Time To Replace Some Heat Pumps-Or At Least One

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dibbons

dibbons

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Rental home of 4000 square feet (two story) in climate zone 3 in California has the original heating/cooling system installed when new in 1979. Tenants are paying $1,000.00 in electric bill monthly, so time to upgrade the system is long overdue. Summer days often hit 100 degrees and it can get chilly during the winter.

There must be 50 brands/sub-brands of heat pumps/air handlers out there, pretty overwhelming trying to decide what to do. The home has nothing going for it structure-wise: vaulted ceilings in three upstairs bedrooms, huge glass sliding doors all over the house, and a lot of windows. Fireplaces upstairs and downstairs.

One 3.5 ton unit serves one floor and a 4.0 ton unit serves the other floor. Units have to run constantly for the retired tenants to keep comfortable, either warm/cool. Spring and fall not so bad.
 
Usually cannot go wrong with Carrier. They cost more but I have them in my home and in a rental house on the Outer Banks of NC and they are generally much better than the Trane units and other models they replaced. Whatever you do, go for the highest SEER if you want to reduce costs. And if these are running constantly, they sound like they are undersized. With them being so old, I'd want to replace the indoor and outdoor units both.

As for other power costs: Does this place have a lot of recessed ceiling fixtures with flood lamps?
 
Flood lamps around the outdoors, not inside.

The article I just read mentioned that only are few brands rate as premium, namely Carrier and Bryant, Trane and American Standard, and Lennox.
 
Would also suggest Ceiling fan for the vaulted ceilings. Have seen top registers and top returns, hard to get air flow down low if it stays on top. Maybe look at air flow patterns with a smoke generator.
 
dibbons said:
By indoor unit, you mean the "air handler"?
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Yes, which includes the inside heat exchanger coil. The new fans can vary speeds and be more efficient.

Carrier owns Byant now... Bryant was really better at furnaces, so the Bryant A/C's are now downscale Carrier units. Lennox is good. Both lines are distinctly better than Trane in my experience.

How cold does it get there in winter?And how damp? If the temps regularly get below 35-40F, and there is any real dampness in the air, then the outside units ice up, and will have to go into thaw mode, which uses a lot of electricity. So heat pumps get inefficient at low temps in moist conditions.

OK, on the lamps. We found that copious numbers of ceiling recessed fixtures use a lot of juice, so thought I would ask.
 
Not real cold frequently, but last week tenants complained of unit icing up.
According to MSN weather, average low in December is 39.
 
dibbons said:
Not real cold frequently, but last week tenants complained of unit icing up.
According to MSN weather, average low in December is 39.
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If they are icing up, they are likely low on Freon. It’s usually the first sign the system is failing...and probably leaking.
 
I pulled my builder special and replaced with a Rheem. The attic unit went from a 50 and 30 amp 240 feed for heat to a just a 40amp 240 feed. The heat pump outside was 20 and went to 30 amp, My cost savings bought me a mini-split to put in the garage and just used that now unused 30amp house feed with a breaker change to 20amp. I now heat and cool the house and garage for less than what it was costing just for the house. Technology changes!
 
I switched my 2 units on my rental house in Memphis (one upstairs, one downstairs) to a Heil dual fuel system. Heat pump for AC and heating down to 45*, then it switches to natural gas fired heat below that.

It cut the energy bill in half.
 
Ddaddy said:
If they are icing up, they are likely low on Freon. It’s usually the first sign the system is failing...and probably leaking.
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The outside coils will ice up whenever the outside temp is low enough and the humidity outside is high enough. Happens with a perfectly running system.... which is why they have reversing valves to thaw themselves out. If very dry air is outside, they can run down to the 10F, but again, get pretty inefficient under those situations.

And some sort of backup to cover the situations when they just won't run efficiently (or at all with really cold, dry conditions). Electric resistance heat is a common backup, but gas is a good one for colder climates. As with DDdaddy's system, our home system uses LP gas as a backup, and switches to that below 35F. The bonus is when it goes to the gas backup, we get nice warm air, much more comfy.
 
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No gas lines in a rural area, firewood is their back up for now (electric blowers in the fireplaces). Maybe pellet stove inserts would provide more heat.
 
dibbons said:
No gas lines in a rural area, firewood is their back up for now (electric blowers in the fireplaces). Maybe pellet stove inserts would provide more heat.
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An LP tank is also an option to fuel the Winter heat.
 
I've been out of the business for so long, my advice is dated, but here:

"Used to be" the lower priced units were "less" on safeties/ protection for the compressor, IE hi pressure/ low pressure cutoffs, and what "was then" just generalized into "outdoor thermostats". These were often an accessory, not necessarily provided, that sense OD temp and switch the system from heat pump operation to only using aux/ emergency heat, which is most often simply electric heat. This is the same heat that provides duct heat during defrost.

Most heat pumps are basically two systems in one. Most the air handler is basically an electric furnace with the heat pump ID coil. In some areas, the electric heat is marginal. You for certain want to be sure the electric heat is "sized" to provide full room heating in case the heat pump dies

So regardless of pricing make certain the unit does not scrimp on these features..........

Low / high pressure/ temp cutoffs to protect the compressor
Adequate backup/ emergency/ auxiliary heat for heating and defrost
Outdoor sensors/ thermostats to regulate the system in cold weather
And make sure the unit AND ductwork is properly designed and sized.

These things are MUCH more critical for heat pumps than any other systme, including AC
 
nm9stheham said, "Whatever you do, go for the highest SEER if you want to reduce costs." And he is absolutely correct. Just going to very high efficiency units should reduce operating costs about 40% from 1979 units.

Actually, spending $1000 to heat or cool a 4000 s.f. house is not that far out of line, even though Climate Zone 3 is relatively mild. PG&E has a very penalizing rate structure when you use a lot of kwhr per month. And now that they will have to pay for the forest fires, it is going to get worse.

So,
1. Get hi-eff units. New units will require that the contractor check the ducts for leakage.
2. Have tenants raise or lower (depending on season) thermostats by 2 or 3 degrees.
3. Have tenants try to live in one part of the house as much as possible, so one unit can be turned off.
4. Make sure you have at least 6" of attic insulation. Other home improvements are not really cost effective, unless there is a lot of single-pane glass.
Done.
 
I would not worry about SEER at the expense of system quality, duct design, AND LOCAL SERVICE. Buying a super duper efficient unit does you no good if it or the ductwork is not properly engineered, or if nobody in the local area can service the thing...........because they are ALWAYS gonna break on the coldest days...........

Any new units sold lately are going to be at least "in the ballpark" on SEER.
 
Everyone has made good points, even though we are not in agreement on everything. It has become a complex subject like everything else these days. Nothing like the good-old fashioned campfires of the stone age (or last century, for that matter).
 
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