New Furnace, Heat Pump & Humidifier

[bczoom]

My furnace/heat pump is now 15 years old and the heat pump as been loosing its charge (I need to get re-charged every couple months) so I think I'll replace everything.
The inside furnace is ele. so it's pretty much an aid handler with some strip heat.

My questions are:
Are there any particular name brands that are exceptionally good or bad? I've heard good things about Amana and I believe I can get a good price on one. Trane and Carrier are also reputable brands and I may consider one of these.

Is there a decent algorythm to figure out what size I need? I have a 4+ ton heat pump now and it doesn't seem to keep up (it'll run 20+ hours a day for A/C, probably the same for heat if I wasn't running a wood stove).

I've heard mixed info on a whole-house humidifier that's installed in the plenum. I heard they're great for actually raising the humidity but are very bad for mold/bacteria as it generates a lot in the plenum. Any thoughts/advise?

Thanks
Brian

 

[techman]

The best thing to do is have an HVAC contractor do a heat loss/gain for your house. 4 ton is fairly large, for your locale. An estimate would be 3000 sq ft for a modern construction house for that size. It may have been running so much due to the leak. If the charge is too high or low, the efficiency can drop quite a bit.

As for the humidifier, I would recommend against the disk or drum types. Due to the low duct temps with a heat pump, they do not work very well and are a home for things to grow. The best type for heat pumps utilizes a fine water spray into a plastic chamber that has system air circulated through. The most common ones use an oil burner nozzle, and the nozzle can be changed to suit the airflow, so that there is no excess water. the humidifier helps improve comfort in the winter and preserves things like wood and rugs that can be damaged by the humidity extremes.

paul

 

[bczoom]

Thanks Paul,

It was running almost constantly, even prior prior to the leaks.
The unit was probably sized properly when first installed but I am now running HVAC in areas it probably wasn't initially setup for (basement and other areas that have been finished). I'd have to say the insulation is mediocre in the house.

I haven't physically seen the humidifier unit that's being proposed but as described, it's some sort of unit that has a constant trickle going over it and needs a drain pipe for excess water.

Brian

 

[EastTexFrank]

I don't have any experience with the newer humidifiers but I disconnected the one in our house in Dallas for the reasons you mentioned ... mold. It would grow and plug everything up. It was just 'way too much trouble. Instead I went with a large portable unit that served its purpose but it was a bit of a pain to keep filling it up every day, when in use.

Whoever you decide to use for installation should be able to size the unit properly and all the brands you mention are reputable. I don't know if any one is better than the other. It may be a bit like tractors, your dealer/installer may be the most important choice you make.

 

[thcri]

Get a new complete heat loss/gain from a local HVAC Contractor. If you have added to your house you need to have that done. As far as the brands you listed they are all good. My company handles Carrier and for the most part they have been pretty good. Trane is about the only manufacture that still makes it own compressor and it is a tough one. As far as the air conditioner running constantly that is pretty much normal. Remember we use the air conditioner to remove humidity in the summer also, not just for cooling. If the air conditioner shuts down then the humidity will start going back up. As far as the humidifier most electric applications don't need a humidifier like forced air furnaces that took air from your house for products of combustion. We sill recomend the bypass humidifiers that April Air or Carrier makes. If you don't think they will perform enough with the cool plenum air then hook it to your hot water line. We do that all the time when one doesn't keep up.

murph

 

[Inspector507]

Here's a calculator on the web, takes some prep work to use. Measure each room including windows and doors first though.
SpacePak

 

[kenmac]

You didn't say how many sq. ft. your house is. 15 yrs. on a heat pump is good some go out sooner considering that the compressor pulls double duty (runs winter& summer)If you have around 3000 sq. home a 4 ton unit should do the job.You may have an A coil leak. I have been running across alot of A coils that are leaking thats only a couple of years old. Or you may have just the best of yours at 15 yrs old. wouldn't hurt to have it checked, may run another 10 yrs.Every contractor will have a different opinion on units. Trane/ American Standard as Murph said is the only company that makes their own compressors & in my opinion are the best followed by copeland.I install humidifers on gas furnaces but hardly ever on elec. units.

 

[bczoom]

</font><font color="blue" class="small">( As far as the humidifier most electric applications don't need a humidifier like forced air furnaces that took air from your house for products of combustion. We sill recomend the bypass humidifiers that April Air or Carrier makes. If you don't think they will perform enough with the cool plenum air then hook it to your hot water line. We do that all the time when one doesn't keep up. )</font>

Murph,

I run a wood stove 24/7 for about 5 months during the winter.
We're using stand-alone units now but like EastTexFrank noted, they're a bit of a pain.

I pulled up the one that Carrier makes. Aren't these like the "whole house" humidifiers that can generate mold? Are you saying that if I pump hot water through it that it will evaporate better and not collect mold?

Brian

 

[bczoom]

Thanks Inspector for the link (and everyone else that said to get a loss/gain).

I ran through the link with general numbers and it came up with this:
Total Residence Heat Loss: 127788.21
Total Residence Heat Gain: 15093.39
Model Number Recommended: ESP-2430D (2 Ton)

It spit out a 2 ton unit which surprized me so I think I'll have a pro do it. The area is about 3400 sq/ft and about 30,000 cu/ft but with cathedral ceilings, lots of windows, wood burning stove... too many variables and I don't want to guess.

 

[bczoom]

On a side note:
The inside air handler and heat pump both got new ele. motors (and fan blades on the outside) about a year or 2 ago.
Being nice (proprietary size by Lennox) motors, I paid dearly for them.

Can I re-use them in other applications?

I was thinking of mounting the heat pump motor and fan horizontally and using as a "through the wall fan" in my building workshop.

For the motor inside the furnace, I was thinking of casing it in and making into a floor type fan (to blow air across the floor for drying).

Can I do this? (If so, I'll then ask for wiring instructions /forums/images/graemlins/crazy.gif)
Brian