Heatpumps

Hvactech58

Hey Professor, Since we're closing out the summer and are going to be getting ready for winter, how about sharing some helpful hints on the equipment we all hold dear to our hearts? The Heatpump!!!

Eugene Silberstein 3

Perfect Time

Here in the Northeast, it's the perfect time to startup those heat pump systems to be sure that they will operate as desired once the colder months come around.

Here are a few tidbits:

If the heat pump system is operating properly in the cooling mode (proper refrigerant charge), the system IS PROPERLY CHARGED IN THE HEATING MODE.

If the system operates properly in one mode and not the other, the problem is not the refrigerant charge.

If the system fails to operate in both the heating and cooling modes, eliminate those components that are only in the active refrigerant circuit in one mode. For example, the expansion valve a the indoor coil is most likely NPOT the problem, as it is only in the active refrigeration circuit in the cooling mode.

Get it?

As with any other system, look for the obvious first. Defective fan motors or blower motor, for example.

When starting up the heat pump system in the heating mode, always check the defrost cycle to be sure that, once ice starts to form on the outdoor coil, the system will be able to remove it efficiently.

For more on this absolutely wonderful topic, check out:

http://www.heatinghelp.com/shopcart/product.cfm?category=2-103

Thanks for the post HVACTECH58.

soot_seeker_2

winter lumes near.......


ready, get set, fire up your crankcase heaters!

actually, i've seen it stated that crankcase heaters are more important for the very hot weather. yet i've also read a few manufacturer's installation docs that claim it saves the compressor (from refrigerant/oil mix) in cold weather. i've also seen some 'brilliant' hvac guys that solve that question by simply cutting them out of the system (suspecting intermittant shorts) or removing them completely after a compressor change-out. i'm mainly talking about the 'belly-band /wrap-around' style rather than the trane insertion style design.

maybe this will generate a bit of discussion about these here.

ss

don_156

Hey

what with you guys, are you too busy?It sure getting boring around here.

Ok I'll try to get it going.

Why is it when people have heatpumps that they never realize they have a problem with the outdoor unit unless they keep track of their electric bill..or untill summer
arrives?

And why do people whom buys a home and experience a heatpump for the first time,seen to always call in the winter saying that the heatpump is on fire?

soot_seeker_4

- good questions -

i guess the hydronic heating season experience is just more exciting than the a/c - heatpump stuff. people seem to be much more concerned with efficiencies when they're burning ng or oil rather than just running up the electric meter. had another screaming tigerloop yesterday - you just don't get to see those on the a/c side.


1. the 1st one is because the compressor function is out & the emergency heat coil is being used & they just don't grasp what that means until they get the electric bill much later with new balanced budget accounting.

2. the 2nd one is because they've never noticed their defrost control in action in the middle of the winter - freaks them out.

i'd still like to see my crankcase heater discussion addressed above.


ss

don_158

I'm

sorry soot.I guess there not much to talk about being you've already anwser your own question.

I like you was always told it was to evaporate the liquid
refrigerant trapped in the oil.

As for ease of replacement..I prefer the bellyband over the insertion type.

Eugene Silberstein 3

A few more tidbits

Quite often, people don't realize that their heat pumps are not operating efficiently, as long as the second stage (or supplementary) heating mode is operational and able to handle the load on the structure. In most areas, electricity is very expensive and, the astute homeowner will notice the sudden increase in energy usage when the electric strip heaters are energized most of the time.

One tell-tale sign that the heat pump system is not operating properly in the heating mode is the absence of ice or the lack of system defrost. Although the amount of ice on the outdoor coil will be very low in climates that have very low humidity levels, there should be at least a frosting on the coil surface.

Those who have had heat pump systems, or a single heat pump system, are more likely to notice problems with their system a lot quicker than those who are not used to having them around. For instance, if the outdoot coil stops icing up as it has in the past, the homeowner will likely call the service company with a JDLR situation (just doesn't look right) and have it checked out.

Those individuals who are new to the "heat pump way of life" are likely to experience a number of new situations. The first being the cool feeling in the heating mode, as the temperature of the air being introduced to the occupied space is lower than with fossil fuel systems. The second being the burning smell that you are referring to. The burning smell is a result of burning dirt particles that have accumulated on the surface of the electric strip heaters.

During the cooling months, a certain amount of dust flows through the duct system and gets caught on the electric strip heaters. When the sytem is put into the heating mode and the electric strip heaters come on, the dust burns off and the smell of "the sytem being on fire" becomes evident. In addition, when the system goes into defrost, the melting ice and the vaporizing liquid can definitely scare the unsuspecting homeowner.

As far as it getting boring in here.... I must apologize as the school year has just started and I am still getting my classes and students set up for an awesome semester.

Hope this Heat Pump 411 was useful.

don_156

No

need for apology Professor..I was just trying to fire up
some of the fellas.

We all have to feed the family. Best regards!