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Mechanical Contractors and Energy-Efficient HVAC


What Mechanical Contractors Need to Know about Energy Efficiency and HVAC

Building owners rely on your expertise. But it takes trust to make this possible. And to create it, you want to ensure they’re receiving the HVAC solution that makes the most sense for their facility and budget.

You already know that top-line price isn’t the most important factor in determining the cost of equipment.

And it’s impossible to have conversations about lifecycle cost without talking about energy efficiency. Your customers are going to be invested in reducing their monthly energy bill. Reducing that translates to more business.

Heating: Direct-fired HTHV tech, unit heaters and heat pumps

You want to heat big spaces and your customer doesn’t want to pay big bills. How do you do it?

For large commercial spaces, direct-fired technology offers a clear pathway to energy efficiency. Without heating loss via a flue, direct-fired heaters achieve 92% thermal efficiency, meaning that 92% of all therms provided to the unit are provided to the building as heat. Indirect-fired heaters make more sense for smaller, enclosed spaces (like your home), due to the lower risk of pollutants entering the airstream. 

That shouldn’t lead you to think direct-fired technology supplies poor air quality. Direct-fired High Temperature Heating and Ventilation (HTHV) units mitigate this issue by using entirely outside air to provide ventilation that meets building codes that standard unit heaters can’t on their own.

As an HTHV space heater, the Cambridge S-Series goes further than its peers to provide energy efficiency. It’s the only product capable of reaching a discharge temperature of 160 °F, so you don’t have to heat as much air tomeet a building’s heat load requirements. That minimizes the size of the overall unit and fan motor. And with high velocity discharge destratification technology, it forces warm air to ground level, where it’s needed most. 

Still, unit heaters have grown more efficient, though not at the levels of HTHV space heaters. Condensing unit heaters can pass 90% efficiency, while standard unit heaters still hover around 80% efficiency. These condensing units require some maintenance — caustic condensate needs to be disposed of safely.

But let’s address the electric elephant in the room. If you’ve spent time in the HVAC world recently, you know that the major new players in energy-efficiency are heat pumps. Heat pump energy-efficiency is very, very high — in right-fit, smaller commercial facilities and residential homes, they easily outperform alternatives.

But they can struggle to warm larger buildings quickly and consistently — especially when supported by insulation that’s anything less than perfect. And when outside temperatures fall very low, heat pumps need an auxiliary heat source to function. Plus, installation is a complicated, lengthy challenge (especially for retrofits), contributing to slow heat pump adoption in large commercial and industrial facilities and exceedingly high upfront costs.

Ventilation: Make-up air and recirculation

Cleaner air with a cleaner energy footprint. Let’s dig into it.

Make-up air is built for facilities that need ventilation to reach safety and air quality standards. It’s designed to bring fresh, tempered outside air into your facility to replace air exhausted by machinery and other industrial processes. And it reaches far better IAQ ratings than typical ventilation fans.

To bring in outside air, some heating is often required. And just like with heaters, a direct-fired make-up air unit will provide stronger energy efficiency than an indirect-fired alternative. But there are more details to consider than the presence of a flue.

A key component here is fan efficiency. There have been changes to fans over the years as manufacturers improve designs. A typical option here is forward curve fans (like in Cambridge’s M-Series), but alternatives exist.

Some mechanical contractors opt for recirculating air instead of make-up air for ventilation. While recirculating air can be more energy-efficient, it won’t ensure good air quality in a facility where equipment produces pollution and in some cases (such as ASHRAE 62.1 Class 3 and 4 air zones), recirculation is prohibited. 

For instance, you couldn’t recirculate 200,000 CFM of exhaust air. And in some regions, like Canada, green energy codes don’t permit recirculated air at all.

Cooling: Evaporative and mechanical

Your options for cooling a large facility efficiently depend on where you’re located.

Live in the Southwest or other, more arid parts of the country? Then you already have plenty of experience in facilities that make use of evaporative cooling

Unlike mechanical air conditioning, where compressors and a refrigerant loop have to be powered by electricity, the energy source of evaporative cooling is water. That makes it inherently more energy-efficient than traditional air conditioning, which can run up energy bills fast.

The tradeoff: Evaporative cooling relies on drier outside air conditions for maximum efficiency. So while it is the most cost-effective and energy-efficient choice for building owners who want to make their facilities more comfortable, but aren’t completely committed to staying at 68 degrees all day. 

Even in those cases, you can always add DX coils to evaporative cooling equipment (like the Cambridge ESC-series) to include a mechanical cooling element. Some building owners choose to double up on evaporative and mechanical cooling equipment, committing to higher upfront costs but discovering budget-altering energy savings in the long term.

For contractors, another benefit of evaporative cooling comes down to its ease of installation. You don’t need condenser coils or chillers or to run the equipment through the entire building. It’s just a single unit. And Cambridge makes installation easier by delivering key components in a single package with lead times weeks or months earlier than alternatives.

A note on decarbonization

You might have heard the buzz about decarbonization, the policy effort to reduce our infrastructure’s carbon footprint. And your customers may be invested in this shift, too. 

We’ve been moving toward greater energy efficiency in HVAC for a long time. But aside from the standard temptation of lower monthly bills, regulations and green energy incentives from the government have pushed mechanical contractors and building owners to take action. 

Incentives for energy-efficient natural gas equipment exist in many states, but not all of them. Cambridge builds highly energy-efficient natural gas technology because it’s the right choice for plenty of contractors and building owners in terms of cost, performance and sustainability. 

If you’re speaking to a building owner interested in reducing their carbon footprint, our solutions work. We know the efficient usage of natural gas is a crucial touchpoint for decarbonization. Electricity grids still run on carbon — and that carbon is utilized less effectively than it should be. 

Want to talk about the options where you live? 

Your local Cambridge rep understands the options for energy-efficient HVAC in your region and how they intersect with local regulations and incentives. 

Find them today. A no-pressure conversation gives you insight into what equipment your customers are going to need. Now, and in the future.

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