How Can I Maximize Efficiency From My HVAC System

In a commercial HVAC system:

1. Head Pressure: Add a water regulating valve to each individual Heat Pump. By doing this addition we can increase and maintain the head pressure @ 110 degrees F and run the unit to its maximum efficiency. This has the potential to decrease energy consumption from the unit by 10%-20%. In addition to maintaining our head pressure, we also reduced the amount of water supplied to all units. This will increase the life and efficiency of your water loop water pumps.

2. Water loop Temperature: Your water loop temperature should be between 60 - 90 degrees F. The optimum water temperature is 80 degrees F. Maintaining your water loop temperature at 80 degrees will keep your heat pumps in their optimum working conditions. This will also help with nuisance issues (such as heat pumps tripping out on high head).

3. Filter Changes: Your filters need to be replaced as often as 2-3 months. My professional suggestion is to use MERV 8 standard cap filters, these provide the most protection from dirt and dust without putting a load on the indoor fan motor. Efficiency may drop by up to 20% due to dirty filters or clogged evaporator coils.

4. Digital Thermostats: New digital thermostats can provide 1% energy savings for every degree of temperature change for an 8 hour period. Ex. (thermostat dropped 3 degrees over 8 hours, this equates to 3% energy savings). These savings are easily attained as we program all thermostats to have a night set back (Generally these set backs last 8-12 hours). New thermostats have more aggressive algorithms programmed into them, this gives us a more precise temperature control and more savings. New thermostats also have an intelligent recovery system, this allows the thermostat to learn your HVAC equipment and the time it takes to cool/heat the surrounding area (More savings). The thermostats that we use, also come with a digital lock code (4 numerical inputs), this allows us to get rid of those ugly thermostat lock boxes.

Estimated Cost for Changes:

          Head Pressure Regulating Valve (Installed and adjusted)                    $ 600/unit*
          Digital Thermostat (Installed and Programmed)                                     $ 550/unit*


          *The above prices are a rough estimate

 

SUMMARY:

Coupling all of these methods together in a commercial building, we can expect to see an annual savings of $100-175 per unit per year.

For example, a building with 200 water sourced heat pump units, could potentially save $20,000 - $35,000 per year.

The Importance of Cleaning your Roof Drains

With today's rain warning in Metro Vancouver, we decided to reiterate the importance of cleaning out your roof drains.

These two photos were taken last week, before the rain warning came into affect!  The water that has collected on the roof in the picture on the left has already started to drain down into the customer's interior and needs to be addressed immediately.  This could have been an infinitely more damaging and expensive problem had we not been performing a maintenance inspection at the time!

As a courtesy, whenever Cam Cool visits a customer in the above situation, we take a bit of extra time to clean up the blockage in order to prevent major damage to the building.  It is highly recommended to make roof drain inspections part of your regular maintenance routine to avoid these clogs when the inevitable bad weather hits.  Using a brush or broom, remove any leaves or large debris from the entire roof and flush the drains with water using a hose.  During fall when trees are losing their leaves, and even during winter when there is snow and ice, you should be performing this maintenance task monthly.  During the rest of the year, every three months should be sufficient.

Wearable a/c!

We've had an update to our August 5 blog about a group of MIT students working on wearable body temperature control devices. Their company, Wristify, is a finalist in intel's annual Make It Wearable competition! 

The MIT team's concept won last year's Making and Designing Materials Engineering Contest,  the first prize being $10,000.  As a result of being finalists of Intel's competition, the team has been awarded an additional $50,000 to help make the band a reality.  A prototype version has been developed, and is undergoing tests. 

The winner of the competition will be announced on November 3rd.

We guess it's not as far-off as we thought?!

 

From Wristify:

WHY DOES COOLING THE WRIST REDUCE BODY TEMPERATURE?

  • Wrapping a cold flannel around a wrist is a quick way to cool the body down, because there are pulse points in the wrist.
  • At these points, blood vessels are closer to the surface of the skin than in other body parts.
  • The body's natural cooling system circulates blood to move heat from inside of the body to the surface of the skin.
  • Sweat then helps cool the skin by releasing some of this heat as it evaporates.
  • The blood near the surface of the skin recirculates through the body and absorbs more heat to be released.
  • By placing cold air or bands around these pulse points, it helps the body perform this process more efficiently.

Info Series: Why Does my HVAC Fail?

HVAC failure can sometimes occur due to a bad contactor within your system.  Cam Cool Refrigeration Inc. always checks your contractors for failure.  Keeping up with regular maintenance inspections will ensure that your contactors are always working optimally.

What is a contactor?

A contactor in an air-conditioning system is an electrically controlled switch that turns the unit on and off as required to keep air temperature consistent. It is located in either the indoor or the outdoor part of the unit and consists of a control coil, a metal plunger and one or more sets of electrical contacts.

What does it do?

A contactor is controlled by a circuit which has a lower power level than the switched circuit (Generally 24v). When the control voltage is supplied to the air-conditioner contactor, current flows through the coil, producing a magnetic field. The magnetic field attracts the plunger and pulls it into the center of the coil, causing the contacts to close.

Each set of contacts is composed of one fixed and one movable contact and is referred to as a pole. These contacts are made of steel and coated with silver for better electrical conductivity. When the plunger connects the movable contact to the fixed contact, the electrical circuit is complete, sending power to the air-conditioner components such as the compressor and the condenser fan.

When the thermostat senses that no further cooling is required, the control voltage to the contactor is shut off. When the current stops flowing through the coil, the magnetic field collapses and the plunger is released. The plunger springs back into its normal position and opens the contacts.

An air-conditioner contactor can fail either mechanically or electrically.

Mechanical Failure

Normal mechanical failure is when the contactor "sticks" closed. Signs of this are that the condensing unit (outdoor part of the unit) will not shut off… the thermostat is off, the furnace/air handler’s blower is off but the condensing unit is still running. You will normally find ice covering the refrigerant lines and the evaporator coil. This failure normally occurs when the silver coating wears off of the contacts. An electric arc is created as the contacts close, and without the silver coating, can be welded shut. If the contactor is sticking, it should be replaced.

The contactor may also fail to close if something has gotten into the mechanism to physically prevent it from closing. This is usually caused by dirt, insects or mice.

Electrical Failure

The contactor can fail electrically in one of three ways: the coil can become shorted, grounded, or open.  A multimeter can be used to check for electrical failure of a contactor.

The coil can become shorted when the insulation between the wires in the coil breaks down. This can be found by shutting off the power and taking a resistance reading between the terminals on the coil. The reading should be around 20 ohms, if it is significantly less, the contactor should be replaced.

The coil can become grounded when the insulation on the outer wires of the coil breaks down and allows a path to another metal component. This can be found by taking a resistance reading from each coil terminal to the metal case of the air-conditioner. A low reading means the coil is grounded and the contactor should be replaced.

(In both of these cases, the control circuit fuse on the furnace/air handler control board will probably be blown.)

If the coil is open, the contactor will not close when the control voltage is applied to the coil. This can usually be found by shutting off the power to the unit and the furnace/air handler and taking a resistance reading across the terminals of the coil. If the reading is significantly higher than 20 ohms, the coil is open and the contactor should be replaced.

Cam Cool Refrigeration Inc. always checks your contractors for failure.  Keeping up with regular maintenance inspections will ensure that your contactors are always working optimally.   Call us today to schedule your next inspection.



Source:  http://www.hvac-for-beginners.com/air-conditioner-contactor.html

Old Faithful

This is what HVAC technicians like us want to see more of... a piece of equipment, in this case an air dryer, that is going to last its full lifespan due to proper preventative maintenance.  If you treat your equipment well, it can keep running for up to 30 years!!

This air dryer was manufactured in 1994 - 20 years ago!  It's not the prettiest to look at, but it will keep chugging along for at least another 10 years if proper maintenance continues.

To prolong the life of your equipment, call Cam Cool Refrigeration Inc. today to set up your preventative maintenance schedule.

Filters, Filters, Filters!!

What is an air filter?

An air filter in an air-conditioning system is what traps and removes particles from the air stream before reaching the evaporator coil. It keeps your system clean and running smoothly. It also prevents you from breathing in those bad particles.  Over time, and depending on how dirty the air is (and how big the filter is), these filters become loaded up, restricting the amount of air that can flow through them.

Why change air filters?

Dirty air filters will restrict the air flowing through, putting pressure on your air-conditioning system by forcing it to work harder. A harder working system will result in higher energy consumption and could cause your blower motor to overheat and fail.  It could also cause your evaporator coils to freeze over and shut your system down.

The air that does get pushed through dirty air filters will be polluted and unhealthy to breathe for long periods of time.

Why use a filter at all?

If you remove the air filters from your air-conditioning system completely, the particles that they are supposed to trap will instead build up on your evaporator coil and eventually cause failure.  It is much more cost efficient to change filters regularly!

Here is an example of an air filter that has not been changed in six months. You can see that compared to the clean filter (the white one!) it would be very difficult for air to flow through the particles clogging the almost black dirty one!

When was the last time your air filters were changed?

Cleaning or changing air filters is an important part of preventative maintenance that we perform for our customers.   If you have any questions or if you are concerned that your air filters may need to be changed, call Cam Cool Refrigeration Inc. today to schedule an inspection.