Ptac stands for Packaged Terminal Air Conditionerptac-bedroom

Everyone has experienced the comfort of an air conditioned hotel room. The ptac is the go to choice for small rooms in need of zone controls. Each room is automatically its own zone so that the entire building does not have to be air conditioned but if every room is occupied, the entire building can be cooled or heated. Also individual zones can have their own setpoint.  Modern units are quiet and versatile.

The problem with working on ptacs is that they are so diverse.  Their needs to be a universal control box that can be understood by both HVAC and appliance technicians.  I recently worked at a hotel that had approximately 20 extra units in a make shift work area.  I came up with a semi-universal component arrangement that can be understood by any good handyman, Read the rest of this entry »

caveman_fire  Burning fossil fuels to heat our homes and buildings needs to go away.  More people have become aware that heat pumps can move heat from the outside to the inside in the same way that air conditioning does, only in reverse.  In fact, a heat pump is exactly that: An air conditioner that is capable of reversing the flow of heat.  Heat pumps are powered with electricity and electricity can be generated with very little carbon emissions and environmental impact and transmitted directly to the end user.  Almost all alternative energies find their end use in the form of electricity.

The question arises: Why would anyone have an air conditioner that is not capable of reversing the flow of heat? Or perhaps, have a solar powered air conditioner and continue to burn fossil fuels for heat when the very same air conditioner could supply most of the heating requirement. Unfortunately it was not a well informed decision. Tragically, when a home is built on a natural gas distribution line, not only will a furnace be the norm, it will be replaced like for like for the life of the home. This in spite of the fact that a furnace becomes increasing more dangerous as it reaches the end of its useful life and requires a humidifier to keep from drying out peoples skin. Many of the homes in the south that have a furnace are also poorly insulated with low efficiency windows simply because it is gas heat.

Why then, is the already built home the greenest of them all? Mostly because of the potential in energy savings compared to expenditure of demolition and reconstruction. I believe that more emphasis should be place on reaching that potential with heat pumps and envelope improvements in the already built community. A good stewardship model for making buildings more green would be to tighten the envelope and improve the insulation to the point where a heat pump can carry the heating load with little assistance from auxiliary heat from resistance coils or burning fossil fuels. The cost effective way is to incorporate solar or wind as an alternative or auxiliary energy source.

Many modern construction projects follow this thinking and project these savings into the future and that is wonderful. Geothermal and mini-split heat pump systems are far and away improvements over past building designs. The savings can eventually rationalize the additional expense and even recapture some of the interest. There are also projects to green already built communities and to finance the endeavor with the saving on utility bills. Investments to pay it forward that reap rewards in carbon equivalent reductions.

It is still very rare to see a home with a furnace that is replaced with a heat pump.  A contractor isn’t going to go to the added effort and cost of running an additional large amperage circuit that is required for the back-up heat. He would be hard pressed to ignore the gas line on a package unit to install a heat pump unless it was an expensive hybrid package unit with a fancy thermostat. The homeowner was caught off guard by the failure of the furnace on the coldest day of winter so far and doesn’t have the capital on hand to invest in a higher SEER unit.

What if the trend for heating with fossil fuels was reversible? What if the air conditioner in an existing furnace could be upgraded in the field? I may not be the first to ask this question. Heat pumps actually predate modern air conditioning. It would be nice if someone had advocated the benefits of heat pumps all along. The fact is that the fossil fuel industry has done a good job in negative campaigns designed to keep down the competition from heat pumps. I can’t recall a single instance of an electric provider defending heat pumps. They have become more dependable, more efficient and quieter while package furnaces are still only 80 % efficient.

I have been upgrading air conditioners for over ten years. I can take a gas pack that is nearing the end of its useful life and extend that life for another ten years. I can turn it into a hybrid heat pump with environmentally friendly refrigerant that runs on less electricity and 90 % less fossil fuel. I have overcome most of the obstacles that an HVAC service provider might run into when offered the opportunity to retrofit an existing unit.

I have offered the power of choice to many customers and delivered on my promise of green comfort, dependability , and efficiency.  My last and greatest challenge is to change the hearts of people away from the heat of burning fossil fuels, to the warmth of hybrid heat pumps. If you already have a heat pump, may God continue to bless you! If you have an air conditioner that was not a heat pump from the factory,  now is the time to reverse a poor decision. Whatever means of heat you choose , make an informed decision.  Now that you know that a heat pump can be upgraded from an ordinary air conditioner, help me reverse the outdated and unnecessary practice of  burning fossil fuels to heat homes and buildings. Even if someone long ago made a poorly informed decision, it’s in your power to make the choice.

shapeimage_1This is an old mechanical thermostat with mercury in the switches. I am using it in this illustration because one can clearly see the switches. Here they are again blown up.select-mechanical-thermostat The good thing about this old style thermostat is the lights on the bottom row above the word weathertron. Here is a direct quote (edited)from the site where I borrowed this picture.aux heat This description is of a typical heat pump with electric back -up. A hybrid heat pump has natural gas or propane back-up. This description should point out the superior abilities of hybrid heat pumps. The back-up heat is hotter when you need it most.

AUX HEAT means auxiliary heat and EM HEAT is emergency heat, sometimes also abbreviated as EMERG HEAT. Both settings turn on an electric resistance heat strip in a heat pump air handler, which is similar to the heating element in a toaster oven, but they activate it in two different ways.
To understand why an electric resistance heat strip is needed, it’s necessary to review how a heat pump works. It does not actually create heat but, instead, absorbs heat from one location and moves it to another. During the summer it absorbs heat inside your home and moves it outside, with a reverse in the direction of heat transfer happening in the winter and heat moving from the outside to the inside. When the outdoor temperature gets close to freezing, it becomes difficult for a heat pump to efficiently absorb heat outside to transfer into the home.

There are several reasons why a heat pump will bring on the aux heat.

  • If the heat pump needs assistance to maintain the indoor temperature
  • because the thermostat has been set more than 2 degrees above the current room temperature
  • because it is unable to maintain the thermostat setting with the heat pump alone and is falling behind—it automatically switches on the electric resistance heat strip to produce additional heat.

In programmable thermostats , the term setback is used to denote a lower temperature setting in order to save money. Heat pumps need to recover from setbacks without using the aux heat in order to insure savings. Otherwise, whatever savings have been incurred by the setback will be quickly offset by the aux heat. Typically, a small light turns on next to the words AUX HEAT on an older thermostat like the one above, or AUX HEAT appears on the screen of a new digital thermostat.

tstat imag emergency heat (640x426)

Heat Pump Thermostat

Some thermostats have the ability to know the outdoor temperature. This is a tremendous advantage because it can switch to emergency heat automatically. If your thermostat does not have this ability and you have a typical heat pump with electric back-up; then you may want to know when you should put the heat pump on the emergency heat setting. Here is the most concise way that I can word it.

If the forecast high is to be in the twenties, use emergency heat.

If the low is going to be in the twenties, let the heat pump eat.

Your heat pump is a beast in mild weather. Let it do its duty. It can absorb as much heat from the outside air as it does from the inside air in the cooling mode.

Air QualityIn the HVAC industry, we are entrusted with guarding the air quality of our clients and customers. One of the definitions of air conditioning is to filter the inside air and the choices we make in heating our homes have a major impact on the quality of outside air. Read the rest of this entry »

Even though the Tennessee Valley Authority has harnessed the Tennessee River to provide inexpensive electrical power and flood control to the region where I live and work, there is still a large network of Natural Gas development.post-hp2

The Water Cycle
The definition of refrigeration as it is applied to a heat pump is to absorb heat and release it into where it is needed. In the illustrations, one can see how the water cycle is a natural comparison. 96 % of the renewable energy in the United States is hydroelectric. These two cycles can be used to produce all of the power, heat and water that we need to live with a very small carbon footprint.

enclosure8I have chosen a new electrical enclosure for the second generation control box. It’s design is intended to make the total package more attractive and bring down the cost as we move from prototype to production phase. The plan is to sell 100 units to the area in and surrounding Chickamauga Georgia for the 2014-2015 season.IMG_20140801_103811757The original control box is shown in profile from an early prototype. It has served well and the customer is going through her old bills to see how much she has saved in the past six years. The new design will be mountable on top of the unit. IMG_20140801_103848955Here is a picture of the prototype control box with the cover off. It is able to control the dual fuel with a circuit board and reset button and analog relay. The new design will be for use with a new thermostat with optional wireless controls or a Bill Porter outdoor thermostat.

Financing available from PayPal

Changing the fluid (freon)in your air conditioning unit  is a good alternative to changing the equipment.  $240 is the average charge for the new refrigerant Dupont 407C. This includes the labor and recovery fee to dispose of the newly banned R22 that is in most sytems built in the last 5 years. An older system that has been retrofitted to R407C is at least as good or better than a new unit with R410 A.

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