Relative Humidity Set Points Research Articles

Mustard ‘Amara’ Benefits from Superelevated CO2 While Adapting to Far-red Light Over Time

Compared with the ambient Earth carbon dioxide concentration (≈415 μmol⋅mol–1), the International Space Station has superelevated carbon dioxide (≈2800 μmol⋅mol–1), which can be a stressor to certain crops. Far-red light can drive plant photosynthesis and increase extension growth and biomass. However, the effects of far-red light under superelevated carbon dioxide are unclear. We grew hydroponic mustard (Brassica carinata) ‘Amara’ seedlings in four growth chambers using a randomized complete block design with two carbon dioxide concentrations (415 and 2800 μmol⋅mol–1), two lighting treatments, and two blocks at temperature and relative humidity set points of 22 °C and 40%, respectively. Each growth chamber had two lighting treatments at the same total photon flux density of 200 μmol⋅m–2⋅s–1. Under the same blue and green light at 50 μmol⋅m–2⋅s–1 each, plants received either red light at 100 μmol⋅m–2⋅s–1 or red + far-red light at 50 μmol⋅m–2⋅s–1 each. At day 15 after planting, far-red light did not influence shoot fresh or dry mass at 415 μmol⋅mol–1 carbon dioxide, but decreased both parameters by 22% to 23% at 2800 μmol⋅mol–1 carbon dioxide. Increasing the carbon dioxide concentration increased shoot fresh and dry mass 27% to 49%, regardless of the lighting treatment. Far-red light decreased leaf area by 16% at 2800 μmol⋅mol–1 carbon dioxide, but had no effect at 415 μmol⋅mol–1 carbon dioxide. Increasing the carbon dioxide concentration increased leaf area by 21% to 33%, regardless of far-red light. Regardless of the carbon dioxide concentration, far-red light promoted stem elongation and decreased chlorophyll concentrations by 39% to 42%. These responses indicate far-red light elicited a crop-specific shade avoidance response in mustard ‘Amara’, increasing extension growth but decreasing leaf area, thereby reducing light interception and biomass. In addition, carbon dioxide enrichment up to 2800 μmol⋅mol–1 increased the biomass of mustard ‘Amara’ but decreased the biomass of other crops, indicating crop-specific tolerance to superelevated carbon dioxide. In conclusion, mustard ‘Amara’ seedlings benefit from superelevated carbon dioxide, but exhibit growth reduction under far-red light under superelevated carbon dioxide.

Effects of humidification process on thermal performance of floor heating systems: An experimental study

In dry and cold climates, a cool mist humidifier and a floor heating system are typically used in combination to achieve a pleasant residential environment. In order to investigate the interaction between a humidification process and a heating process, a total of 12 experimental tests were carried out, which included nine experimental groups with a humidification process under the conditions of three indoor temperature set points (21 °C, 23 °C, 25 °C) and three relative humidity set points (45%, 55%, 65%), and three control groups with no humidification process under the conditions of three indoor temperature set points (21 °C, 23 °C, 25 °C). Obtained results show that the indoor environment will reach a new balance in the process of competition between the evaporative cooling and the floor heating, and the floor surface temperature increases when the humidification level rises. The floor overheating problem should be considered while meeting humidification needs at air temperatures of 25 °C or above. The humidification process makes the air temperature distribution more uniform, but increases the energy consumption noticeably. In addition, exergy loss is mainly concentrated in two areas: the building envelope and the floor for the floor heating system. In summary, the set point of RH 45% could meet general health requirements in the case of minimal energy consumption. RH 55% could be selected at below 25 °C for better thermal comfort in particular situations where the energy consumption is acceptable.

Development and Calibration of Pressure-Temperature-Humidity (PTH) Probes for Distributed Atmospheric Monitoring Using Unmanned Aircraft Systems.

Small unmanned aircraft systems (UAS) are increasingly being used for meteorology and atmospheric monitoring. The ease of deployment makes distributed sensing of parameters such as barometric pressure, temperature, and relative humidity in the lower atmospheric boundary layer feasible. However, constraints on payload size and weight, and to a lesser extent power, limit the types of sensors that can be deployed. The objective of this work was to develop a miniature pressure-temperature-humidity (PTH) probe for UAS integration. A set of eight PTH probes were fabricated and calibrated/validated using an environmental chamber. An automated routine was developed to facilitate calibration and validation from a large set of temperature and relative humidity setpoints. Linear regression was used to apply temperature and relative humidity calibrations. Barometric pressure was calibrated using a 1-point method consisting of an offset. The resulting PTH probes were less than 4 g in mass and consumed less than 1 mA when operated from a 5 VDC source. Measurements were transmitted as a formatted string in ASCII format at 1 Hz over a 3.3 V TTL UART. Prior to calibration, measurements between individual PTH probes were significantly different. After calibration, no significant differences in temperature measurements across all PTH probes were observed, and the level of significance between PTH probes was reduced. Actual differences between calibrated PTH probes were likely to be negligible for most UAS-based applications, regardless of significance. RMSE across all calibrated PTH probes for the pressure, temperature, and relative humidity was less than 31 Pa, 0.13 °C, and 0.8% RH, respectively. The resulting calibrated PTH probes will improve the ability to quantify small variations in ambient conditions during coordinated multi-UAS flights.

Performance analysis of different air conditioning systems in apartment buildings under different climates in China

Liquid desiccant air conditioning (LDAC) system and solid desiccant air conditioning (SDAC) system have strong dehumidification capability. To evaluate and compare their feasibility and applicability, performance analysis of these two air conditioning systems and the conventional split air conditioning (AC) system in apartment buildings was conducted under different climates in China. Results show that SDAC system has the best temperature control and LDAC system has the best relative humidity control with the same requirements. In hot and humid cities, 45% relative humidity can be reached and stably maintained by LDAC system in summer when the relative humidity set point is 50%. While for apartment building controlled by split AC system and SDAC system, indoor air relative humidity could even reach 65% in summer. LDAC system is most efficient in hot and humid cities. In cold and dry cities, split AC system performs better than other two systems. Moreover, a dividing line between areas where LDAC system is more efficient and areas where split AC system is more efficient is developed in this paper. Areas where LDAC system is more efficient are mainly distributed in the coastal areas, Yangtze River basin and south of the Yangtze River.

Real-Time Cooling Power Attribution for Co-Located Data Center Rooms with Distinct Temperatures and Humidities

At present, a co-location data center often applies an identical and low temperature setpoint for its all server rooms. Although increasing the temperature setpoint is a rule-of-thumb approach to reducing the cooling energy usage, the tenants may have different mentalities and technical constraints in accepting higher temperature setpoints. Thus, supporting distinct temperature setpoints is desirable for a co-location data center in pursuing higher energy efficiency. This calls for a new cooling power attribution scheme to address the inter-room heat transfers that can be up to 9% of server load as shown in our real experiments. This article describes our approaches to estimating the inter-room heat transfers, using the estimates to rectify the metered power usages of the rooms’ air handling units, and fairly attributing the power usage of the shared cooling infrastructure (i.e., chiller and cooling tower) to server rooms by following the Shapley value principle. Extensive numeric experiments based on a widely accepted cooling system model are conducted to evaluate the effectiveness of the proposed cooling power attribution scheme. A case study suggests that the proposed scheme incentivizes rational tenants to adopt their highest acceptable temperature setpoints under a non-cooperative game setting. Further analysis considering distinct relative humidity setpoints shows that our proposed scheme also properly and inherently addresses the attribution of humidity control power.

Development and Evaluation of an Ultrasonic Humidifier to Control Humidity in a Cold Storage Room for Postharvest Quality Management of Dates

Dates are subjected to postharvest losses in quality and quantity caused by water loss, fermentation, insect infestation, and microbial spoilage during storage. Cold storage is the main element in the postharvest quality management used for fruit preservation. Although cold storage is used for dates, precision control of the relative humidity (RH) using ultrasonic applications is not used thus far, or it is applied to other fruits on a small scale. Therefore, we designed and constructed an ultrasonic humidifier (DUH) for RH control in the cold storage room (CSR) of dates. The optimum air velocity of 3 m s−1 at the outlets of the DUH ducts produced a mist amount of 6.8 kg h−1 with an average droplet diameter of 4.26 ± 1.43 µm at the applied voltage of 48 V and frequency of 2600 kHz of the transducers. The experimental validation was carried out by comparing a CSR controlled with the DUH with two conventional CSRs. The three tested CSRs were similar in dimensions, cooling system, and amount of stored dates. The time required for cooling 800 kg of dates in the controlled CSR from 25 °C to the target temperature of 5 °C was approximately 48 h. The DUH precisely controlled the RH at the maximum RH set point of 80% in the tested CSR at 5 °C. The controlled RH at 80% has a positive impact on the physicochemical characteristics of the stored dates. It significantly reduced the weight loss of the fruits and preserved fruit mass, moisture content, water activity, firmness, and color parameters. However, no significant effect was observed on fruit dimensions, sphericity, and aspect ratio. The microbial loads of mesophilic aerobic bacteria, molds, and yeasts fell within the acceptable limits in all tested CSRs. Both stored date fruits and artificially infested dates showed no signs of insect activity in the controlled CSR at the temperature of 5 °C and RH of 80%. The DUH proved to be a promising technology for postharvest quality management for dates during cold storage.

Semi-convertible Hydrogel Enabled Photoresponsive Lubrication

Summary A semi-convertible hydrogel with reversible photoresponsive supramolecular lubricating ability is demonstrated by integrating a responsive supramolecular system of α-cyclodextrins/polyethylene glycol (α-CD/PEG) and competitive guest 1-[p-(phenylazo)benzyl]pyridinium bromide (AzoPB) within a poly(vinyl alcohol) (PVA) and polyacrylamide (PAAm) framework. The competitive host-guest interaction between α-CD/PEG supramolecular network and AzoPB after UV and visible-light irradiation enables the appearance and disappearance of the sol-state layer on the hydrogel surface while the PVA and PAAm consistently keeps the framework. This semi-convertible process realizes the reversible photoresponsive lubricating ability and variable toughness. We envision that this finding will offer a possible way for fabricating novel smart devices far beyond lubrication, leading to an emerging branch of interdisciplinary materials science that integrates supramolecular chemistry, hydrogel, and surface science.

Optimisation of energy-efficient greenhouses based on an integrated energy demand-yield production model

The aim of this paper is to develop a simulation framework to minimise the cost associated with commercial greenhouse yields (production cost). Greenhouse energy demand and yield production models are coupled with a cost model to investigate the interaction between energy consumption costs and yield production benefits. The coupled model is defined as an optimisation problem to determine the optimal values of decision variables (e.g. cover material, heating and cooling technology, inside temperature and relative humidity set points, plant density, etc.), which result in minimum production cost as the objective function. The results show that the integrated energy demand-crop yield production model outperforms the “classical approach” of a separate energy consumption model where yield is not explicitly modelled but only considered by constraints warranting good growing conditions. In the case of a tomato greenhouse in Iran, the financial cost and environmental impact of producing a 1 kg yield based on integrated energy demand-yield production model were 49% and 29% lower than the energy-consumption model alone. Moreover, the impact of fuel prices on the optimisation results is investigated by use of the proposed framework. Considering real fuel prices instead of current subsidised fuel prices in the Iranian case study, 70% of energy consumption and 19% of climate change impacts could be eliminated while increasing the production cost by 17%. Selling the saved fuel at real prices to other customers would provide the government with more than enough money to compensate the farmers for the increased yield cost. • Greenhouse energy demand and yield production models are coupled with a cost model. • The coupled model is optimised to minimise the production cost. • Optimisation based on coupled model outperforms classical greenhouse energy-optimisation. • The resulted production cost is 49% lower than classical approaches. • Removing fuel subsidies would increase production costs by 17% and decrease CO 2 emissions by 19%.

Acceptable air velocities using demand-controlled ventilation for individual cooling

One of the main challenges in highly insulated buildings is the increasing share of energy demand for cooling. New solutions for low energy cooling are needed. Individual cooling by demand-controlled ventilation and use of ceiling mounted nozzles for cooling by higher air velocities could be an alternative. A laboratory study was designed to investigate thermal comfort and thermal sensation for elevated indoor room temperatures relevant to Norwegian summer climate; 24℃, 26℃ and 28℃ with a relative humidity set point of 40 %. Air flow was set to give air velocities of 0.25 m/s, 0.50 m/s and 0.75 m/s. 21 test persons were exposed to different air velocities in a cross-over study. Questionnaires on thermal comfort and thermal sensation were answered repeatedly. Jets from ceiling mounted supply air nozzles was shown to improve thermal comfort at 24 °C, 26 °C and 28 °C. In general, most test persons preferred low air velocity (0.25 m/s) at 24 °C, while high (0.5 m/s) or extra high (0.75 m/s) air velocities were preferred at 26 °C. At 28 °C, extra high or even higher air velocities were preferred.

Nonlinear model predictive control of a climatization system using rigorous nonlinear model

Buildings are known for being great consumers of energy and for operating under On/Off and linear control strategies in common commercial packages. In order to reduce their energy footprints and to improve thermal comfort, new methodologies are needed to obtain better input profiles. This paper presents a detailed study of the implementation of a nonlinear model predictive control (NMPC) approach for a heating, ventilation, and air conditioning (HVAC) system. The HVAC system is modeled by an index-1 differential-algebraic system of equations, obtained from rigorous material and energy balances. The proposed NMPC algorithm was implemented in GAMS and compared with another approach from the literature. Similarly, the objective function is defined using one or more of the following criteria: (1) tracking of temperature and relative humidity set points; (2) maximization of thermal comfort; (3) minimization of energy consumption. To better represent the situation in a real application, the simulations include model-plant mismatch in parameters such as air infiltration into the building, the coefficient of the thermal exchange between the building and the exterior, and occupancy level. Additionally, simulations with random measurement noise have been performed. The results have shown that the proposed approach, in which the model is not linearized at any step, is able to reduce the energy consumption and maintain the Predicted Mean Vote (PMV) close to the desired set point, while the computation burden is only increased by one second per iteration, which is negligible in comparison with a sampling time of 10 min.

Rapid humidity regulation by mixing of dry and humid gases with feedback control for PEM fuel cells

Abstract Humidity regulation in fuel cells utilizing bulk mass transfer and membrane-based methodologies have drawbacks and limitations, which are undesirable during fuel cell operation. In this work, we demonstrate a rapid and nearly accurate humidity control by mixing of dry and humidified gas streams for tracking predefined relative humidity set points. The humidity responses from the mixed stream could track various relative humidity profiles when coupled with feedback to PI and PID control algorithms. A discussion on the usefulness of this method for controlling the humidification of fuel cell inlet gases, its effectiveness and limitations under high frequency operation are provided.

Multi-objective optimization of microclimate in museums for concurrent reduction of energy needs, visitors’ discomfort and artwork preservation risks

In museums, hygrothermal conditions must be carefully controlled by HVAC system to avoid artwork degradation. Higher energy requirements are needed for the maintenance of the suitable thermal environment. Moreover, a comfortable thermal sensation is needed for a positive museum experience. In light of current policies on energy efficiency, we propose an original procedure for the concurrent achievement of three goals: artwork preservation, energy efficiency, and human thermal comfort. This procedure is based on the application of multi-objective optimization and aims at correctly choosing temperature and relative humidity setpoints, through the use of dynamic simulations and evaluation of three indexes as objectives. This strategy can be particularly effective in museums hosted in historic buildings, where envelope and HVAC refurbishment is often forbidden or discouraged due to the architectural constraints. Furthermore, the retrofit action is almost costless. A case study is presented: first, a monitoring campaign in an Italian museum has been used for the validation of dynamic simulation models of the building-HVAC system; then, the validated models have been used to show that improvements of artwork lifetime, human thermal comfort and reduction of energy requirements of the HVAC system are possible, if currently-used hygrothermal setpoints (based on technical standards and guidelines) are replaced with those identified by the optimization problem.

Performance optimization of a demand controlled ventilation system by long term monitoring

The thermo-hygrometric treatment related to the air change in buildings requires a relevant quota of the total energy demand of HVAC systems, especially when the ventilation demand is significant. A correct energy saving strategy therefore should always focus on the use of suitable techniques to reduce this energy consumption. As proved by the modern theories on comfort, less strict values can be accepted for the internal humidity set points without compromising indoor comfort conditions. In addition, Demand Controlled Ventilation (DCV) gives the opportunity to reduce energy requirements. This paper investigates the opportunities offered by the installation of a DCV system and a Building Management System (BMS) able to perform long term monitoring of the HVAC system in a real case study. This refers to a historic building in Venice in the area of the harbour and recently transformed into a modern university facility. Starting from the experimental data recorded by BMS, an optimization of the control strategies and simple tuning actions of the DCV controller were possible. Results validate the use of more flexible set points of indoor relative humidity and long term on-line tuning even in absence of self-learning control systems, as well as they highlight the achievement of remarkable energy savings thanks to these actions. The research demonstrates the fundamental contribution of successive control performance assessments by long term monitoring to individuate possible weaknesses in DCV system management.

Dynamic setpoint calculation including collection and comfort requirements: Energy impact for museums in Southern Europe

Firstly, this study presents an algorithm for setpoint calculation of museums’ indoor temperature (T) and relative humidity (RH) integrating collection requirements according to ASHRAE and thermal comfort requirements according to adaptive temperature limits that follow from a one-year long comfort study in case study museum Hermitage Amsterdam. Secondly, this algorithm is implemented into a building energy simulation model to assess the energy impact for various cases: Five levels of museum indoor climate conditioning are applied to four building quality levels (ranging from a historical building to a purpose-built museum building) using weather data from six locations in Southern Europe. A validated building energy simulation model of museum Hermitage Amsterdam was adjusted to represent the four building quality levels, and technical-reference-year (TRY) weather data of six locations were used. The conclusions: The algorithm enables smooth control of hourly and seasonal adjustments in T and RH setpoints; the algorithm boosts energy efficiency due to more effective use of the permissible ranges of T and RH; improving the building quality quickly follows the law of diminishing returns due to internal heat and moisture loads; supposing to result in the same collection risk, subclass As (with seasonal adjustments, but smaller hourly fluctuations) is more energy efficient than subclass Ad (no seasonal adjustments, but larger hourly fluctuations) for most locations.

Heat-pump dehumidifier as an efficient device to prevent condensation in horticultural greenhouses

In the context of increasing energy costs, alternative methods to the energy consuming venting-heating method must be considered for greenhouse dehumidification. In this paper the performance of a heat pump used as a dehumidifier is investigated. Contrary to the classical control aiming at maintaining the greenhouse air at a relative humidity set point, the considered device is designed as a preventive tool to avoid condensation on the crop and limit the energy consumption. The experimental set up was run during winter inside a 2350 m2 plastic greenhouse in the West of France for a set temperature of 16 C. During the experiment, no condensation occurred on the plants with a mean condensation rate of 12 W m 2 and a mean electrical power of 7.62 kW, for an overall efficiency of 4.9. Moreover, the energy retrieved by vapour condensation was given back to the greenhouse as sensible heat, contributing to the total heating of the greenhouse. While dehumidifying the greenhouse air, the device reduces, or may even rule out the gas consumption. The total energy consumption of the heat pump during the season was compared to simulated values for venting-heating dehumidification, with or without an exchanger. The heat pump dehumidifier was shown to be 6 to 8.5 times less energy consuming than the former and 3-8 than the latter, depending on the exterior climate. Using the energy cost of several significant countries, a preliminary operative cost study was conducted and showed that the heat pump can be competitive as a dehumidification alternative.

Integrated numerical and experimental methodology for thermal-energy analysis and optimization of heritage museum buildings

Research effort was dedicated to the analysis of museums microclimate for the preservation of artifacts and indoor environment. In this paper, continuous monitoring and dynamic simulation of an ancient exhibition site are carried out to evaluate indoor microclimate and energy performance. The aim is to develop a multidisciplinary methodology for preserving artworks and historic buildings in the view of sustainability and comfort. The paper also shows how the environmental conditions of two thermal zones different for geometry, occupancy, ventilation rate, and heating, ventilation, and air conditioning (HVAC) systems are far from the values suggested by the regulations for the preservation of artifacts and from human comfortable set points of temperature and relative humidity. This work highlights the need for further investigation of historical exposition sites to reduce artworks' damaging and occupants' environmental stress. Practical application: Many historical buildings in European countries host exhibition sites. Indoor microclimate of such areas is often inappropriate for visitors' comfort, for artworks', and building preservation. In fact, usually HVAC systems operate according to simple temperature-based control protocols. This study shows how old architectures could present indoor environmental conditions far from the target, for artworks' preservation, for occupants' comfort, and for the building maintenance. This paper presents a numerical–experimental methodology applied to an architectural heritage. The analysis gives insight on this issue, and could guide building operators and service management to investigate and optimize indoor environmental conditions where artworks are preserved.

Analyzing the effects of comfort relaxation on energy demand flexibility of buildings: A multiobjective optimization approach

We present a multiobjective optimization framework to evaluate the effects of comfort relaxation on the energy demands of buildings. This work is motivated by recent interest in understanding demand elasticity available for real-time electricity market operations and demand response events. We analyze the flexibility provided by an economics-based control architecture that directly minimizes total energy and by a traditional tracking control system that minimizes deviations from reference temperature and relative humidity set-points. Our study provides the following insights: (i) using percentage mean vote (PMV) and predicted percentage dissatisfied (PPD) constraints within an economics-based system consistently gives the most flexibility as comfort is relaxed, (ii) using PMV and PPD penalization objectives results in high comfort volatility, (iii) using temperature and relative humidity bounds severely overestimates flexibility, and (iv) tracking control offers limited flexibility even if used with optimal set-back conditions. We present a strategy to approximate nonlinear comfort regions using linear polyhedral regions, and we demonstrate that this reduces the computational complexity of optimal control formulations.

Performance Evaluation of the Brechtel Mfg. Humidified Tandem Differential Mobility Analyzer (BMI HTDMA) for Studying Hygroscopic Properties of Aerosol Particles

The Tandem Differential Mobility Analyzer (TDMA) technique coupled with aerosol humidification has been widely used for studying aerosol hygroscopicity. In this study, we evaluate the performance of a commercial Humidified TDMA (BMI HTDMA, Model 3002) with respect to DMA sizing, relative humidity (RH) control, and growth factor (GF) measurements. Unique features of this particular HTDMA include a diffusion-based particle humidifier, a DMA design allowing selection of particles up to 2 μm diameter at only 5600 volts, and the ability to study the complete deliquescence and efflorescence cycle. The sizing agreement between DMA 1 and 2 was within 2% over the 35 to 500 nm diameter range. The measured TDMA responses agreed well with theoretical calculations. The RH control and stability were tested at a suburban field site in Hong Kong. The system achieved RH equilibrium in less than 4 min when changing the RH set point. With indoor temperature changes of less than 1°C per hour, the RH control of the system was...

Fluctuations in relative humidity provided to extremely low‐birthweight infants (R1)

In extremely low-birthweight infants, the addition of relative humidity (RH) improves thermal stability, fluid and electrolyte balance. However, during routine care this microenvironment is frequently disturbed. The objective of this study was to determine the frequency, magnitude and direction of fluctuations in RH provided to extremely low-birthweight infants. All infants in our study had ambient temperature and RH continuously recorded for 48 h using a datalogger device (RH32S-C2). A clinically acceptable range for RH was defined as the set point ± 10%. A secondary analysis was performed to compare outcomes between infants that spent > 50% of the time out-of-range (OOR) or inside the range (IR). A P-value < 0.05 was significant. A total of 20 infants were included. Important fluctuations were detected by the device with infants spending 40% and 14% of the time above and below the range, respectively. However, the RH set point did not differ from the mean levels measured over 48 h by the RH32S-C2 or the incubator. Infants in the OOR group spent significantly more time at values higher than the planned range when compared to IR infants. Although significant fluctuations in RH above the desired range were detected in more than half of the infants, the average values were similar to the set points. Nevertheless, knowledge of these dynamic changes may help to optimize individualized care.

Using EnergyPlus to perform dehumidification analysis on Building America homes

A parametric study was conducted using EnergyPlus version 6.0 to investigate humidity issues on a typical mid-1990s reference home, a 2006 International Energy Conservation Code home, and a high-performance home in a hot–humid climate. The impacts of various dehumidification equipment and controls are analyzed on the high-performance home. The study used the Walker and Wilson (1998) infiltration model to examine the combined effects of infiltration and mechanical ventilation with balanced and unbalanced mechanical ventilation systems. Indoor relative humidity excursions were examined—specifically, the number of excursions, average excursion length, and maximum excursion length. Space relative humidity, thermal comfort, and whole-house source energy consumption were analyzed for indoor relative humidity set-points of 50%, 55%, and 60%. The study showed and explained why similar trends of high humidity were observed in all three homes, regardless of energy efficiency, and why humidity problems are not necessarily unique in high-performance homes. Thermal comfort analysis indicated that occupants are unlikely to notice indoor humidity problems. The study confirmed that supplemental dehumidification should be provided to maintain space relative humidity below 60% in a hot–humid climate. All modeled supplemental dehumidification options successfully controlled space relative humidity excursions, yet the increase in whole-house energy consumption was much more sensitive to the humidity set-points than the chosen technology option.