A/C or Heat Pump

[David A. Andersen]

I personally think that cost and homeowners wants will prevent getting the idea numbers. Is that person going to design a house or use the right components resulting in proper static pressure and velocity pressure = friction loss? I doubt it.

Not to prolong this subject; but determining friction loss design takes about 10 min!

How much is that going to cost the owner?

Using the right "component" Saves Money. Duct costs are determined by the pound (or kilo for those up north). The reducer to maintain correct friction loss design saves money because the duct is only 30" , 5' from the unit.

But then...
Maybe I'm having a senior moment. Flex Duct overcomes all ill design specs...

Just lay it on the ground under the house. They will be replacing it in 7 years anyway!

Is that homeowner going to replace part if not all the duct when the new furnace is replacing that 40 year old one. I doubt it.

They won't have to if it was designed right to start with...

Oh Hell, there I go with my glass half-full again!

[kluce]

Originally Posted by dandersen

Oh Hell, there I go with my glass half-full again!

[Joe Funderburk, CMI]

Originally Posted by dandersen

Running in heat may not energize the outdoor unit (there is no condenser on a heat pump).

Please explain "no condenser".

http://en.wikipedia.org/wiki/Heat_pump

[David A. Andersen]

A heat pump coil (regardless of where it is located) becomes an evaporator and/or condenser at some point.

If you guys want to test what you have no obligation to test, at least get the reporting terminology right.

There is no evaporator or condenser in a heat pump system.

Though it may see simplistic, they are "indoor" and "outdoor" coils.

[Wayne B. Wilson]

Yep true David

[Joe Funderburk, CMI]

Originally Posted by dandersen

A heat pump coil (regardless of where it is located) becomes an evaporator and/or condenser at some point.

Your sentence above contradicts your sentence below.

Originally Posted by dandersen

There is no evaporator or condenser in a heat pump system.

Wikipedia (an elementary resource, I suppose) certainly references a condenser in a heat pump. What is the thing-a-magig outside the house when the heat pump is running in AC mode?

Not nearly as knowledgeable as you, David, when it comes to HVAC. Not by a long shot. Just trying to learn....but I've never heard it said that a heat pump does not have a condenser.

[kluce]

Originally Posted by jmacdonald

I'm just starting out. Can anyone tell me if there is a sure (easy) way to tell if a heat pump is installed?

Wow, just starting out yet you joined InterNACHI when it was called NACHI in 2003.

Were you thinking about becoming a home inspector for 7 years?

[Bruce M. Graham]

Joe, What David is saying is that both coils act as condensor and evap, depending on mode, which is why in the industry they are refered to as inside and outside coil or section.

[David A. Andersen]

Thank you Bruce (I've been tied up working in the SNOW!).

Joe, It is what they do, not what they are called.
If you call it a condenser, you should indicate in which mode your operating. That works too.

Otherwise it's "Indoor - Outdoor".

This helps greatly in understanding your report, when read by others.
When you talk about a frozen condenser coil (meaning the outdoor coil is frosted because it is operating as an evaporator in the heating mode) it makes your phone ring unnecessarily and makes you look like you don't know what you're talking about. HVAC contractors love to talk down on home inspectors (as do other subcontractors), so don't give them the ammunition for the opportunity.

[rsummers]

No matter how the units are identified Ive always made it a point to comment on the fact that Heat Pumps have a tendency to feel drafty while in operation due to to the fact that the temperature rise is only 20-25 degrees unlike the 30-50 degree rise that you get out of gas heating units. The only way to get high temperatures like that out of a Heat Pump is to have the heat strips on & who wants to pay that bill.

[David A. Andersen]

Originally Posted by rsummers

No matter how the units are identified Ive always made it a point to comment on the fact that Heat Pumps have a tendency to feel drafty while in operation due to to the fact that the temperature rise is only 20-25 degrees unlike the 30-50 degree rise that you get out of gas heating units. The only way to get high temperatures like that out of a Heat Pump is to have the heat strips on & who wants to pay that bill.

Just curious, but how is this associated with the standards of practice of home inspection?

I see nowhere that we are to ensure comfort conditions within the house.

There is a requirement to have the ability to maintain temperature above the floor (nothing more).

Do we really know why heat pumps feel drafty? There are several reasons why.

Heat strips are not the only way to maintain high temperature output.

Maintaining head pressure, maintains temperature output.

If you adjust fan speed control, you can adjust discharge temperature of the supply air. Gas furnaces operate on low speed in heating mode and high speed in the air-conditioning mode. You can do the same thing with a heat pump.

I have a 16-year-old Carrier heat pump that only goes into defrost when there is actually a frost on the outdoor coil (not just because it's really cold outside).

Also, indoor fan speed control changes fan speed in the heat mode if the head pressure falls below a certin balance point.

A proper system design is the primary cause of the "drafty feeling" you get from a heat pump.

They love to blame the heat pump for uncomfortable conditions, but it is just plain bad design.

[rsummers]

Heat pumps feel drafty because the low temperature split typically encountered on properly operating systems with out the back up heat on. Ive replaced many Heat Pumps systems that were functioning properly because they were drafty. I agree that you should not try to determine a systems capacity to condition a home its not in the scope of an Inspection. Heat pump systems fan controls should only altered by a qualified service professional.

[Joe Funderburk, CMI]

Originally Posted by dandersen

Thank you Bruce (I've been tied up working in the SNOW!).

Joe, It is what they do, not what they are called.
If you call it a condenser, you should indicate in which mode your operating. That works too.

Otherwise it's "Indoor - Outdoor".

This helps greatly in understanding your report, when read by others.
When you talk about a frozen condenser coil (meaning the outdoor coil is frosted because it is operating as an evaporator in the heating mode) it makes your phone ring unnecessarily and makes you look like you don't know what you're talking about. HVAC contractors love to talk down on home inspectors (as do other subcontractors), so don't give them the ammunition for the opportunity.

Thanks for the reply, Bruce and David.

[David Moriconi]

Originally Posted by jmacdonald

I'm just starting out. Can anyone tell me if there is a sure (easy) way to tell if a heat pump is installed?

Ever thought about getting some education and training before becoming a home buyer advocate??

[tvargas]

Jim
Also you will see some package units nobody is commenting on . On these
there wont be a flue pipe , heat pumps dont need or have them they operate on
the flow of refrigerent, no gas needed to heat ,just depends on the reversing valve direction.