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Heat pumps & electrification
Everything here is either a physical fact or a question we ask about your house. There are no promises about savings, because the honest answer to that one depends on your rate plan.
It moves heat instead of making it
A furnace burns fuel to create heat. A heat pump does something different: it runs a refrigeration circuit, absorbs heat from the outdoor air, and releases it inside. In summer it runs the same circuit in the other direction and becomes an air conditioner.
There is usable heat in air well below freezing, which is why this works at all. And because the machine is moving energy rather than converting it, it can deliver several units of heat for each unit of electricity it draws. That ratio is why the efficiency figures look wrong the first time you see them.
- Ducted
- An outdoor unit and an indoor air handler, using the ductwork you already have. The closest thing to a like-for-like replacement for a furnace and air conditioner.
- Ductless
- One outdoor unit and one or more indoor heads, no ducting at all. The answer for additions, ADUs, garages and houses that never had ducts.
- Dual fuel
- A heat pump with the existing gas furnace retained as backup. Rarely necessary in this climate, but occasionally the right staged answer where a panel upgrade is being deferred.
The panel question
This is the part of electrification that surprises people, and it is the reason this page exists.
A heat pump needs a circuit. So does an EV charger, an induction range and a heat-pump water heater. Those four things arrive in a household over several years, usually installed by different trades, none of whom is looking at the whole picture. The panel that was generous when the house was built is not necessarily generous now.
- What we check
- The existing service size, what is already connected, spare breaker positions, the condition and type of the panel itself, and where the meter and main are.
- Measured load
- Not nameplate arithmeticCalifornia's code allows an electrical load calculation based on actual measured demand rather than adding up every appliance's maximum rating. That difference frequently decides whether a service upgrade is required at all, and it is worth doing properly.
- If an upgrade is needed
- You hear it at the assessment, with a realistic figure, before any equipment is chosen. A service upgrade involves the utility as well as an electrician, and the lead time is often longer than the HVAC work.
- Ways around it
- Sometimes there are: load-management devices, a smaller or more efficient unit, staging the work differently, or circuit-sharing solutions. Sometimes there are not, and we say so.
To be clear about scope
We are a C-20 mechanical contractor. We assess the panel, produce the load calculation and coordinate the work — the service upgrade itself is carried out by a licensed electrical contractor. We would rather tell you that than imply we do everything.
Your ductwork decides whether it works
A heat pump generally moves a larger volume of air at a lower supply temperature than the furnace it replaces. A furnace can push 130°F air through a restricted duct system and you will still feel warm. A heat pump delivering air in the nineties cannot hide a bad duct system at all.
This is the most common reason people are disappointed by a conversion, and it is entirely preventable with an hour of testing beforehand.
- Total external static pressure measured
- Return grille area checked against the airflow required
- Leakage assessed, particularly in unconditioned space
- Insulation condition on attic and crawlspace runs
- Register airflow measured room by room
- Filter slot depth — a restriction most people never consider
Where the ducting needs work, it is priced as part of the project rather than presented as an unfortunate discovery later.
Running costs, honestly
This is where most heat-pump marketing becomes unreliable, so here is the actual shape of the arithmetic.
| Factor | Works in the heat pump's favour | Works against it |
|---|---|---|
| Efficiency | Delivers several units of heat per unit of electricity | A gas furnace delivers slightly less than one unit per unit of gas |
| Energy price | — | Electricity costs considerably more per unit than gas in California |
| Your rate plan | Time-of-use plans can be favourable if the house is heated off-peak | Tiered plans can push a large new load into an expensive tier |
| Solar | Changes the calculation substantially, particularly for cooling | Export rules matter and have changed; worth checking your own arrangement |
| The gas meter | Removing the last gas appliance removes the standing charge entirely | Only applies if nothing else on the property uses gas |
| Cooling | You are buying air conditioning at the same time, which gas cannot provide | — |
What we will not do
We will not put a savings figure on a quote. There are too many variables that belong to you rather than to the equipment — your rate plan, your usage pattern, whether you have solar, what else is on the gas meter. What we will do is run the arithmetic with your actual numbers during the assessment and show you the working.
How a conversion runs
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Assessment
Load, ducts, panel and rate plan. Two to three hours, and the output is a written picture of your house rather than a quote for a box.
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Options
Usually two or three, priced, including any duct or electrical work. Where waiting is the better option, that is presented as one of them.
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Coordination
Permit, Title 24 documentation, rebate paperwork, and scheduling with an electrician if a service upgrade is part of the job.
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Commissioning
Charge verified, airflow measured at every register, controls set up, and the readings left with you.
About heat pumps
How does a heat pump actually heat a house?
It moves heat rather than creating it. A refrigeration circuit absorbs heat from the outdoor air — there is usable heat in air well below freezing — and releases it indoors. Because it is moving energy rather than burning fuel, it can deliver several units of heat for each unit of electricity it consumes, which is why the efficiency figures look implausible to people meeting them for the first time.
Why does the electrical panel matter so much?
Because a heat pump is one of several large electrical loads that modern households add to an old service. An EV charger, an induction range and a heat-pump water heater are all substantial, and they are usually installed years apart by different trades. A 100-amp service that was generous in 1968 can run out, and the resulting service upgrade is frequently the largest single line in an electrification project.
Do I have to replace my ductwork as well?
Not necessarily, but it must be tested. A heat pump generally delivers a larger volume of air at a lower temperature than the furnace it replaces, so a duct system that was just adequate can become inadequate. Measuring static pressure and checking return sizing costs very little and prevents the most common cause of disappointment after a conversion.
What happens to my gas furnace and its flue?
In a full conversion the furnace is removed and the flue is decommissioned and sealed properly. If a water heater still shares that flue, it changes how the flue must be handled, which is one of the details worth catching at the assessment rather than on the day.
Is there ever a reason not to convert?
Yes, and we will say so. A panel upgrade that costs more than the equipment, a duct system that needs replacing first, or a furnace with years of life left are all sound reasons to wait or to stage the work. Electrification is usually a good idea here; it is not a good idea in every house on every timetable.
Find out where your house actually stands
Building, ducts, panel and rate plan — before anybody chooses equipment.