Heat Pump

[Deltarat]

I am going to replace our heat and air in 2400 square foot house. We live in Ms. so we have heat and humidity. What are the advantages and disadvantages of a heat pump?
Are variable or 2 speed air handlers worth the money?
What about 2 stage compressors?
I trying to learn as much as I can before I start getting prices.

 

[Dick in Wisconsin]

Do you have access to a well with lots of water? A way to get ride of the water? Consider a ground water heat pump aka geothermal.

http://www.waterfurnace.com/

 

[pattenp]

I got a new heatpump with a variable or 2 speed air handler. And now I have what is called dirty sock syndrome. I've been told the 2 speed fan contributes to it because of the lower fan speed does not completely dry out the coils which then causes a slime to grow.

Read these.... http://blog.foxservice.com/bid/217398/Dirty-Sock-Syndrome-What-Is-It
http://homeenergypros.lbl.gov/forum...high-efficiency-hvac-units?xg_source=activity

 

[pop pop]

Patten, your fan should continue after the comp cycle to dry the coil. I'd look into this problem. It isn't necessarily the low speed causing the dirty sock. Low speed will dehumidify if you have the humidistat control. I love my Carrier variable speed air handler with humidity control and two level gas furnace back up heat pump. Always comfortable and low cost operation.

 

[Milton Shaw]

The major advantage of a heat pump is in the fact that they can create 3 times the BTU's from the electrical current they use over an electric furnace. For instance 1kw of electric heat produces 1352 BTU's where a heat pump can create three times that or over 4,000 BTU's heat. Some are more efficient and some are less but that is the general guideline of what the savings can be. They would also be air conditioners in the summer. If your normal outside winter temp is below 30 then heat pumps loose there advantage as the heat to extract from outside is going to take a lot more energy to do so, this is where the water/ground source heat pumps have an advantage. Two speed compressors and two speed blowers are also money savers as the drop to a lower energy use as the demands drop from peak loads.

 

[theoldwizard1]

What is your lowest winter temp ? I would guess that modern heat pumps would NOT require any resistance heat in MS.

Do any of the HVAC manufacturers make inverter central heat pumps ? Their big advantage is they have infinitely variable speeds (not the fan, the pump it self).

 

[pattenp]

I have a Trane and all I can say is this is what I've been told by the company that installed the heatpump and a Trane rep. Trane now has a coil with a special coating to help prevent the bacteria growth. Nothing has ever been mentioned about a humidity control for the unit. When the unit cuts off, the air handler fan does run at a very slow speed for sometime afterwards but I still get a funky smell every once in a while.

Patten, your fan should continue after the comp cycle to dry the coil. I'd look into this problem. It isn't necessarily the low speed causing the dirty sock. Low speed will dehumidify if you have the humidistat control. I love my Carrier variable speed air handler with humidity control and two level gas furnace back up heat pump. Always comfortable and low cost operation.

 

[Centex Hokie]

Advice on heat pumps

I have two (2) Heat pumps. One is a Lennox unit that at the time was the 3rd highest rating and the other is a Trane unit that was the best unit at the time a XL20i. The Lennox unit has been flawless for 4 years while the Trane unit which cost more has been unreliable.

I have an engineer who works for me that was with Trane for 7 years. He says that the problem is not Trane versus Lennox, but the fact that the top of the line units have to have all of the tricks to maximize the efficiency and thus are at the edge of the available technology. I tend to think he is correct based on the 4 failures that we have had on the Trane unit in less than 2 years. Most of them have been to the electronic controls. No matter what unit you choose you might want to step back a model or two (2) from the top.

 

[JakeKohl]

I got a new heatpump with a variable or 2 speed air handler. And now I have what is called dirty sock syndrome. I've been told the 2 speed fan contributes to it because of the lower fan speed does not completely dry out the coils which then causes a slime to grow.

Read these.... http://blog.foxservice.com/bid/217398/Dirty-Sock-Syndrome-What-Is-It
http://homeenergypros.lbl.gov/forum...high-efficiency-hvac-units?xg_source=activity

I've been through this and heard every stupid excuse in the book. Brand new heat pump...dirty sock syndrome. Old heat pump didn't do it at all. I'm convinced that higher temperature cycles between operation and defrost modes triggered some sort of organic growth to outgas. I've heard about UV sterilization (some of which destroyed the coils) and other gimmicks but no really good solutions.

I went about this scientifically and couldn't come up with much. There are particular products designed to clean the coils (with some sterilization aspects) that would fend it off for a while. I had one technician spray it down with Lysol and that did just as well (if not better...although I have no idea if there are any ill affects that could cause corrosion of the coil?). Even removing the filter and spraying Lysol into the running intake helped (avoids climbing into the attic and taking stuff apart).

A couple of years ago, I had to put down my Pit/Boxer who was an inside dog (and a terrific dog), and the problem almost went completely away... We still get a whiff of it every now and then and suspect that it's the old ducts that are still supporting the bio-whatever that was leading to that smell.

 

[brewchief]

Do any of the HVAC manufacturers make inverter central heat pumps ? Their big advantage is they have infinitely variable speeds (not the fan, the pump it self).

Lennox now has one, XP25, others may have them as well.

The majority of equipment we install has either a constant torque or variable speed indoor blower motor, we do some multi speed heat pumps and A/Cs but we don't have enough hours using A/C per year to make it a real money saver for most of our customers.

 

[pop pop]

I have a Trane and all I can say is this is what I've been told by the company that installed the heatpump and a Trane rep. Trane now has a coil with a special coating to help prevent the bacteria growth. Nothing has ever been mentioned about a humidity control for the unit. When the unit cuts off, the air handler fan does run at a very slow speed for sometime afterwards but I still get a funky smell every once in a while.

Suggest you have your fan timed to run a bit longer. Also check out if you can adapt to humidity control with the humidistat.

 

[Deltarat]

If it helps, we have 4 months in the high 90s to 100s. Our winters some 20s at night to 40s during days.
I am all electric, but am going NG heat either back up to the heat pump,if I go that route or for full heat if no heat pump.
I have a 4 ton, but it doesn't keep up in the summer, so I am going 5 ton to replace.

 

[Ohmthis]

Deltarat, if you are going with NG then I would just go with a high efficient furnace and straight AC. Electric would have to be really cheap for you to do a heatpump and gas backup.

 

[bazar01]

Look at zoning your 2400 sqft house into 2 zones instead of installing just one 5-ton unit.

I used to have a 3.5 ton whole house split type heat pump with electric back up heat. Having just one unit to heat and cool the house is not very practical and with 3 children already out of the house made it even more inefficient.
I installed a separate 2 ton split unit for the bedrooms with supply and return ducts and left the 3.5 ton to heat and cool the open spaces. My electric bill has dropped a lot after I did that.
When time comes, I will replace the 10 SEER 3.5 ton unit with a 2 ton high efficiency.

 

[sevenzeronova]

I would use multi head inverter driven condenser. Only going cool or heat what's needed.

https://www.google.com/url?sa=t&sou...de2TfRBCCFRd8XKnw&sig2=TTDJgsHvARJVcGTOkyb1og

Sent from my SM-N900V using Tapatalk

 

[pop pop]

If it helps, we have 4 months in the high 90s to 100s. Our winters some 20s at night to 40s during days.
I am all electric, but am going NG heat either back up to the heat pump,if I go that route or for full heat if no heat pump.
I have a 4 ton, but it doesn't keep up in the summer, so I am going 5 ton to replace.

If you have gas available, consider the dual fuel heat pumps - summer AC w/ humidity control (especially nice where you live), heat pump down to about 35- 40, then gas to keep you warm when it's really nasty. You may not need a large gas furnace there, I have two stages here in Va and rarely use the second stage till we hit single digits. With the humidity control you an lower the inside hum. in summer and keep the sensible temp much higher. We set for 78 inside summer and 50% hum. and you will often get chills! With good installation/setup, I don't see "dirty sock" happening.

 

[Deltarat]

What utility saving could I see using a heat pump with gas back up as compared to conventional AC and gas furnace?

 

[AP514]

Im here in Houston and have an American Standard and has a NGas heater for those colder days. I have a 3-Ton (18seer) and 2-Ton(16Seer) for my 3K SF single story house.

My suggestion would be to get the HIGHEST SEER Rating you can afford..it will pay off in the long run...

And on a side note for the DIRTY SOCK poster...
I had a little trouble with my old house...
1) Up'd the run time after the Compressor kicked off and it helped....
2) but found that my unit in attic had settled a bit and water was being trapped/staying in drain pan area of condenser unit.
2 toilet(Shimming material) wedges under the unit(to tilt more to drain side) Fixed me right up..No MORE SMELL

 

[theoldwizard1]

What utility saving could I see using a heat pump with gas back up as compared to conventional AC and gas furnace?

Hard to say. The operating costs would probably be pretty close.


If you don't have natural gas already, I would stay away from it just because of the initial cost. However, if you are planning on switching your hot water, clothes drying and cooking over, that is a different situation. Then go for the forced air.

 

[HAP]

Easy solution that works is installing a UV light in the coil area. They make various sizes to fit your coil.

R,
HAP

 

[Deltarat]

Hard to say. The operating costs would probably be pretty close.


If you don't have natural gas already, I would stay away from it just because of the initial cost. However, if you are planning on switching your hot water, clothes drying and cooking over, that is a different situation. Then go for the forced air.

I already have gas for a radiant heater in the den and gas for my shop heat. I am all electric,but will replace one of my electric water heaters with gas one day in case of power outage.

 

[theoldwizard1]

I already have gas ...

Gas force air and A/C will have the lowest installation cost. Spend extra for the highest SEER A/C. Check into upgrading your insulation.

The lowest operational would be a ground water heat pump (aka geothermal) like **** in Wisconsin said. Expensive to install, but VERY economical month to month especially in the middle of a heat wave !