Where Good Neighbors and Good Servicemen Meet

The Heat Pump

The heat pump is merely an air conditioner with a reversing valve, check valves, and a defrost mechanism. The outdoor compressor runs in the summer to cool and in the winter to heat.

The Short Story

Let me contrast a heat pump with a regular AC using electric strip heat. A heat pump will save you 50% in the heating mode, but it will lose 10% when cooling. For the Brazos Valley, what you lose in the summer will not be recovered in the winter.

Numerous AC researchers and managers of utilities—with the exception of one man—have agreed in their conversations with me: A heat pump, in our community, is not cost effective. There is no utility savings, and it can be very expensive to repair.

The Entire Story

The utility companies push heat pumps because they want to balance the load on their generators, but there is absolutely no other justification for a heat pump in our community. The homeowner has nothing to gain and everything to lose. My 24 years experience says avoid heat pumps like the plague.

If you already have a heat pump, the details that follow will help you manage your comfort system, and prepare you to deal with the next replacement situation. It's easy to convert a heat pump to a conventional air conditioner. Just replace the condenser and the thermostat. The air handler, ductwork, wiring, and copper tubing can remain in place.

This article goes on and on, for those who have the time to read this stuff. The sheer length of explanation that is required, adds weight to my claim: heat pumps are bad news.

Explanations

When the unit goes into the defrost mode, the compressor will continue running, but the fan will stop, and the homeowner will see steam coming from his outdoor unit. This may seem strange, but for a heat pump it's normal. Indoors, the blower will continue to run for the duration of the defrost cycle.

In the heating mode, your primary source of heat is the compressor in reverse cycle. Your secondary source of heat is the back-up heat strips. If the compressor fails to maintain the desired temperature, the back-up strips will automatically kick in.

Some people like to go to the thermostat, and lower the temperature before they go to bed. In the morning they raise it. With a heat pump that's not a good idea. It causes the heat strips to come in, and defeats the purpose for which the heat pump was designed.

Set your thermostat to a temperature, and leave it there. If you use a programmable thermostat it should have intelligent memory so recovery will be gradual. The cheap on/off thermostats will bring in the heat strips during recovery.

Don't even think of buying a heat pump thermostat for self-installation. Heat pumps are complicated, and every brand is wired differently. Leave thermostat selection and installation to the professional.

Cautions

In the presence of ice or snow, accumulation on the fan blades can cause serious problems. One should go to his thermostat, and move the selector to the "Emergency Heat" position. That will disengage the outdoor unit from the system, and activate the back-up heat strips.

Application

There are several objections to the heat pump, but in the right climate, it might be okay. The air from a heat pump is not nearly so toasty as from the other three heat sources, but the problem can be easily fixed.

Most registers (vents) are in the ceiling, and usually are of the stamped face design. That allows the air to blow directly onto the occupants. Replace the registers with ones that are of the curved blade design, and the problem is solved.

Electric Utility Companies Love Heat Pumps

Heat pumps are being widely promoted by utility companies. They want to balance the load on their generators. I cool my home with electricity, and heat with gas. They would prefer that I have a heat pump, which would increase my usage of electricity in the winter.

Now for the other half of the story: Our climate is very mild, so electric resistance heat is popular—especially for rental units. That presents a different problem for the utility company. Resistance heat, on the average, takes twice as much electricity as a heat pump, and that creates a demand spike.

Added to that, ours is a student community, and the usage becomes greater when the students are in town, and less when they leave for holidays. Again the utility company prefers heat pumps.

Often the utility is owned by the municipality. Some cities have ordinances that apply to new construction. In the absence of natural gas, they require heat pumps.

From the Homeowner's Perspective

A heat pump using traditional R-22 refrigerant should never be installed in a climate where temperatures are consistently below freezing—for example, in Michigan. R-22 heat pumps lose their effectiveness below 37F degrees. Newer heat pumps that use R-410a refrigerant work to 0F degrees and can be used further north.

My brother lives in Southwestern Kentucky. Heating demands overshadow cooling needs, but temperatures are still relatively mild. In the absence of natural gas, the heat pump might be his best option.

For most people in Texas, the heat pump is a really bad choice. There's a 50 percent utility savings in the winter, but during the summer, we suffer a 10 percent loss. Most people in Texas do little heating, so what they lose in the summer will never be regained in the winter.

People who play around with their thermostat during the winter, get the worst of both worlds. They lose 10% efficiency in the summer, and they also lose in the winter—every time the heat strips are unintentionally activated.

We live in the Brazos Valley. Most people who install heat pumps (instead of resistance heat) think they will save money. They actually lose money.

Why Choose a Heat Pump?

Why should anyone in our community install something that is tricky to use, will increase utility costs, is expensive to repair, and can cause lots of problems? For us the heat pump is a gross misapplication.

Once every 20 years we have a prolonged cold spell, and people who have resistance heat can encounter a really big monthly electric bill. My advice is to keep a couple of safe space heaters in your closet. Every 20 years use them to zone heat certain rooms.

Theoretically, the break-even line is drawn East to West through Sherman, Texas, which is about 80 miles north of Dallas. I have run my story past a number of researchers, and each has agreed with me. One man looked at me and smiled, "And they use them in the Valley" (Brownsville area), he said.

Heat Pump Repair Costs

Compared to a conventional air conditioner, a heat pump can be a diagnostic nightmare, and repairs can cost you big bucks. A reversing valve replacement might cost you $500 or more, and a regular air conditioner doesn't have one. I will illustrate using five actual case histories from our community.

Here's what Harry had to say: "Originally, I had resistance heat. It was replaced with a heat pump, and the guy said I would save money. I didn't save on utilities, and I have had nothing but trouble."

It was time for another replacement, and he wanted resistance heat.

Jesse's heat pump would keep running even after the thermostat was satisfied—it would freeze up. He had tried two repairmen, but neither had been able to make the repair. My name was given to Jesse as someone who is persistent. I made two trips, but the problem continued. I called my service tech. During the discussion I asked whether it might be the defrost board. (Regular air conditioners don't have a defrost board.) My tech said, "No." Then he looked at the wiring diagram, and said, "Yes it could be." I replaced the board and the problem was fixed.

Jessica complained that in the AC mode her heat pump was not cooling properly. First we found freon leaks in the evaporator coil, so we replaced it. But the problem continued. We spent four hours trouble shooting and making phone calls. It turned out the back-up heat strips were coming on along with the AC compressor, and the heat was fighting the kool. Because this was a heat pump, we wasted lots of time running tests that would not have been necessary if it had been a regular air conditioner.

Andrew had a problem that was finally traced to the defrost timer, but nearly sent three air conditioning repairmen to mental rehab. It just wouldn't misbehave when the serviceman was there. ABC company made two trips, and replaced the fan motor. I was then called in—I made eleven trips. When I was unable to solve the problem, I turned it over to XYZ company, and he made two trips. Fifteen trips, and the problem was solved.

Mary Jane's heat pump would work in the cooling mode, but when she called for heat, it would trip the high pressure switch. My company installed the system, and it was still under warranty. Under the guidance of my tech service rep, I went to work. We ran a myriad of tests, and tried first one thing and then another. Each trial took 2-4 hours, and we went through several iterations. We adjusted the refrigerant charge, added an air distribution duct, and then changed suspicious components. We replaced:

• The indoor expansion valve.
• Then the evaporator coil.
• And then the blower motor.

Nothing worked. I ran some final tests, and then called for help. My tech service rep came from Houston, and found the problem. The air handler I chose for the original installation is okay for an air conditioner, but not for a heat pump. He told me to replace the air handler.

The customer was grateful she didn't have to pay for what could have been an expensive "research" project.

Much Ado About Nothing

The "Mary Jane" example above is a mother-in-law apartment, an add-on to an existing home. It's too small for a gas furnace, so we had to go with electric heat. The logical installation would have been a conventional AC unit with a single heat strip. But because of a city ordinance, we had to install a heat pump. The extensive work described above was totally unnecessary—a good example of what happens when government meddles with free enterprise.

Some Heat Pump Installations Actually Work

I've given five examples of what I call Heat Pump Trauma. But not everyone who owns a heat pump will have trouble. Some people go 20 years with nothing more than routine service and minor repairs.

A Misapplication

Trouble shooting heat pump problems is like looking for a needle in a haystack. Once you find the problem, you wonder why it took so long. Repairmen in colder climates, like that of Kentucky, are probably quicker when it comes to diagnostics because they have more experience. And in their climate it might be worth the effort. But for our Texas locale it's, as I said, a misapplication.

It's Not Your Problem

If heat pumps are a misapplication in this area—and they are—then the utility companies should find another way to balance their generators.

A Pain in the Lower Torso

At first I found heat pumps to be a pain in the neck. With time, the pain has moved lower. No matter what part of the country I ever call home, I won't, under any circumstances, install a heat pump in my house. I'll find another way.

It Would Seem

Most people use electricity to kool their home—demand in the summer is huge. In the winter there is no AC load, and many people use natural gas to heat. Can't the same generators that made electricity for kooling now make electricity for heating?

Fact or Theory?

The unstated rationale for heat pumps is that they will balance the load on utility company generators. But does the theory translate into fact? In the presence of ice or freezing temperatures, the prudent thing is to move your thermostat from heat to emergency heat. That shuts off the condenser, and you are running 100% on heat strips. That results in a giant power spike, which is what the heat pump was designed to avoid.

Under the worst possible heating conditions, the utility company is faced with a maximum power requirement. At that point they need full generator capacity. So why a heat pump in the first place?

Heat Pump Ordinances

Heat pump requirements are especially upsetting to me because, for the Brazos Valley, it's not in the best interest of the homeowner.

It bothers me that utilities, municipalities, and contractors are misleading people into believing the heat pump will save them money. (And I suspect for all their misplaced efforts, the ultimate benefit to their generators is zero.)

It also bothers me that the government would presume to make choices that rightfully belong to the individual.

A Most Unkool Situation,

Dr. Kool

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