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Gas furnace in total electric house.


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Today I did an inspection and found little stuff, nothing out of the ordinary, although a "handy-man" or the home owner, unknown honestly did a total complete remodel of the house.

I assume he did the furnace also.

I opened up the furnace and noticed many wire nuts inside all taped with vinyl tape. Several micro-chip boards laying in the bottom of the cabinet. and several fuses installed throught the circuitry (commonly installed to short fuse instead of a $350 circuit board which was not installed).

The house was about 70 degrees upon arrival. And the vents were blowing about 89-91 degree air.

I began my sequence of checking stuff on the furnace. When i turned the thermostat up to watch the sequence the squirrel cage immediatly came on. Nothing else happened.

I figured out that the heat pump was running on regular heat, and when i turned it to emergency heat. The gas line was not hooked up. The house was not hooked up with gas.

The house is being heated with a heat pump only. Nothing about the gas furnace works, the draft inducer, electric valve everything is bypassed and have no juice whatsoever.

Has any one ever heard of this before? It seems like an odd occurance, but was kind of humurous.

The unit is a 2002 unit. So I know that it has lasted for 8 years of use.

I know its incorrectly installed/wired, but as long as the wiring is safe/correct and the evaporator pool (I'm starting to get past my limited knowledge of hvac as I am still learning) is correct, could this be a viable function if you dont mind your electric meter spinning quite fast?

Thanks, Matt

Oh and its a Goodman unit

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To make sure I was clear,

The electric heat pump is the ONLY source of heat, there is a gas furnace inside but its completely bypassed.

There is no Natural gas available to the home's area, nor is there a propane tank on the premise.

Where I'm from originally most central heat units are electric.

Since I moved to Northern Oklahoma, I've seen mostly gas furnaces.

When there was a heat pump system on a gas furnace in Texas, it was not used as the main source of heat either, But my question is the not this. There is NO gas supply to the house, let alone the heater. All the HSI circuitry and micro chip boards have been removed with a pair of wire cutters. Then bypassed with wire and wire nuts.

When you put the thermostat on heat OR Emerg the heat pump automatically kicks on, Neither one affects the gas part.

Sorry If I'm not very clear on my writing. There is a reason I have my work proof read for clarity =)

Matt

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I understand a little better now, thanks. So, it seems that a new heat pump system was purchased to replace the original gas powered furnace except that the original gas furnace with the blower within it was retained and custom rewired to supply the needs of the new indoor heat pump coil. I'm assuming that the new inside coil came with the heat pump system in it's own cabinet and was attached to the original gas powered furnace/blower assembly.

Do I have the correct picture?

Marc

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Similar, I guess the old Electric heater went out.

Home owner bought a gas unit to replace his electric unit (good deal?

Home owner cut out all that electronic crap and wired the Heat pump to work when the thermostat is turned to heat

There was never gas to the home.

Someone replaced and electric with a gas, and decided to use heat pump instead of buying a electric heater. He had to do alot of re-wiring to create this monstrosity.

It may be my explaining thats confusing you Marc =P

Thanks for the interest

Matt

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It sounds like a clear case of 'backyard' engineering to me. Your client would certainly not look, with boundless joy, upon someone's tinkering with the HVAC system on such a large scale, so I'd be sure to describe this finding in the report and to recommend that a qualified HVAC contractor return the system to an 'industry approved' installation.

Marc

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So How did it work with all that snow covering the condenser this weekend? I used to see it when the flips were hot and heavy. Haven't seen it for several years now. The funnest one was when it was a heat pump but the furnace was replaced than the outside condenser a moth later with a none heat pump. Worked in cooling mode, but when you turned it to heat well it cooled as well.

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Heat pumps are the champion here in Central VA. and are found in probably 50% to 60% of the homes. Heat pumps with natural gas or propane furnaces as the backup heat source were the Cadillac installation here for many years.

I do not have an HVAC background, so some of what I'm about to explain may be somewhat off the mark and more accurate info is more than welcome.

As the energy efficiency of heat pumps has markedly improved, they appear to depend considerably less on the backup heat mode. While gas is a far more efficient heat source, it has fallen out of favor here, which I suppose has to do with the volatility of gas prices and the reduced part that backup heat plays.

The performance of heat pumps has improved so much that when I replaced my 14 year old heat pump, my power bill was reduced by just about 50%, which was a pleasant surprise. The new generation of heat pumps seem to be able to work well in much lower temperatures. Some of this is accomplished by variable (slower) condensing unit fan speeds, which permits the coil and refrigerant slightly more time to gather heat in colder temperatures. I notice that the heat pumps no longer cut completely off when the backup heat kicks in, but rather works in unison with the backup heat.

Another marked improvement in heat pumps is an increase in register air temperatures from the 90's to approximately 110. I believe this increase in register temperature has made larger ducts, which was really about reducing air speed to make 90 degree air more tolerable, no longer as critical to comfort.

I don't think I've ever seen a heat pump without a backup heat source. Can a heat pump without backup heat suffice in Oklahoma?

It seems to me (if I read all this right) that maybe the upgrade was being performed in stages - as funds permitted and the apparent intent, was gas (most likely propane) back up. The heat pump would then operate in the "heat" mode and the gas furnace operate in "aux" or "emer" modes.

As Marc has said, "its bread ain't done". But, again, my guess is it was a work in progress...

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Call for a complete evaluation and repair by a qualified technician.

This is a hack job that will likely not perform adequately in very cold weather.

It may work but it is not installed per the manufacturers listing.

Strip heaters may be possible but let a tech make that call.

The first time a real tech opens the panel, he will certainly bring it to the attention of the home owner and you will be the one with egg on your face if you don't call it out first.

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I know its incorrectly installed/wired, but as long as the wiring is safe/correct and the evaporator pool (I'm starting to get past my limited knowledge of hvac as I am still learning) is correct, could this be a viable function if you dont mind your electric meter spinning quite fast?

No. It's been severely hacked* and in your climate, a heat pump needs to have reliable supplemental heat.

I'd be advising the client to have a damn good (real) heat pump installed.

*Hack, hacked, hack·ing: to damage, injure, deform or alter by crude, harsh, or insensitive treatment; mutilate; mangle

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Thanks for all the input guys, I think the client called a HVAC right after we left the scene of the "incident" and they said it needs to be replaced, I think they will go with a "heat strip" heater.

Now, This is new to me, but are yall saying that some people use a heat pump (reversal of AC) as a primary heating element?

Matt

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The heat pump, by design, is always the primary system with some form of backup heat behind it to take over or supplement when the heat pump can't keep up. The beauty of the system is that heat is not being created (no on site fuel burned), but rather gathered and moved as it already exists in the air. Although, there is actually some heat generation when the refrigerant, in a gas state, is compressed (super-heated) by the compressor. Even the compression phase is more a compounding of existing heat. The only significant inefficiency is that a huge amount of energy is lost during delivery of electricity to the home via transmission lines.

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I live in Eastern Ontario, right now outside temp is -20c. My Air Source Heat pump is the priamry source of heat. When the temp differential is below -15c the aux and emerg heat coils start up. I do have a wood stove for days like today when its more effiecient to have supplemental heat than have the aux heat from the heat pump. I modified the cold air return to pick up some of the heated air in the basement and have it pass thru the plenum, then recirculate it to all elevations. If I can keep my basement warm at -20c outside the whole house is warm. I had an HE Oil stove in my last house. Worked great, but fuel cost went crazy. They tried to convince me to switch to Gas, forget that. Pound for pound gas cannot compete with anything. The only thing I see good about gas is that it is clean burning. The fact that the supplier has a line running to my house and he controls the cost of it is aikin to holding a gun to my head,,, so no to gas, yes to heat pumps and for supplemtal heat a wood stove is the answer. Well its my answer I live beside a forest, and I own an axe or two. Oh yeah, my electrical bill is at least 30% lower than when I was using just oil . I also factored in the cost of wood, still cheaper and cleaner. No fuel smell inside the house and I can dig anywhere outside without blowing up the area.

my two cents are free

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Heat pumps in Canada - a couple years ago here I predicted this day coming (efficient cold weather heat pumps) and was immediately stoned! Heat pump technology is pressing on like a freight trane. I've run across some systems that had tandem condensing units or two coils in one condensing unit on top of everything mentioned above. The advancements are no less than amazing.

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Heat pumps in Canada - a couple years ago here I predicted this day coming (efficient cold weather heat pumps) and was immediately stoned! Heat pump technology is pressing on like a freight trane. I've run across some systems that had tandem condensing units or two coils in one condensing unit on top of everything mentioned above. The advancements are no less than amazing.

And that is exactly why ground source units are still relatively rare.

Tom

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Heat pumps in Canada - a couple years ago here I predicted this day coming (efficient cold weather heat pumps) and was immediately stoned! Heat pump technology is pressing on like a freight trane. I've run across some systems that had tandem condensing units or two coils in one condensing unit on top of everything mentioned above. The advancements are no less than amazing.

And that is exactly why ground source units are still relatively rare.

Tom

That, and the enormous expense of installation.

FWIW, I've seen exactly 3 heat pumps in Denver in a decade in this business. I've always assumed it's due to cheap natural gas rates because we're closer to the source.

Garet

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The catholic church in town is huge by anyones standards. Only those, like me , who ask, 'that must be a brick to heat' hear the response, the parking lot is the cover for the ground source heat pump. Not having any reason to go in there beyond curiosity, I found out that they heat it up very well in the winter and is an excellant source of AC in the hot summer week we get up here. It is quite deeply layed, couldnt find out further info.

Being a home owner twice over, I would make one change to my heating, and that is 'hydronic in floor/slab radiant'. Any one living up here thinking about building, is not thinking of themselves when they build for the winter, forced air, regardless of how you heat it up has many drawbacks . The cost of radiant heating will be recovered in the short term. And my generator will power it during the blackouts (often)..

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