold house air blows across the coil and voila!! it is now warm.

Heat pumps are great but they have their limitations.  If temperatures drop below the mid 30 degree range they start to loose their power.  They need to find heat outside to transfer to the refrigerant and there just is not enough at the lower temperatures.  That is why heat pumps work great in Phoenix but not so hot in Omaha.  Sometime there are heat strips or small heating coils that can provide supplemental heat but by and large gas is the best option in real cold weather climates.

Heat pumps must also have an additional part known as a defrost board.  Over time the outdoor coil will get cold and any moisture will adhere to the coil and freeze.  The defrost board checks the coil temperature from time-to-time to see if it must redirect hot gas to the outdoor coil to melt that ice.  Many problems with heat pumps during the winter revolve around the defrost board and its operation (or lack thereof).  For more tips and help troubleshooting heat pumps and air conditioners or if you want to DIY your next project visit me at http://www.thermal-medics.com/diy-ers/ for more.

Here is a photo of a frosted up heat pump.