Browse Forums Kitchen Corner 1 Dec 14, 2008 1:34 pm Hi, my builder provides a stainless steel canopy slimline rangehood (Blanco BRC90BX). I am just wondering if I need to ask to change into a wall canopy one. I stir fry food a lot and I am not sure which kind of ranghood is the most effective? TA Re: which ranghood is better, wall canopy/ slide-out/ slimline? 3Dec 14, 2008 4:56 pm Paddy05 A canopy is more powerful as far as I am aware. A Canopy is more effective for a given airflow due to its aerodynamics. Important factors to consider: - Remember power is important but isn't everything. The design, installation and setup is also critical. - BEWARE how manufacturers quote air flow. There are few local standards governing airflow ratings (cfm, cubic feet per minute, cubic metres per hour). The bench flow rates will be different once you connect the duct work and accessories up. The more bends, constrictions and intervening components will decrease the effective flow. European standards quote the flow on a standard length ductwork and 2 bends. Expect at least 10% between quoted difference of flow rates and effective flow rates in non-European brands. - Good installation is critical to effective flow. The duct work ideally should be as straight as impossible from range hood to exhaust. Connections should avoid any abrupt transitions, bends or constrictions. - The best set up is where the exhaust area is enclosed. Canopy hood with two side extensions and against the wall. The least efficient setup is an island bench with the unit open on all sides. You will need a much higher flow rate to achieve the same result. - The front edge of the canopy ideally should protrude further than the edge of the cooktop to capture the gases. - Ensure there are no random breezes from windows and vents near the hood which blow the cooktop smoke around and reduce the effectiveness of the unit. - Allow a source of 'make-up' air to replenish the exhausted gases i.e. don't have the range hood going full bore with the kitchen doors closed tight. Eventually a partial vacuum builds up in the kitchen and strains the motor which then reduces its effective flow rate. The simple rule is 'air going out = air going in' - Clean your grilles often to reduce resistances and improve flow rates Re: which ranghood is better, wall canopy/ slide-out/ slimline? 4Dec 14, 2008 9:43 pm [ Good installation is critical to effective flow. ............ The best set up is where the exhaust area is enclosed. Canopy hood with two side extensions and against the wall. The least efficient setup is an island bench with the unit open on all sides. You will need a much higher flow rate to achieve the same result. ......Ensure there are no random breezes from windows and vents near the hood which blow the cooktop smoke around and reduce the effectiveness of the unit]
thanks a lot for your advice!! I don't know how the builder will instal the rangehood. However, I am going to have a window near the cooktop(=rangehood), as I want fresh air and more light. In your opinion, for a double-storeyed house, is it better to let the exhaust off through the vent in the roof (as the builder will normally do) or vent straight outside house in the ground floor? TA Re: which ranghood is better, wall canopy/ slide-out/ slimline? 6Dec 15, 2008 12:12 am Mango-lover is it better to let the exhaust off through the vent in the roof (as the builder will normally do) or vent straight outside house in the ground floor? TA I would try to track down a specialist in fan exhaust systems e.g. Fantech. They can determine the most efficient system based on duct run and number of bends. Short and straight is better than long and bendy. There are rough rules of thumb to work this out yourself. Essentially you need to know the pressure/flow curve of the fan unit and then calculate the static pressure of the system to predict flow rates. Re: which ranghood is better, wall canopy/ slide-out/ slimline? 7Dec 15, 2008 12:12 am * oops double post I don't know them all, the first 2 top of your list are best known. Rylock is a good company, Stegbar is for sale. 4 16191 brokers will also be in a position to get you a better rate than the advertised rate most times. 6 7561 Thank you again Simeon.. I will call my certifier for that. Have a good day 4 5141 |