Rethinking DOAS: Strategies to Increase Energy Efficiency [Product Showcase]
Innovative DOAS Units From Petra and RenewAire
Dedicated Outdoor Air Systems (DOAS) consist of two parallel systems:
- A dedicated system for delivering outdoor air ventilation handling both latent and sensible loads for conditioning the air
- A parallel system to handle the loads generated by indoor/process sources that are mostly sensible heat
DOAS units maximize energy efficiency and cost savings, particularly in the form of innovative Petra and RenewAire systems. Here we’ll take a look at each one and explain the best strategies and approaches.
PRODUCT SHOWCASE: PETRA
About Petra
Petra was founded in 1987 with a broad vision to produce a wide variety of HVAC equipment for the global market. By 1994, Petra expanded its line of HVAC equipment utilizing some of the industries most advanced machinery, components and raw materials to achieve the highest quality and efficiency standards.
Petra offers a wide range of products, such as DOAS Units, Custom & Semicustom AHUs, Energy Recovery Units, Custom Chillers, CRAH/CRAC Units and more. Consequently, Petra established itself as a trusted manufacturer with an impressive list of clients worldwide, including within the U.S.
Petra Heat Recovery Dedicated Outdoor Air System (DOAS) PPH
Standard features:
- 3,000 to 20,000 CFM
- Dedicated outdoor air
- Delivers neutral air to space for ventilation year-round
- Cooling efficiency up to 19 EER
- Heating efficiency up to 6.5 COP
- Outdoor or indoor installation
- Integrated microprocessor controller for stand-alone or BMS operation
- Capacities ranging from 7.5-50 tons
- Refrigeration cycle changes direction depending on heating or cooling mode
- Able to accommodate unbalanced airflows
Series heat pipe optional feature:
- Heat pipe absorbs energy from warm humid outdoor air
- Pre-cooled air exits the first heat pipe reducing the load on the cooling coils
- Over-cooled air exits the coil and is reheated to dry comfortable air from the energy recovered by the heat pipe
PRODUCT SHOWCASE: RENEWAIRE
About RenewAire
RenewAire has been a pioneer in Energy Recovery Ventilation technologies for over 35 years. Their Energy Recovery Ventilators (ERVs) improve people’s health, cognitive function, productivity and wellbeing by enhancing indoor air quality (IAQ) in homes and buildings of every type. This is done energy-efficiently, cost-effectively and sustainably via fifth-generation, static-plate, enthalpy-core ERVs and Dedicated Outdoor Air Systems (DOAS) that reuse otherwise-wasted energy to condition incoming outdoor air.
RenewAire DN Series DOAS
- Split DOAS units with static-plate, total energy recovery
- 375-4,950 CFM
- Single-point connection, direct-drive EC fans, injected foam panels
- Modular design
RenewAire DN Series DOAS with Integrated Refrigeration
- Split DOAS units with static-plate, total energy recovery
- Integrated refrigeration
- 375-4,950 CFM
- Brushless DC compressors
- EC motors on all fans
- Modular design
RenewAire RD Series DOAS
- Commercial DOAS units with static-plate, total energy recovery
- Bypass
- Optional coils
- 500-4,250 CFM
DOAS POWER RANKINGS
Power Rankings: DOAS Units
Below are HIGHMARK’s top five power rankings for DOAS designs. More than just efficiency, the rankings also consider maintenance, indoor air quality and controllability. They’re organized into three categories:
- DOAS Design: We start with number five and work our way up to the top DOAS design
- Features: We list out what’s included, and what’s not, in each design
- Benefits: We explain what the benefits are of each design using this key: 1) $ = cost savings, 2) Lightning bolt: energy savings, 3) Sprout: support for the environment
DOAS Design #5
Features
- 100% outdoor air
- No heat recovery
- Hot gas reheat
- Auxiliary heat in winter conditions
Benefits
DOAS Design #4
Features
- 100% outdoor air
- Energy recovery unit with energy wheel
- Return air pre-treats incoming outdoor air
- Reduces size of cooling coil
- Hot gas reheat
- Auxiliary heat in winter conditions
Benefits
DOAS Design #3
Features
- 100% outdoor air
- Energy recovery unit with enthalpy core
- No cross-contamination
- No moving parts/less maintenance
- Return air pre-treats incoming outdoor air
- Reduces size of cooling coil
- Hot gas reheat
- Auxiliary heat in winter conditions
Benefits
DOAS Design #2
Did you know? Adding a second layer of energy recovery reduces required mechanical tonnage by 17%.
Features
- 100% outdoor air
- Energy recovery unit with two layers of heat recovery
- Enthalpy core and heat pipe
- No cross-contamination
- No moving parts/less maintenance
- Return air pre-treats incoming outdoor air
- Heat pipe reduces size of cooling coil and cuts energy use for hot gas reheat
- Auxiliary heat in winter conditions
Benefits
DOAS Design #1
Features
- 100% outdoor air
- Energy recovery unit with two layers of heat recovery
- Enthalpy core and heat pipe
- No cross-contamination
- No moving parts/less maintenance
- Return air pre-treats incoming outdoor air
- Heat pipe reduces size of cooling coil and cuts energy use for hot gas reheat
- Condenser coil located inside the unit that releases heat into the exhaust airstream and removes the need for an additional auxiliary heat source in winter
Benefits
