Conventional Systems vs. Mitsubishi Inverter Heat Pump Systems
In the HVAC industry, we are asked a plethora of difficult questions, such as:
- Why did this part fail?
- How much is this going to cost?
- How much money will I save?
- When will it pay itself back?
- And, which system is best for my home?
With the complexity of HVAC systems, and the variability of the weather, design factors, home construction, and installation practices, every one of these questions is very challenging to answer! Today, I’d like to examine the concept of Conventional Heating VS Mitsubishi Inverter Heat Pump systems, to discuss their practical uses and when each might fit better than the other.
When speaking of conventional heating systems, I am generalizing what we call “Unitary” systems, consisting of gas or oil-fired furnaces and boilers. In general, these systems are what most of you have in your home already. You might have some duct work in your basement or attic, you might have a boiler and associated piping to baseboard heat or radiators, or you could also have a combination of the two. In terms of the overall efficiency of these systems, think about it this way – The system burns some sort of fuel to generate heat, and there are several steps along the way where it can LOSE that heat and efficiency. It starts right at the gas fired heat exchanger, which generally only transfers between 80% – 95% of the fuel consumption to real British Thermal Units (BTUs). From there your system experiences loss in your duct work via air leaks in the ducts (dumping “lost” air into either your attic or basement), loss in the copper heat piping that runs throughout the basement or in the walls, or loss as a combination of those two things in a hydro-air system. This inefficiency has been incrementally improved over the years, by improved annual fuel utilization efficiency (AFUE) at the burner, enhanced code requirements on duct sealing and insulation, and overall installation practices. Here are some situations where conventional systems seem to fit best:
- In older homes that were constructed prior to Inverter Heat Pump technology becoming a great heating option.
- Hydronic systems in homes where air conditioning was never really considered a priority.
- Hydronic systems in homes where radiant floor heating is a priority.
- Forced air systems where duct work provisions have been made during construction.
- General new construction where the intended homeowner or builder do not “trust” inverter heat pumps for primary heating.
In my opinion, the reason most homes in New England DO use conventional heat, is a combination of the reasoning above, with a strong emphasis on the last bullet point. The bottom line is that many locals and trade professionals still just do not trust a heat pump to do the work required to heat a home in the dead of winter.
Mainly in the last five years, there has been a significant shift in the mindset of forward-thinking HVAC circles, that Inverter Heat Pump solutions are an excellent solution for both new homes as well as retrofits. If you align the bullets below with those above, there is a great counterargument for each of those points above.
- Inverter Heat Pump (IHP) technology IS now a great heating option, and can easily be retrofitted into homes that currently have conventional systems.
- With heat pumps in general, air conditioning is an automatic benefit with installation, as any heat pump will provide cooling to the space during summer.
- In general, small areas such as master bathrooms can utilize an efficient electric heat mat beneath tiling to satisfy those looking for warm toes.
- Although some Mitsubishi Electric systems DO use duct work, many of them are ductless, thus freeing up floor space, basement space, and reducing the need for chases or sofetting throughout a newly constructed home.
- Refer back to point one – These systems have now been proven, to be efficient in our Seacoast climate, and well North of here.