Drop in Refrigerants

There has been a lot of commotion regarding ‘drop in’ refrigerants and I would like to clear some things up. Because of the rising price of R22, refrigerant manufacturers have been recommending an alternative or ‘drop in’ refrigerant. At this time, there is no true drop in refrigerant. Using an alternate refrigerant can reduce the system’s capacity. Famous’ HVAC manufacturers do not support ‘drop ins’ and using it will void the warranty. The only refrigerant that should be used on an R22 system is R22. Yes, R22’s price may go up but it is better to stay with what the manufacturer recommends than to try an alternative. If you need more info on ‘drop in’ refrigerants feel free to call the Famous’ HVAC Customer Support Team – (330) 475-8230.

Jeff Rosenblum
Technical Support
15 Years Industry Experience
Cell (330) 962-2491
jrosenblum@famous-supply.com

Triple Evacuation

Many HVAC Techs have heard the term “triple evacuation”. What is a triple evacuation? Why do it? A triple evacuation is a very simple method of evacuating the refrigerant system. When you connect a vacuum pump to a refrigerant system you are lowering the boiling point of moisture in the system. Sometimes, you can pull a vacuum so fast that it can cause moisture in the system to crystallize and become trapped. An easy way to prevent this from happening is by performing a triple evacuation. A few things you will need are your gauges, nitrogen with regulator, vacuum pump and a micron gauge. Connect the equipment and start the vacuum pump. Allow it to pull the system down to about 4000 microns. Turn the pump off and break the vacuum with dry nitrogen. Start the pump again and pull the system down to 1500 microns. Now, break that with nitrogen. Then run the vacuum pump again and do your final pull down to 400 microns. Remember, the deeper the vacuum the better. The one tool that must be used any time you are evacuating the system is a micron gauge. Without it, we are just guessing. If you need any assistance, please feel free to call the Famous Supply HVAC Tech Support Dept.

Jeff Rosenblum
Technical Support
15 Years Industry Experience
Cell (330) 962-2491
jrosenblum@famous-supply.com

Air in Hydronics

When working with a hydronic system the biggest enemy is air. An air bubble can reduce the amount of water in the pipe and therefore the pipe cannot carry as much heat. When we displace the water we are limiting the amount of BTU’s the pipe can carry. Let’s say a 3/4” baseboard is putting out 550 BTUH at 180-degree water. Now, displace half of that water with air. Your baseboard is now only delivering 275 BTUH. That is a huge difference! There is no place for air in the hydronic system. The more air, the less efficient. Water boilers should be equipped with an air removal device to automatically remove the air. Now that we have covered the piping side, let’s discuss the pump side. A boiler’s pump can only pump water. If we try to pump air the pump will cavitate. This means the pump just spins and does not move the water. Boiler pumps can also be called circulators. Their job is to circulate the water through the system, if air is in the impeller, the pump will not effectively move the water.

Jeff Rosenblum
Technical Support
15 Years Industry Experience
Cell (330) 962-2491
jrosenblum@famous-supply.com

Heat Pump Basics

One of the often-overlooked aspects of installing a heat pump is the location. As a heat pump runs in heating mode it tends to build frost on the outside coil. When the frost gets too thick, the efficiency drops. Because of this, it is necessary to put the heat pump into defrost mode. We do this by reversing the flow of refrigerant. So in heating mode, hot refrigerant is sent to the indoor coil to provide heat. In defrost mode we send the hot refrigerant to the outdoor coil to melt the ice and frost that has built up. When the ice melts we must make sure that the water created can safely drain away. This means, be careful where the unit is located. If it is near a walkway, the water created can drain onto the walkway and refreeze. This poses a danger to the homeowner. Another thing to be aware of is to install the outdoor unit above the snow line for the area. This will help keep the coil clean and the heat pump operating efficiently. This is done through the use of pump-ups or stands. As always, if you need any technical assistance with a heat pump you are working on, feel free to contact the Famous Supply HVAC Tech Support Team.

Jeff Rosenblum
Technical Support
15 Years Industry Experience
Cell (330) 962-2491
jrosenblum@famous-supply.com

What is Draft?

Very often you may be asked to check or verify draft. So what exactly is draft and what does it do? Draft is the chimney’s ability to draw the burnt gasses out of the furnace. Newer high efficiency furnaces don’t have to worry about this but anything that is natural draft or uses the chimney for exhaust should verify proper draft. Typically a proper draft would be around .01-.02”wc (water column) but consult your owner’s manual for the correct amount.

Now that we know what draft is, how do we check it? The easiest way to check draft is to drill a small hole in the flue about 18” away from the furnace in a straight piece of pipe and insert a draft gauge. Some draft gauges use a little Styrofoam ball while others are digital and some use a needle. Once finished checking the draft, make sure you plug the hole in the flue.

So what can affect draft? There are sev­eral factors that can contribute to a low or high draft. The height of the chimney, size of the crock, temperature of the flue, outside temperature, pressure or nega­tive pressure of the house all play a criti­cal role in affecting the draft.

If you have any questions regarding draft please feel free to contact the HVAC Tech Support Team for assistance.

Jeff Rosenblum
Technical Support
15 Years Industry Experience
Cell (330) 962-2491
jrosenblum@famous-supply.com

How to measure CFM using the temperature rise method

A number of years ago, when I first moved into my house, I noticed an issue with my AC unit. When we ran the AC, it would cool ok but it always seemed to be very muggy in the house. I decided to test the CFM of the AC and found out that I had close to 1500 CFM for a 2 ton AC. Knowing that a 2 ton AC only needs 800 CFM, I realized that we had too much air. The problem was that by having too much CFM, the air didn’t have enough time to be in contact with the coil. By slowing down the blower we were able to keep the air in contact with the coil longer therefore causing more condensation on the coil. By having the appropriate 800 CFM, I was able to make the house much more comfortable and reduce the cooling bill. Use the formula below with the blower in cooling speed and see how close your equipment is:

Gas Furnaces: BTU Output/Temp Rise x 1.08

Oil Furnaces: GPH x 140,000 x Efficiency/Temp Rise x 1.08

Electric Furnaces: Amps x Volts x 3.415/Temp Rise x 1.08

By using the appropriate method you can easily identify a lack of or overabundance of air. By changing the blower speed you can then match the appropriate CFM for the size air conditioner.

Matching CFM to air conditioner size can improve its dehumidification and its ability to cool properly. Keep in mind, that proper ductwork is also very crucial in proper operation.

Jeff Rosenblum
Technical Support
14 Years Industry Experience
Cell (330) 962-2491
jrosenblum@famous-supply.com

How to test a pressure switch

To test a pressure switch you must first have a compound pressure gauge (digital or analog).

Tee in a plastic tee for both the positive and negative ports for the pressure gauge, start unit up and observe the reading on the gauge. The reading must be higher than the setting listed on the pressure switch. If the pressure switch only has 1 port then tee in the correct port of the pressure gauge and leave the other port open to atmospheric pressure.

If the reading on the gauge is lower than that of the switch then the problem is in the furnace or venting.

If the reading on the gauge is higher than that of the switch and the switch is not closing, then the problem is the switch.

Jeff Rosenblum 
Technical Support Manager 
14 Years Industry Experience
Cell (330) 962-2491
jrosenblum@famous-supply.com

The Stormy Season is on the Way

We all know how losing power can inconvenience you. The loss of lights, TV, cooking devices, HVAC equipment. Have you ever thought about how much this could cost you? When are you most likely to lose power? In a storm! What would happen if you lost power and your sump pump would not work? This could cause thousands in damage. More and more people are renovating the basement into a living space rather than selling the house and buying something bigger. If the basement is equipped with a sump pump that is one appliance you don’t want to fail.

The current trend in home standby generators is changing from covering the essential circuits to covering the entire house. Famous Supply has Generac generators in stock and can help chose a system that is right for you.

Jeff Rosenblum 
Technical Support Manager 
14 Years Industry Experience
Cell (330) 962-2491
jrosenblum@famous-supply.com

Codes and Changes

You may have noticed a few recent changes when placing orders for HVAC related material with Famous Supply. The Ohio Revised Codes have recently changed and there are a few things that you need to be aware of. Here are some brief highlights of the changes.

  • All new air conditioning systems must now be equipped with locking-type tamper-resistant refrigerant caps
  • CO detectors are to be installed on all new fossil fuel furnace installations
  • Condensing units and heat pumps are to be installed on a minimum of 3” high pads
  • Programmable set back thermostats are now required

As always, review the most recent local and state codes to make sure your installations are up to date in order to avoid potential code issues. If you have any questions or need assistance, please feel free to contact Famous Supply HVAC Technical Support.

Jeff Rosenblum 
Technical Support Manager 
14 Years Industry Experience
Cell (330) 962-2491
jrosenblum@famous-supply.com

How to Test a Pressure Switch

To test a pressure switch you must first have a compound pressure gauge (digital or analog).

Tee in a plastic tee for both the positive and negative ports for the pressure gauge, start unit up and observe the reading on the gauge. The reading must be higher than the setting listed on the pressure switch. If the pressure switch only has 1 port then tee in the correct port of the pressure gauge and leave the other port open to atmospheric pressure.

If the reading on the gauge is lower than that of the switch then the problem is in the furnace or venting.

If the reading on the gauge is higher than that of the switch and the switch is not closing, then the problem is the switch.

Jeff Rosenblum
Technical Support
14 Years Industry Experience
Cell (330) 962-2491
jrosenblum@famous-supply.com

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